JP5072074B2 - Double-sided stencil printing machine - Google Patents

Description

  The present invention relates to a double-sided stencil printing apparatus.

  In general, a laminate structure in which a thermoplastic resin film having a thickness of approximately 1 to 2 μm and a porous support made of Japanese paper fiber or synthetic fiber or a mixture of Japanese paper fiber and synthetic fiber are bonded together. The stencil master (hereinafter simply referred to as “master”) is brought into contact with the heat generating element of the thermal head, and the thermal head is punched and stenciled through the operation in the main scanning direction. A master transporting means such as a platen roller moves the master (hereinafter, sometimes referred to as “a master that has been prepressed”) in the sub-scanning direction (master transporting direction) perpendicular to the main scanning direction, for example, resin Alternatively, a mesh screen made of a metal mesh body is wound around a porous cylindrical rotatable plate cylinder having a structure in which multiple layers are wound, and is provided inside the plate cylinder. Ink is supplied from the ink supply member to the master made on the plate cylinder on the plate cylinder, and the plate on the plate cylinder is pressed by a press means called a press roller, an impression cylinder, or an intermediate press roller (hereinafter referred to as “press roller”). Printing paper (hereinafter simply referred to as “paper”) as an example of a sheet-like recording medium is directly and continuously pressed against the finished master, and ink is oozed out from the opening portion of the plate cylinder and the perforation portion of the master. A thermal digital double-sided stencil printing apparatus (hereinafter simply referred to as a stencil printing apparatus) that performs stencil printing by transferring to paper is known. Also known is a stencil transfer printing apparatus that temporarily transfers ink that has oozed from the opening portion of the plate cylinder to a transfer cylinder having a rubber sheet, and then indirectly prints it on paper (see, for example, Patent Document 1). ). The “plate cylinder” is also referred to as a printing drum in this specification.

  In the above-described stencil printing, in addition to single-sided printing that prints only on one side of the paper, in recent years, printing is performed on both front and back sides of the paper for the purpose of reducing paper consumption and document storage space. Double-sided printing has come to dominate.

  As such a printing apparatus capable of duplex printing, it has plate making means for making a master as a master divided into two front and rear sides in the feed direction of the stencil sheet, and is pressed against the outer surface of the printing drum rotating at a predetermined peripheral speed. In the case where printing is performed on each of the two surfaces by replacing the front and back of the paper to be printed with a press roller that is rotatably arranged, a drum rotation angle information detecting unit that detects drum rotation angle information of the printing drum, The moving guide that receives and holds the paper printed on the first surface of the two surfaces, the conveying belt means that conveys the paper, and the feeding amount and speed of the paper can be controlled by the conveying belt means. A conveyance motor, a stopper release mechanism for releasing contact between the paper and the stopper when printing the second surface of the two surfaces, and contact of the stopper with the paper. And it conveys the the paper, duplex stencil printing device for refeeding to the printing position while reversing the front and back of the paper is known (e.g., see Patent Document 2).

  In such a conventional double-sided stencil printing apparatus, when the sheet is conveyed by the conveying belt means and the leading end of the sheet in the advancing direction is brought into contact with the stopper, the sheet is bent between the conveying belt means and the stopper. There is no problem if the amount of deflection of the sheet is always constant, but the amount of deflection varies depending on the environment and the type of sheet and is not constant. Therefore, when the stopper is released in a state of a certain amount of deflection, and the paper is conveyed by driving the press roller while pressing the registration roller through the paper against the press roller, compared with the case of a state of a different amount of deflection. As a result, the position of the leading edge of the paper is shifted by the amount of deflection, and the printing surface start position of the stencil stencil sheet wound around the printing drum is shifted from the leading edge position of the paper, so that the image position is shifted. , The resist will be shifted.

  On the other hand, in a stencil printing apparatus that is not double-sided printing, the paper fed from the paper feed tray is transported toward the printing drum by the transport roller, and printing is started when it reaches the contact point (nip) between the printing drum and the press roller. In such a stencil printing apparatus, when the printing start position of the paper reaches the contact point, the paper is wound around the printing drum in order to align the printing range of the paper and the printing surface range of the stencil stencil sheet. It is also necessary that the stamping surface start position of the stencil-made stencil sheet thus made reaches the contact point.

  Therefore, for example, the printing paper is made to stand by in contact with a so-called registration roller, and when the printing drum rotates to a predetermined position, the registration roller is started to rotate at a preset rotation speed, thereby starting printing of the paper. There has been proposed a method for matching the position with the printing face start position of the stencil sheet. However, in this method, slip occurs in the course of conveyance by the registration roller, or there is variation in the slack of the printing paper that occurs when the paper is in contact with the registration roller. Therefore, the registration roller is preset as described above. If it is controlled to rotate at the rotation speed, it is difficult to always match the printing surface start position with the printing start position.

  In addition, a registration sensor for detecting the leading edge of the paper being conveyed is provided between the registration roller and the contact point, and the drum rotation angle information of the printing drum at the time when the leading edge of the paper is detected by the registration sensor is obtained. Based on the rotation angle information, it is conveyed so that the time until the printing surface start position of the stencil stencil sheet reaches the contact point matches the time until the printing start position of the paper reaches the contact point from the position of the registration sensor. A method for controlling the rotational speed of the roller has been proposed.

  In the stencil printing apparatus as described above, it is necessary to make the paper conveyance speed coincide with the peripheral speed of the printing drum at the start of printing, that is, when the paper reaches the contact point between the printing drum and the press roller.

  Therefore, when the printing paper is conveyed in an ideal state, the timing at which the leading edge of the paper is detected by the registration sensor is acquired in advance as an ideal value, and the registration roller from the point when the printing drum rotates to a predetermined position to the ideal value. Is rotated at a predetermined acceleration, and then the registration roller is temporarily rotated at a constant rotation speed, and then the registration roller is rotated at a predetermined acceleration until the sheet conveyance speed and the peripheral speed of the printing drum become the same again. At the same time, the leading edge of the sheet is detected by the registration sensor while the sheet is being conveyed by the rotation at the constant rotation speed, and the acceleration is started again according to the delay from the ideal value of the detection timing. Thus, there has been proposed a method of correcting the printing position so that the printing start position of the paper matches the printing face start position of the stencil sheet.

  As an example, a paper leading edge detection sensor is provided on the downstream side of the pair of feed rollers to detect the leading edge of the paper that has passed through the pair of rollers, and from the relationship with the rotational position of the plate cylinder at that time, There is a technique for detecting the slow speed of feeding and controlling the rotation of the motor for feeding the paper to be accelerated or decelerated according to the detection result so that the leading edge of the paper and the leading edge of the master coincide in the printing unit ( For example, see Patent Document 3).

  As another example, the registration motor is driven and controlled at a constant acceleration until the printing paper leading edge detection time N1 by the registration sensor, and is driven and controlled at a constant rotational speed from N1 for a predetermined period FGx. Is driven again at a constant acceleration so that the paper conveyance speed by the registration rollers coincides with the peripheral speed of the printing drum, and based on the drum rotation angle information of the printing drum at the time when the leading edge of the printing paper is detected, There is a technique for calculating the predetermined period FCx so that the printing start position and the printing surface start position of the stencil sheet after printing are coincident at the contact point between the printing drum and the press roller (see, for example, Patent Document 4).

  As another example, the main body sheet feeding control device controls the registration motor so that the leading edge of the sheet is sent out at the first sheet conveyance speed vp1 until the leading edge of the sheet comes into contact with the sheet clamper during bank-side feeding. The registration motor is controlled so that the sheet is sent out at the second sheet conveyance speed vp2 from the time when the leading edge of the sheet comes into contact with and held by the sheet clamper and before the start of the printing pressure. The registration motor is controlled so as to send out the paper at the third paper conveyance speed vp3, and after the start of the printing pressure, the registration motor is controlled so that the resist roller again sends out the paper at the second paper conveyance speed vp2. There is a technique (see, for example, Patent Document 5).

However, (1) Patent Documents 3 and 4 are not related to the double-sided stencil printing apparatus. By increasing the speed of the registration rollers, the conveyance rollers easily slip. In addition, the image position may be shifted from the ideal position.
(2) With respect to Patent Document 5, after the printing start position of the paper coincides with the printing face start position of the stencil stencil sheet, the rotational speed of the printing drum is detected up to the contact point between the printing drum and the press roller. It is operating at the same speed as that speed. However, the printing drum does not rotate at a constant speed. The peripheral speed of the printing drum is increased or decreased depending on the case where the press roller contacts the printing drum or the environment. Even if the speed of the printing drum is detected, the speed change is measured, and the speed of the registration roller is changed, it is difficult to follow 100%. In addition, the larger the speed irregularity (wah-fla) of the printing drum, the greater the deviation.

JP-A-6-48014 JP 2006-224633 A Japanese Patent No. 3492932 (see claim 1 and paragraph 0063) JP 2006-103171 A (see summary and claim 1) JP 2000-158780 A (see summary and claim 1)

  In view of the above circumstances, the present invention provides a double-sided stencil printing apparatus in which the printing start position of the paper and the printing face start position of the stencil-made stencil sheet are made to coincide with each other with high accuracy at the nip position between the printing drum and the press roller. It is an object of the present invention to provide a double-sided stencil printing apparatus that performs printing with no ink.

The present invention has the following configuration in order to achieve the above object.
Rotation claimed invention according to claim 1, a stencil making means for plate making as a master is divided into two front and rear sides in the feeding direction of the stencil sheet, is pressed against the outer surface of the printing drum and the printing drum rotating at a predetermined peripheral speed a press roller which the installed possible, the drum rotation angle information detecting means for detecting the drum rotation angle information of the printing drum, second surface prior SL when printing each by the two planes by replacing the front and back of the paper to be printed movement guide and a conveying belt means for conveying the sheet, the conveyance motor capable of controlling the feed amount and speed of the sheet by the conveying belt means for receiving the printed sheets by the first surface contacts held in the Then, after printing on the first surface, when printing on the second surface, the paper abuts on the paper conveyed by the conveyor belt, temporarily stops its progress, and then releases the stop To Tsu a path and a stopper release mechanism for releasing the contact between the paper and the stopper when printing before Symbol second surface, nip between the press roller and the printing drum, the city, the first after printing one side, duplex stencil that after temporarily stopping the progress of the paper when printing on the second surface to convey the the paper, to refeeding to the printing position while reversing the front and back of the sheet It met the printing device,
Having a leading edge detecting means for detecting the leading edge of the paper on the downstream side of the stopper;
The transport motor is a step motor controlled by subtracting the paper feed amount from the stopper to the nip part from a feed amount theoretical value indicated by the number of steps,
The transport belt is operated at a transport speed faster than the peripheral speed of the printing drum after the contact of the stopper with the paper is released,
At the time when the leading edge of the sheet transported after the release of the contact is detected by the leading edge detection means, the leading edge of the sheet from the stopper reaches the leading edge detection means . Compare the feed amount theoretical value with the feed amount actually transported and detected to find the difference in feed amount ,
Of the feeding range from the stopper to the nip portion of the paper, the remainder from the position of the leading edge detection means to the nip portion except for the stopper to the leading edge detection means is the theoretical value. together to correct the feeding amount of該残Ri using the difference of the feed amount such that,
The difference between the remaining distance from the detection position by the drum rotation angle information detection means to the nip portion and the feed amount of the stencil sheet that has been wound around the printing drum is corrected. , Comparing the remaining distance until the leading edge of the paper reaches the nip portion from the leading edge detection means ,
By making the transport speed of the transport belt equal to the peripheral speed of the printing drum when these distances are equal,
The leading edge position of the paper is controlled so as to match the printing face start position of the stencil sheet after the plate making.
The invention according to claim 2 is the double-sided stencil printing apparatus according to claim 1,
A registration auxiliary roller that can be freely contacted and separated from the press roller, and when the paper leading edge position matches the printing surface start position of the stencil sheet after making a plate based on the drum rotation angle information by the drum rotation angle information detecting means, The resist auxiliary roller is brought into contact with the press roller.
The invention according to claim 3 is the double-sided stencil printing apparatus according to claim 1,
After the peripheral speed of the printing drum and the transport speed of the transport belt become equal, the transport motor performs the time of the transport motor based on the output signal of the drum rotation angle information detection means by the drum rotation angle information detection means. The feedback control is performed to change the hit feed amount.
According to a fourth aspect of the present invention, in the double-sided stencil printing apparatus according to any one of the first to third aspects, the distance of the outer periphery of the printing drum at the minimum step angle of the drum rotation angle information detecting means and the minimum feed of the transport motor. We decided to make the quantity equivalent or multiple.

According to the first aspect of the present invention, the conveyance speed of the conveyance belt can be changed at least in two stages without complicated control: a speed equivalent to the circumferential speed of the printing drum and a speed faster than the circumferential speed of the printing drum. In this way, the leading edge of the sheet and the stamping surface start position can be more accurately matched with the control with a small burden on the control unit .
In the second aspect of the invention , the paper is pressed by the auxiliary roller against the press roller rotating at the same peripheral speed as the printing drum and conveyed at the same speed as the press roller. The paper is sent without being affected, and the printing start position of the paper and the printing face start position of the pre-made stencil sheet match at the nip position.
According to the third aspect of the present invention, after the peripheral speed of the printing drum and the conveying speed of the conveying belt are made equal, even if rotation irregularities occur in the printing drum, the printing start position of the paper and the start of the printing surface of the stencil stencil are made. it is possible to I if the position at the nip position.
According to the fourth aspect of the present invention, the print start position of the printing paper is obtained by making the distance of the outer periphery of the printing drum at the minimum step angle of the drum rotation angle information detection means equal to or a multiple of the minimum feed amount of the transport motor. that Do easily controlled to match the print face starting position for making a pre stencil with.

[1] Double-sided stencil printing machine

  Hereinafter, an embodiment (hereinafter referred to as “embodiment”) according to a double-sided image forming apparatus as an example suitable for carrying out the present invention will be described with reference to the drawings. Constituent elements such as members and components having the same function and shape throughout the embodiment and the modified examples are given the same reference numerals and will not be described after being described once. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When a constituent element such as a published patent gazette is cited and explained as it is, the reference numeral is attached with parentheses to distinguish it from that of each embodiment.

First, the overall configuration of the double-sided stencil printing apparatus 300 will be described with reference to FIG.
In the double-sided stencil printing apparatus 300, as shown on the upper left side of the figure, a master 8 wound in a roll shape (the state before stencil making is sometimes called a stencil sheet, but in the present invention, it is called a master through before and after stencil making) A plate making unit 15 for making a plate, and a plate cylinder 1 for winding a plate-made master around the outer peripheral surface as shown in the substantially central part of the figure, and an ink supply to be described later for supplying ink to the plate-making master on the plate cylinder 1 And a printing section 16 having a press roller 21 as a pressing means that presses the sheet 36 against a master made on the plate cylinder 1, which is detachable from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1. Is disposed opposite to the plate making unit 15 with the used master on the plate cylinder 1 peeled and discharged, and disposed on the lower side of the plate discharging unit 17 on a sheet feeding tray 35 serving as a sheet feeding table. The paper 36 is fed toward the printing unit 16. The paper unit 30 and a paper discharge unit that is disposed below the plate making unit 15 so as to face the paper supply unit 30 and separates the printed paper 36 from the plate cylinder 1 and discharges it to a paper discharge tray 172 serving as a paper discharge tray. 19, a main body frame 130 as an apparatus main body as shown in FIG. 12 in which the plate cylinder 1, the plate making unit 15, and the plate discharging unit 17 are arranged, and a document 133 that is arranged on the upper part and is transferred from the document receiving table 134. And an image reading unit 18 for reading an image such as a document (not shown) placed on a contact glass 135 as a reading unit.

  Further, the double-sided stencil printing apparatus 300 temporarily holds the surface-printed paper on which the printed image is formed on the surface thereof as described later, and then directs the surface-printed paper toward the press roller 21. A refeeding unit 48 that is reversed by the delivery press roller 21 and refeeds toward the printing unit 16, and a sheet that has passed through the printing unit 16 (surface-printed paper or double-sided printed paper) And a switching guide 46 as switching means for guiding to the paper discharge unit 19.

  1 to 8, the refeed unit 48 includes a front end portion including the front end of the front surface printed paper 36 a sent out from the printing unit 16 (hereinafter sometimes referred to as “front end”) in the vicinity of the printing unit 16. The surface is held at the initial position P2 (or standby position P2) as the second position in the vicinity of the upstream side of the refeeding means 45 lower than the movement position P1. A moving guide 81 as a sheet clamping means (sheet holding means) for releasing the leading end of the printed sheet, and a moving means 87 for reciprocating the moving guide 81 between the moving position P1 and the initial position P2 as shown in FIG. As shown in FIG. 8, when the movement guide 81 occupies the movement position P1, the movement guide 81 is opened once and then operated so as to clamp the front end of the surface printed paper. Occupying initial position P2 The release cam 98 and the release pin 99 constituting the operation timing control means for operating the movement guide 81 so as to open the front end of the surface printed paper, and the movement guide 81 as shown in FIGS. Re-feeding that temporarily holds the surface-printed paper delivered from the printer, then feeds the paper with the surface-printed toward the press roller 21, reverses it with the press roller 21, and re-feeds it toward the printing unit 16. Means 45 and the like.

  As described above, the double-sided stencil printing apparatus 300 includes a single ink supply unit, a single plate cylinder 1 and a single press roller 21, and makes one rotation of the plate cylinder 1 as described later. Therefore, a one-plate cylinder 1-pressing means double-sided printing method capable of printing on both sides of the paper is adopted. The plate making unit 15, printing unit 16, discharge plate unit 17, paper feeding unit 30, paper discharge unit 19, image reading unit 18, refeeding unit 45 in the refeeding unit 48, moving guide 81, moving unit 87, The operation timing control means and the switching guide 46 are each configured as a device as will be described later.

  The plate making unit 15 performs plate making on the master 8 and, as shown in FIG. 9, the first plate making image for surface printing along the rotation direction of the plate cylinder 1 (which is also the paper carrying direction X and the master carrying direction X1). Master plate 8X for double-sided printing (hereinafter referred to as “backside plate-making image 8B”) and 8A (hereinafter referred to as “front-side plate-making image 8A”) and second plate-making image 8B for backside printing (hereinafter referred to as “backside plate-making image 8B”). In other words, it is referred to as “divided plate making master 8X”), or as shown in FIG. 3, a third plate area having two image areas of the front plate making image 8A and the back plate making image 8B along the rotation direction of the plate cylinder 1. It has a function / configuration for producing a master-making master 8Y having a plate-making image 8YA (hereinafter referred to as “single-side plate-making image 8YA”). The front plate-making image 8A is formed at a position corresponding to the surface region 1A shown in FIG. 1 when the divided plate-making master 8X is wound on the outer peripheral surface of the plate cylinder 1, and the back plate-making image 8B is the same as the back surface region 1B. And corresponding positions.

  In FIG. 1 and FIG. 9 and the like, the master-made master 8Y is indicated with parentheses to distinguish it from the divided master-made master 8X. In FIG. 9, the area range of the single-side plate-making image 8YA formed on the plate-making master 8Y is indicated by a two-dot chain line, and the boundary line of the same area range in the master transport direction X1 is the solid line of the front-side plate-making image 8A and the back-side plate-making image 8B. Because of the overlap, the area range is shown to be slightly larger. However, the area range of the single-side plate-making image 8YA is a front-side plate-making image 8A, a back-side plate-making image 8B, and an unfinished blank area that is located between them. This is the entire range including the plate making area 8C.

  The plate making unit 15 includes a master support member 8c that supports the master 8 so that the master 8 can be fed out in the master transport direction X1, a thermal head 11 that heats the master 8 that has been fed out according to image information, and the master 8 on the thermal head 11. A platen roller 9 that conveys the master 8 while rotating the master 8 downstream in the master conveying direction X1 while pressing, and a master 8 that has been conveyed by the platen roller 9 while applying appropriate tension further downstream in the master conveying direction X1. A pair of transport rollers 13 to be transported, a cutter 12 disposed between the platen roller 9 and the pair of transport rollers 13 for cutting the pre-made master 8 or the unmade master 8 into a predetermined length, the platen roller 9 and A master guide plate 14 that guides the leading end of the master 8 conveyed by the conveying roller pair 13 to the clamper 7 that is expanded on the plate cylinder 1. Comprising the door.

  The master 8 is wound around a roll core 8b to form a master roll 8a. In the master roll 8a, the roll cores 8b on both ends are rotatably supported by the master support member 8c in a counterclockwise direction, and are detachable from the master support member 8c. The master support members 8c on both ends are attached and fixed to plate making side plate pairs (not shown) disposed on the left and right sides of the plate making portion 15 along the master transport direction X1. Therefore, the master 8 is supported by the master support member 8c so that it can be fed out from the master roll 8a in the master transport direction X1.

  The master 8 has a laminated structure in which, for example, a thermoplastic resin film having a thickness of 1 to 5 μm and a porous support made of synthetic fiber or the like are bonded together. The master is not limited to this. For example, a master made by bonding a porous support and a thermoplastic resin film made of Japanese paper fiber or a mixture of Japanese paper fiber and synthetic fiber, or a so-called substantially thermoplastic resin film. A master or the like consisting only of the above is also used.

  The thermal head 11 is provided so as to extend in parallel with the platen roller shaft of the platen roller 9 on the front side and the back side of the paper surface of FIG. 1 (this direction is referred to as a main scanning direction), and is a cam (not shown). The platen roller 9 can be contacted and separated via the master 8 by a contact / separation mechanism including a spring member and the like. The thermal head 11 is urged by the spring member so as to contact the platen roller 9.

  In the main scanning direction of the thermal head 11, a large number of heat generating elements (not shown) are disposed at portions that contact the platen roller 9 via the master 8. The thermal head 11 passes through an A / D conversion unit and an image signal processing unit, both not shown, and the heat generation based on a digital image signal processed and sent out by a plate making control device and a thermal head drive circuit (both not shown). By selectively heating the element, it has a well-known function as a plate making means for selectively heating, melting, punching and making the master 8.

  The platen roller 9 is formed integrally with the platen roller shaft. The platen roller 9 is rotatable clockwise because both end portions of the platen roller shaft are rotatably supported by the plate-making side plate pair. The platen roller 9 is connected to a master transport motor 10 via a rotation transmission member (not shown) such as a timing belt or a gear, and is thereby driven to rotate clockwise. The master transport motor 10 is composed of, for example, a stepping motor. As described above, when the platen roller 9 is driven to rotate clockwise by the master transport motor 10, the master 8 is pulled out from the master roll 8a.

  The conveying roller pair 13 is provided with an appropriate pressing force applied by an urging means such as a spring and pressed against each other, and both end portions of each roller shaft are rotatably supported by the plate making side plate pair. Thus, they can rotate in opposite directions. The conveyance roller pair 13 is set to rotate at a circumferential speed (conveyance speed) slightly faster than the circumferential speed (conveyance speed) of the platen roller 9 by the rotation transmission member including the master conveyance motor 10. Appropriate front tension is applied to the master 8 while sliding between the two.

  The cutter 12 is a known guillotine type that includes a fixed blade 12b and a movable blade 12a. The cutter 12 is not limited to the guillotine type, and may be a rotary blade moving type in which the movable blade moves while rotating in the master width direction orthogonal to the master transport direction X1.

  The plate making unit 15 includes components that constitute plate feeding means capable of transporting and winding the master-made master 8 to the plate cylinder 1. As plate feeding means, a platen roller 9 of the plate making section 15, a conveying roller pair 13, a master guide plate 14, a clamper 7 of the plate cylinder 1 described later, an opening / closing device and a plate as an opening / closing means (not shown) for driving the clamper 7 to open and close. A main motor 20 that rotationally drives the body 1 is included.

  In the plate making section 15 shown in FIG. 14, the control target drive means of the plate making section 15 including the thermal head 11 driven by a thermal head drive circuit (not shown) and the master transport motor 10 is collectively referred to as the plate making drive means 124. .

  The plate cylinder 1 has a two-layer structure of a porous and cylindrical support cylinder and a mesh screen (not shown) made of a resin or metal mesh wound around a plurality of layers so as to cover the outer periphery of the support cylinder. Consists of. The plate cylinder 1 is provided with a printable aperture 1a (hereinafter sometimes referred to as “image forming region”) in which a large number of ink-permeable apertures are formed, a clamper 7 and the like, and cannot be printed. A non-opening portion (hereinafter sometimes referred to as “non-image forming region”) is formed along the rotation direction of the plate cylinder 1 indicated by an arrow in FIG. The image forming area includes a first image area 1A (hereinafter referred to as “front surface area 1A”), an intermediate area 1C, and a second image area 1B (hereinafter referred to as “back surface area 1B”) in the plate cylinder 1 in FIG. ”) At least.

  The plate cylinder 1 is wound and fixed around an outer peripheral portion of an end plate flange (not shown), and is rotatably supported around a support shaft 5 that also serves as an ink pipe 5 described later. In terms of the embodiment, the size of the plate cylinder 1 is, for example, a size that can be printed on A3 size paper 36 at the maximum during single-sided printing to obtain an A3 size printed matter, that is, A3 size 1 The plate master 8 has a size capable of being wound, its outer diameter is 180 mm (the outer peripheral length of the plate cylinder 1 is about 565 mm), and its width direction (rotation center axis direction) is 350 mm. Is set.

  The plate cylinder 1 is connected to a main motor 20 as a plate cylinder driving unit via a drive transmission unit such as a gear or a belt (not shown). It is rotationally driven (clockwise). On the output shaft of the main motor 20, an optical rotary encoder (not shown) and a plate cylinder sensor 350 (which sandwiches this and generates a pulse by the cooperative action of the rotary encoder 351 (shown in FIG. 15) are provided. 15) is provided. The plate cylinder sensor 350 includes a transmissive optical sensor (hereinafter simply referred to as a “transmissive optical sensor”) having a light emitting unit and a light receiving unit, and controls and rotates the rotational speed (printing speed) of the plate cylinder 1. It is used for position determination.

  Inside the plate cylinder 1 is rotatably supported by a side plate (not shown), and the rotational driving force of the main motor 20 is transmitted by a drive transmission means such as a gear (not shown) so as to be synchronized with the rotation of the plate cylinder 1. An ink roller 2 that is driven to rotate in the direction of the middle arrow (clockwise) and contacts the inner peripheral surface of the plate cylinder 1 to supply ink, and an ink roller 2 that is arranged in parallel with the ink roller 2 with a slight gap therebetween. A doctor roller 3 for forming an ink reservoir 4 having a wedge-shaped cross section and an ink pipe 5 for supplying ink to the ink reservoir 4 are disposed between the two. The ink roller 2, the doctor roller 3, and the ink pipe 5 constitute a single ink supply means for supplying ink to the divided master-making master 8X and the master-making master 8Y on the plate cylinder 1.

  The ink in the ink reservoir 4 is sucked by an ink pump (not shown) from an ink pack (not shown) provided outside the plate cylinder 1, supplied from the supply hole of the ink pipe 5, and kneaded. The ink in the ink reservoir 4 is supplied as a thin film on the outer peripheral surface of the ink roller 2 while being measured by the doctor roller 3, and the outer peripheral surface of the ink roller 2 is in contact with the peripheral surface of the support cylinder in the plate cylinder 1. Is supplied to the opening 1a portion of the plate cylinder 1.

  A portion of the plate cylinder 1 on the outer peripheral surface of the non-opening portion includes a ferromagnetic stage 6 provided along one bus bar of the plate cylinder 1 and clampers provided on both side ends of the stage 6. A clamper 7 having a rubber magnet that is rotatably attached to the shaft and can be opened and closed with respect to the flat surface of the stage 6 is provided. The clamper 7 is opened and closed at a predetermined position by an opening / closing device (not shown) provided on the main body frame side.

  The plate cylinder 1 is stopped in a state in which the clamper 7 is positioned almost directly as shown in FIG. The plate cylinder 1 is configured as a plate cylinder unit integrally formed with an ink pack mounting table (not shown) on which the ink pack is detachably mounted, the ink pump, and the like. The ink pipe 5 is detachable from the main body frame in the axial direction.

  In FIG. 1, on the end plate flange of the plate cylinder 1 on the back side of the paper surface and on the main body frame side in the vicinity of the end plate flange, the rotation position of the plate cylinder 1 is detected as shown in FIG. Components for providing start-up / trigger information to the sheet feeding motor 37 and the registration motor 41 shown in FIGS. 1 and 11 are arranged. That is, on the outer wall of the end plate flange on the back side in the plate cylinder 1, the sheet feeding start light shielding plate 121 and the resist start light shielding plate 122 are spaced apart from each other on the same circumference of the plate cylinder 1. Each is attached to a predetermined position.

  On the other hand, on the main body frame side in the vicinity of the respective light shielding plates 121 and 122, these are opposed to the same circumference of the plate cylinder 1 to which the paper feeding start light shielding plate 121 and the resist start light shielding plate 122 are attached. A sheet feeding registration sensor 120 is attached in a sandwiching manner. The paper feed registration sensor 120 is a transmissive optical sensor.

  The home position (initial position) of the plate cylinder 1 is a position at which the clamper 7 is positioned almost directly above and receives and holds the leading end portions of the divided plate-making master 8X and the plate-making master 8Y conveyed from the plate-making section 15. It is set at the same position as a certain plate supply standby position. A light shielding plate for home position (not shown) for detecting the home position of the plate cylinder 1 is attached to a predetermined position of the outer wall of the end plate flange on the back side of the plate cylinder 1. A home position sensor (not shown) is attached to the main body frame side in the vicinity of the home position light shielding plate so as to face the home position light shielding plate of the plate cylinder 1 and sandwich it. The home position sensor is a transmissive optical sensor.

  In FIG. 14, the plate cylinder sensor 350, the paper feed registration sensor 120, and the home position sensor are collectively referred to as a plate cylinder position detection sensor 29 as drum rotation angle information detection means for detecting the rotation position of the plate cylinder 1.

  A single press roller 21 is disposed near the lower part of the outer peripheral surface of the plate cylinder 1 facing the ink roller 2. The press roller 21 is configured by integrally fixing an elastic body to the press roller shaft 21 a, and is provided so as to extend in the axial direction of the plate cylinder 1. The press roller 21 is formed so that its lateral width is substantially the same as the lateral width of the plate cylinder 1. As shown in FIGS. 2 to 4, the press roller 21 has a pair of printing arms 22 as pressing means support members disposed on the front side and the back side of the sheet via both ends of the press roller shaft 21 a. (The front side of the paper is omitted) and is supported rotatably.

  Each printing pressure arm 22 is arranged with substantially the same shape and the same phase on the front side and the back side of the drawing. Each printing pressure arm 22 is integrated with an arm shaft 22a attached and fixed to a portion near the bent portion and a connection reinforcing member (not shown). A notch 22b that selectively engages with a locking claw 60a of a locking member 60 described later is formed at the lower end of the printing pressure arm 22 shown in the figure. The arm shaft 22a is rotatable by a predetermined angle via a bearing (not shown) between a pair of housing side plates (not shown) fixed on the main body frame side (see the housing side plate pairs 130a and 130b in FIG. 7). It is supported by.

  The press roller 21 is formed of, for example, nitrile rubber (NBR), which is an elastic body having oil resistance, and at least the outer peripheral surface of the rubber is a film having a fine uneven surface treatment, for example, For example, glass beads as glassy fine particles, which are the same as those used for preventing smearing of printed matter in an offset printing machine or the like, are uniformly coated or adhered. Not only glassy fine particles but also ceramic fine particles may be used. As a result, when the outer peripheral surface of the plate cylinder 1 or the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1 comes into contact, or as described later with reference to FIG. 4, the printed image of the surface-printed paper 36a. Swelling and ink stain due to contact with the ink on the surface side are minimized.

  The press roller 21 is not applied to the divided plate-making master 8X or the plate-making master 8Y on the plate cylinder 1 via the printing pressure range varying means 28, the locking means 64 and the printing pressure arms 22 shown in FIGS. The printing position shown in FIGS. 3 and 4 that presses the printing paper 36 or the surface-printed paper 36a and the non-printing position including the initial position shown in FIGS. 1 and 2 away from the printing position are configured to be displaceable. Has been. As described above, the pair of printing arms 22 as the pressing means support members support the press roller 21 as the pressing means so as to be rotatable, and make the press roller 21 contactable / separable with respect to the plate cylinder 1. It is configured to be displaceable. The printing pressure range varying means 28 may also be called a press roller contacting / separating mechanism as pressing means contacting / separating means.

  In FIG. 2, reference numeral 54 denotes a press roller rotation driving unit as a pressing unit driving unit that rotationally drives the press roller 21. The press roller rotation drive means 54 is a press roller drive as a drive means for driving the press roller 21 to rotate in the direction opposite to the rotation direction of the plate cylinder 1 (counterclockwise) at substantially the same peripheral speed as that of the plate cylinder 1. The motor 55 and the driving force transmitting means for transmitting the rotational driving force of the press roller driving motor 55 to the press roller 21 are mainly configured. The press roller drive motor 55 is attached and fixed to the outer wall of the printing pressure arm 22 on the back side in FIG.

  As shown in FIG. 2, the driving force transmitting means includes a toothed driving pulley 56 fixed to the output shaft 55a of the press roller driving motor 55, and a press roller protruding further to the back side of the paper surface of the printing pressure arm 22. A toothed driven pulley 57 fixed to the shaft 21a and a toothed endless belt 58 stretched between the driving pulley 56 and the driven pulley 57 are provided.

  The press roller 21 is a press roller driving motor in accordance with the timing when the unprinted paper 36, the front surface printed paper 36a, or the single-side printed paper 36c is pressed against the divided master making master 8X or the master making master 8Y on the plate cylinder 1. 55 is rotationally driven. The operation of the press roller drive motor 55 is controlled by the control device 100 shown in FIG. Control of the rotational speed of the press roller drive motor 55 via the driving force transmission means is performed so that the peripheral speed of the press roller 21 is substantially the same as the peripheral speed of the plate cylinder 1 as described above. According to the example of the present embodiment, the press roller 21 is rotationally driven by the press roller driving motor 55 at a peripheral speed that is substantially the same as the peripheral speed of the plate cylinder 1, so that it is possible to obtain a good printed matter with no print image positional deviation. it can.

  As shown in FIGS. 1 to 6, a refeed conveyance device 104, a refeed stopper unit 70, a roller guide plate 50, and the like constituting the refeed unit 45 are disposed between the printing pressure arms 22. ing. The refeed stopper means 70 includes a guide plate 70a, a rectangular plate-like stopper 70b that moves up and down through the guide plate 70a, and a solenoid 70c that drives the stopper 70b to release the contact between the paper and the stopper. . The stopper 70b can take a projecting position guided by guide means (not shown) and projecting from the guide plate 70a, and a retracted position in which the upper end of the guide plate 70a is lowered to the upper surface level. When the solenoid 70c is turned on, the stopper 70b is stopped. 70b is in a retracted position. When the solenoid is turned off, the stopper 70b is in the protruding state as described above. In the protruding position, the leading edge of the sheet is stopped from moving by the stopper 70b. In the retracted position, the stopper 70b does not hinder the progress of the sheet, so that the sheet is conveyed toward the press roller 21 by driving the conveying belt 108.

  In this manner, the refeed unit 45 temporarily stops the surface-printed paper 36a on which the print image is formed by the printing unit 16 and transports it toward the press roller 21 at a predetermined time. Re-feed conveyance device 104 as a re-feed conveyance device that can be activated, and the front end of the front-side printed paper 36a conveyed by the re-feed conveyance device 104 ("rear end" with respect to the paper conveyance direction X) However, since it is “front end” or “front end” with respect to the transport direction of the front surface printed paper 36a, it is referred to as “to be temporarily stopped” before positioning to the press roller 21 for positioning. A re-feed stopper means 70 as a re-feed stop means, and a nip provided on the right side of the press roller 21 in the vicinity of the outer peripheral surface of the press roller 21 to form the surface-printed paper 36 a in the printing unit 16. Is mainly composed of the roller guide plate 50 serving as a refeed guide means for guiding the 16a.

  As shown in FIGS. 1 to 6, the sheet refeeding / conveying device 104 extends below the trajectory of the reciprocating movement of the movement guide 81. As shown in detail in FIGS. 2 to 6, the refeed conveyance device 104 is integrally provided on the drive shaft 107 a and a refeed housing 110 that rotatably supports the drive shaft 107 a and the driven shaft 106 a. A conveyance roller rear 107 as a driving roller, a conveyance roller front 106 as a driven roller provided integrally with a driven shaft 106a disposed upstream of the driving shaft 107a in the paper conveyance direction X, and a conveyance roller rear 107 A plurality of air suction holes 108a are formed as endless belts that are wound and stretched between the front of the transport rollers 106 and hold and transport the surface-printed paper 36a delivered from the moving guide 81. The conveying belt 108 is connected to the driving shaft 107a via a driving force transmission means such as a gear or a belt, and the conveying belt 108 is connected via the rotation driving of the conveying roller 107. A belt driving motor (conveyance motor) 105 serving as a belt driving means for driving in rotation and a surface printed sheet 36a delivered from the moving guide 81 are attracted to the upper surface side of the conveying belt 108 by sucking air from a large number of holes 108a. It is mainly composed of a suction fan 109 for holding.

  The re-feeding casing 110 is formed such that its upper surface is opened and its width is slightly smaller than the interval between the printing pressure arms 22, and has a substantially U-shaped side section. The bottom wall of the refeed housing 110 is formed with a number of holes or slits (not shown) for allowing the air flow from the suction fan 109 to escape downward. The refeed housing 110 has bearings (not shown) on both the upstream and downstream sides in the paper transport direction, and these bearings rotatably support the drive shaft 107a and the driven shaft 106a, respectively. Yes. Both ends of the drive shaft 107a penetrate both side surfaces of the refeed housing 110, and both ends of the penetrated drive shaft 107a can be rotated by a bearing member (not shown) provided on the main body frame. It is supported.

  A drive gear (not shown) is attached to one end of the drive shaft 107a (the back side of the paper in FIGS. 2 to 5), and the drive shaft 107a is rotated by a belt drive motor 105 connected via the drive gear. Driven. The conveyor belt 108 is intermittently rotated clockwise at a specific timing according to the type of paper as will be described later by the operation of the belt drive motor 105 based on the command signal from the control device 100 shown in FIG. . The belt drive motor 105 is a stepping motor, and is fixed to the main body frame side. The driven shaft 106 a is configured such that both ends thereof do not penetrate both side surfaces of the refeed housing 110.

  Pins 111 are respectively protruded and fixed to the outer side walls of the upstream end of the paper feeding direction X in the paper refeeding housing 110, and each pin 111 is formed on each printing pressure arm 22. Each of the clearance holes is loosely fitted. As a result, the refeed casing 110 is driven by the drive shaft 107a as the printing pressure arm 22 swings when the press roller 21 is brought into contact with or separated from the plate cylinder 1 by the printing pressure range varying means 28 described later. The paper refeeding / conveying device 104 on the side where the pin 111 is arranged can be swung.

  The conveying roller rear 107 and the conveying roller front 106 are divided into skewers, are formed of, for example, a toothed roller, and are formed of a high friction material. Incidentally, it is desirable to form the post-conveyance roller 107 and the pre-conveyance roller 106 with a high friction material having oil resistance (ink corrosion resistance) such as nitrile rubber (NBR) or an appropriate resin. The conveyor belt 108 is formed of, for example, a toothed belt, and a plurality of belts are wound and stretched between a conveyor roller rear 107 and a conveyor roller front 106 which are divided into skewers. Incidentally, the conveyor belt 108 is desirably formed of, for example, nitrile rubber (NBR) which is an elastic body having oil resistance (ink corrosion resistance).

  The suction fan 109 is rotated so that the surface-printed paper 36 a delivered from the moving guide 81 is attracted to the upper surface side of the transport belt 108 by sucking air from the many holes 108 a of the transport belt 108. A fan drive motor is incorporated as a fan drive means for driving. Hereinafter, the fan drive motor is simply referred to as “suction fan 109”.

  The stopper 70b temporarily stops the front end of the front surface printed paper 36a at a position where it can be transferred to the press roller 21, and also has a function of positioning the front end of the front surface printed paper 36a and correcting skew. The stopper 70b includes a stopper surface 53a for abutting and positioning the front end of the front surface printed paper 36a. The guide plate 70 a is fixed to the paper re-feeding casing 110, whereby the paper re-feed stopper means 70 is oscillated and displaced together with the paper re-feed conveyance device 104 and the press roller 21.

  As shown in FIG. 2 to FIG. 4 and FIG. 6, at the upstream end portion of the guide plate 70 a in the paper transport direction X, the front surface printed paper detection that detects that the front end of the front surface printed paper 36 a is close to the stopper 70 b. A refeed sensor 52 is provided as a means. The re-feed sensor 52 includes a reflection-type optical sensor, and includes a front end (front right side of the front surface printed paper 36a illustrated in FIG. 4) and a rear end (left end of the front surface printed paper 36a illustrated in FIG. 4). ).

  The roller guide plate 50 has a function of guiding the surface-printed paper 36a to be conveyed toward the plate cylinder 1 by bringing it into contact with the outer peripheral surface of the press roller 21. The roller guide plate 50 has a curved partial cylindrical shape centered on the press roller shaft 21a in order to guide the surface-printed paper 36a along the outer peripheral surface of the press roller 21. The roller guide plate 50 and the outer peripheral surface of the press roller 21 have a predetermined shape. Are fixed between the printing pressure arms 22.

  The guide surface side of the surface-printed paper 36a on the roller guide plate 50 has a low coefficient of friction with respect to the surface-printed paper 36a and a smooth coating film having ink repellency and oil resistance such as polytetrafluoroethylene resin. It is coated.

  In FIG. 14, the control target drive means of the refeed means 45 includes a solenoid 70c, a belt drive motor 105, a suction fan 109, and the like. Various detection means of the paper refeed means 45 include a paper refeed sensor 52 and the like.

  Next, the configuration around the printing pressure range varying means 28 that determines the printing pressure range of the press roller 21 will be briefly described. In the present embodiment, as shown in FIGS. 1 and 9, a first printing pressure range pattern that applies printing pressure only to the surface region 1A corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is used. And a printing pressure range pattern as a second printing pressure range pattern that applies printing pressure only to the back surface area 1B corresponding to the back plate making image 8B in the divided plate-making master 8X on the plate cylinder 1. II and a printing pressure range as a third printing pressure range pattern that applies a printing pressure from the front surface area 1A to the back surface area 1B corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1. One of at least three printing pressure range patterns with the pattern III can be selectively switched. A part of the mechanism relating to the printing pressure range varying means 28 for selectively switching one of these three printing pressure range patterns is shown in FIGS. The printing pressure range varying means 28 also has a configuration / function for displacing the press roller 21 between the printing position and the non-printing position.

  The printing pressure range variable means 28 includes a multi-stage cam (43), a step cam (49), and a stepping motor that rotationally drives the step cam (49) shown in FIGS. (52) etc. It is the structure similar to the press roller contacting / separating mechanism (55). Incidentally, in FIG. 2 and FIG. 3, the printing pressure range varying means 28 is composed of components such as a multi-stage cam (43), a step cam (49), and a stepping motor (52) that constitute the press roller contact / separation mechanism (55). A part thereof is represented by a sign obtained by adding a numerical value “200” to the sign of the above, and the arm shaft 22a, the printing pressure arm pair 22, the pair of cam followers 241, the pair of printing pressure springs 242, and the printing pressure cam shaft. 244, a pair of multistage cams 243, and the like. The stepping motor 252 is shown only in the printing pressure range variable means 28 shown in FIG.

  As shown in FIGS. 2 and 3, each of the constituent elements constituting the printing pressure range varying means 28 basically applies a uniform pressing force of the press roller 21 to the outer peripheral surface of the plate cylinder 1. Since the press roller 21 is disposed on the front side and the back side of the paper as viewed from FIG. 1 (the front side of the paper is omitted), the components on the back side of the paper will be described as a representative. Therefore, the description on the front side of the sheet is omitted. If the printing pressure range variable means 28 does not need the advantages as described above, the constituent elements of the printing pressure range variable means 28 are, for example, the back of the paper surface of FIGS. Of course, it may be arranged only on the side.

  As shown in FIGS. 2 and 3, a cam follower 241 is pivotally mounted on the outer wall at the center of the printing pressure arm 22 facing the inside of the printing pressure arm 22 on which the press roller 21 is supported. Is held. The cam follower 241 is configured by a rolling bearing so that the cam follower 241 can contact the multistage cam 243 with reduced frictional resistance.

  One end of a printing spring 242 (tensile spring) that constantly urges the press roller 21 in a direction in which it presses against the outer peripheral surface of the plate cylinder 1 is locked to the other end of the printing pressure arm 22. The other end is locked to the housing side plate side. By this printing pressure spring 242, the other end side of the printing pressure arm 22 is swung and urged clockwise around the arm shaft 22 a, and the press roller 21 is urged in a direction in which it is pressed against the outer peripheral surface of the plate cylinder 1. ing. A notch 22b that can be engaged with the locking claw 60a of the locking member 60 is integrally formed at the other end of the printing pressure arm 22, and can be engaged with and disengaged from the locking member 60.

  On the other hand, a printing cam shaft 244 to which a pair of multi-stage cams 243 that rotate in synchronization with the rotation of the plate cylinder 1 is fixed is rotatably supported on each casing side plate in the vicinity of each cam follower 241. The multistage cam 243 is composed of, for example, a plate cam in which a small diameter portion (concave portion) and a large diameter portion (convex portion) are formed.

  A belt pulley or gear (not shown) is fixed to the printing cam shaft 244, and is connected to the main motor 20 via a drive transmission means such as a belt or gear (not shown). The plate cylinder 1 rotates in synchronization with the rotation of the plate cylinder 1. The cam follower 241 is urged by the above-described printing pressure spring 242 so as to always come into contact with the multistage cam 243. Therefore, the cam driving means for rotationally driving the multistage cam 243 is mainly composed of the main motor 20.

  Each multistage cam 243 has three cam plates 243A, 243B, and 243C, which are fixed to a printing pressure cam shaft 244 that can move a predetermined amount in the axial direction at an appropriate interval, and are designated as necessary. Any one of the cams selected is selected and moved to a position facing the cam follower 243. The cam plates 243A, 243B, and 243C are arranged in the order of the cam plate 243B, the cam plate 243A, and the cam plate 243C from the front side of the sheet of FIG. 2 and FIG. Each of the cam plates 243A, 243B, 243C has a small diameter portion (concave portion or base portion) that is a disc concentric with the cam shaft 244 and a large diameter portion (convex portion) having the same protruding amount.

  The multistage cam 243 is a camshaft 244, that is, a drive gear (45) attached to the camshaft (44) shown in FIG. The rotational force from the plate cylinder driving means (121), that is, the main motor 20, is transmitted through the transmission gear (47) attached to the shaft (46), and is driven to rotate clockwise in FIG.

  The press roller 21 has a peripheral surface separated from the outer peripheral surface of the plate cylinder 1 when the large diameter portion of any one of the cam plates 243A, 243B, 243C contacts the cam follower 241 as shown in FIGS. FIG. 3 and FIG. 4 occupy the printing position and the peripheral surface thereof is pressed against the outer peripheral surface of the plate cylinder 1 by the biasing force of the printing spring 242 when the contact between the large diameter portion and the cam follower 241 is released. Occupies the printing position. Each of the cam plates 243A, 243B, and 243C is configured so that the small diameter portion (base portion) and the cam follower 241 do not come into contact with each other when the press roller 21 occupies the printing position.

  The shape of the large diameter portion of each cam plate 243A, 243B, 243C is such that the contact range between the press roller 21 and the plate cylinder 1 includes the surface region 1A, the intermediate region 1C, and the back surface region 1B shown in FIG. The cam plate 243B has the same range as the surface region 1A (see the printing pressure range pattern I shown in FIG. 9) so that all the ranges are combined (see the printing pressure range pattern III shown in FIG. 9). The cam plate 243C is formed to have the same range as that of the back surface region 1B (see the printing pressure range pattern II shown in FIG. 9).

  As shown in FIGS. 2 and 3, the locking means 64 is for holding the press roller 21 in the non-printing position shown in FIGS. The locking means 64 is mainly composed of a locking member 60, a support shaft 61, a solenoid 62, and a tension spring 63. The locking means 64 is disposed on the back side of the page.

  The locking member 60 is swingably supported around a support shaft 61 planted on the casing side plate on the back side of the paper surface, and one end of the locking member 60 is selected with the notch 22b of the printing pressure arm 22 described above. An engaging claw 60a that engages with each other is formed. The other end of the locking member 60 is locked with one end of a tension spring 63 that urges the locking claw 60a to always engage with the notch 22b of the printing pressure arm 22. The other end of the tension spring 63 is locked to the housing side plate side on the back side of the drawing. Further, the plunger of the solenoid 62 fixed to the housing side plate on the back side of the drawing via a bracket (not shown) as a stationary member on the side opposite to the arrangement portion of the tension spring 63 at the other end of the locking member 60. 62a is connected via a pin. The solenoid 62 uses a pull type.

  As described above, when the solenoid 62 is energized and the solenoid 62 is turned on, the printing pressure range variable means 28 is operated, and the press roller 21 occupies the printing position through the operation described later. As a result, the press roller 21 continuously presses the paper 36 while rotating it on the divided master-making master 8X or the master-making master 8Y on the plate cylinder 1. When the energization of the solenoid 62 is cut off and the solenoid 62 is turned off, the printing pressure range variable means 28 is deactivated, and the press roller 21 is separated from the printing position through the operation described later. 2 occupies the non-printing position (initial position).

  The solenoid 62 is on / off controlled by a control device 100 described later. By the on / off switching control of the solenoid 62 by the control device 100, the state is selectively switched between a state in which the printing pressure arm 22 is held and a state in which the holding is released. As will be described later, the solenoid 62 is turned on when the cam follower 241 is in contact with the large diameter portion of the multistage cam 243 (see FIG. 2).

  FIG. 9 is an expanded view of the printing pressure range of the press roller 21 for easy understanding. In FIG. 9, an area portion of the front plate-making image 8A and an area portion of the back-side plate-making image 8B are formed on the divided plate-making master 8X wound around the opening portion 1a on the plate cylinder 1 (not shown). In addition, there is an unfinished blank intermediate unfinished area 8C between them. Here, the leading side of the divided pre-printed master 8X, which is also referred to as the leading edge blank portion sandwiched and fixed by the clamper 7 of the plate cylinder 1 (not shown), is the left end side.

  The printing pressure range pattern III for normal printing including single-sided printing is performed by applying printing pressure from the region portion of the front plate-making image 8A to the region portion of the back-side plate-making image 8B through the intermediate non-plate-making region 8C. The cam plate 243A is operated by operating the printing pressure range varying means 28 according to a command from the control device 100 shown in FIG. 14 so that the sheet 36 is continuously pressed against the single-side plate-making image 8YA of the plate-making master 8Y. Is selected, and the cam plate 243A is rotationally driven so that the small diameter portion of the cam plate 243A faces the cam follower 241.

  At the time of front side printing, the printing pressure range variable means 28 is operated in accordance with a command from the control device 100 so as to be printed corresponding to the area portion of the front plate-making image 8A. Thus, the cam plate 243B is selected, and the cam plate 243B is rotationally driven so that the small diameter portion of the cam plate 243B faces the cam follower 241 and then the printing pressure is released in the intermediate unmade region 8C.

  At the time of printing on the back side, the printing pressure range pattern II is obtained, and the cam plate 243C is selected by the operation of the printing pressure range varying means 28 according to a command from the control device 100, so that the region portion of the first front plate-making image 8A is selected. Then, in order to release the printing pressure, the cam plate 243C is rotationally driven so that the large diameter portion of the cam plate 243C faces the cam follower 241 and then the small diameter portion of the cam plate 243C faces the cam follower 241.

  According to the present embodiment, since the printing pressure range variable means 28 is provided, the printing pressure on range is optimally set, and the printing pressure is turned on when there is no sheet and the press roller 21 It is possible to prevent a problem that the printed image is transferred to the outer peripheral surface and is stained with ink.

  The printing pressure range variable means 28 includes the multistage cam (43), the step cam (49), and the press roller contact / separation mechanism (55) shown in FIGS. 2 and 4 of JP-A-2003-200355 as described above. For example, an emergency pressing release means (79) shown in FIGS. 1 to 4 of JP-A-2003-237030 may be applied.

  As shown in FIG. 1, the paper discharge unit 19 is provided so as to be close to the outer peripheral surface of the plate cylinder 1, and a peeling claw 170 that peels the single-side printed paper 36 c from the plate-making master 8 </ b> Y on the plate cylinder 1. A separation fan 171 for blowing air between the front end portion of the single-side printed paper 36c separated by the nail 170 and the plate cylinder 1 to assist the separation action by the separation nail 170, and separation by the separation nail 170 and the separation fan 171. The paper discharge transport device 152 that transports the single-side printed paper 36c or the double-side printed paper 36b while sucking it, and the paper discharge tray 172 are mainly configured.

  The peeling claw 170 is provided in the vicinity of the downstream side of the nip portion 16 a formed when the press roller 21 is pressed against the outer peripheral surface of the plate cylinder 1. The peeling claw 170 is placed on the plate cylinder 1 in the vicinity of the outer peripheral surface of the plate cylinder 1 by a peeling claw displacing means (not shown) provided with a cam, a spring and the like that are driven to rotate in synchronization with the rotation of the plate cylinder 1. A separation position for forcibly separating the single-sided printed paper 36c from the pre-printed master 8Y, and a non-peeling position for avoiding contact with the clamper 7 arrangement portion protruding from the outer peripheral surface of the plate cylinder 1 apart from the separation position It is configured to be freely displaceable between. The peeling fan 171 has a built-in fan drive motor that rotationally drives the peeling fan.

  As shown in FIGS. 1 to 5, the paper discharge conveying device 152 is disposed below the peeling claw 170 and on the left side of the switching guide 46. The paper discharge roller rear 154 as a driving roller, a driven roller The sheet discharge roller front 156, a sheet discharge belt 158 which is an endless belt, a suction fan 159, and the like are provided. A plurality of post-discharge rollers 154 have a roller shape and are attached to a drive shaft 154a rotatably supported by the pair of casing side plates at a predetermined interval. A plurality of front discharge rollers 156 are also provided on the driven shaft 156a rotatably supported by the casing side plate pair at equal intervals with the rear 154 of each discharge roller. A paper discharge belt 158 is stretched around each paper discharge roller 154 and each paper discharge roller front 156 corresponding thereto.

  A drive gear (not shown) or a drive pulley (not shown) is attached to the drive shaft 154a (for example, the back side of the paper surface of FIGS. 1 to 5), and a motor gear (not shown) that meshes with the drive gear or between the drive pulley and the pulley (not shown). It is connected to a paper discharge belt drive motor 153 via a driving force transmission means such as a stretched belt. As a result, the paper discharge belt 158 is rotationally driven by the paper discharge belt drive motor 153 in the direction of the arrow (counterclockwise) shown in FIG.

  A suction fan 159 is disposed below the paper discharge belt 158. The suction fan 159 includes a fan drive motor that rotationally drives the suction fan. The paper discharge conveyance device 152 sucks the single-side printed paper 36c or the double-side printed paper 36b on each paper discharge belt 158 by the suction force of the suction fan 159, and the direction of the arrow in FIG. Transport to.

  In FIG. 14, the control target driving means of the paper discharge unit 19 including the fan drive motor of the separation fan 171, the paper discharge belt drive motor 153, and the fan drive motor of the suction fan 159 in the paper discharge unit 19 is collectively discharged. The driving means 127 is used.

  As shown in FIGS. 1 to 5, the switching guide 46 includes a nip portion 16 a serving as a print image forming portion in the printing portion 16 formed by pressing the press roller 21 against the plate cylinder 1, and paper discharge conveyance. It is disposed on a paper conveyance path to and from the device 152.

  The switching guide 46 is made of a plate material having substantially the same width as that of the plate cylinder 1 and the press roller 21, and its base end portion (downstream end portion in the paper transport direction X) is supported by the casing side plate so as to be rotatable by a predetermined angle. The free end portion (the upstream end portion in the paper transport direction X) is swingable about the shaft 46a. The outer peripheral surface of the switching guide 46 may be smoothly coated with a film having ink repellency and oil resistance, such as polytetrafluoroethylene resin.

  The switching guide 46 has a free end portion formed in an acute cross section when the solenoid 47 as the switching driving means shown in FIGS. 2 and 14 operates against the urging force of a tension spring as urging means (not shown). Are selectively positioned at a first displacement position indicated by a solid line and a second displacement position indicated by a two-dot chain line in FIG.

  The switching guide 46 is usually given a habit of swinging by the urging force of the tension spring at the first displacement position which is also the initial position shown in FIG. When the switching guide 46 occupies the first displacement position, the tip of the switching guide 46 comes close to the outer peripheral surface of the press roller 21 and does not interfere with the clamper 7 on the plate cylinder 1 and occupies the second displacement position. The tip of the plate cylinder 1 is placed close to the peripheral surface of the plate cylinder 1.

  The double-side printed paper 36b or the single-side printed paper 36c that has passed between the plate cylinder 1 and the press roller 21 is guided to the paper discharge unit 6 when the switching guide 46 occupies the first displacement position, The printed sheet 36a is delivered to the moving guide 81 while being guided by the switching guide 46 when the switching guide 46 occupies the second displacement position. The switching drive means for displacing the switching guide 46 between the first displacement position and the second displacement position is not limited to the combination of the solenoid 47 and the tension spring, and is driven by, for example, a stepping motor or a rotary solenoid. It may be.

  As shown in FIGS. 1 to 5, the movement guide 81 is disposed between the discharge conveyance device 152 and the switching guide 46 and the refeed conveyance device 104. As shown in FIGS. 3, 7 and 8, the moving guide 81 has a moving position P <b> 1 in which the leading end including the leading end of the front surface printed paper 36 a fed from the nip 16 a is a first position in the vicinity of the printing unit 16. 7 and FIG. 8, a sheet that opens the front end of the surface-printed sheet 36 a at the initial position P <b> 2 as the second position in the vicinity of the upstream side of the refeed unit 45 that is lower than the movement position P <b> 1. It has a function and configuration as a clamping means.

  The movement guide 81 is integrated with a clamping table 81f that clamps and places the front end of the surface-printed paper 36a, and a clamping table 81f that is downstream of the paper-printing direction Xa of the surface-printed paper 36a fed from the nip portion 16a. A pair of end fences 81d having a paper contact surface 81e that contacts the front end of the surface-printed paper 36a formed on the front and back sides of the paper surface of the clamping table 81f and integrated in the reciprocating direction. Four projections 81c as guided portions formed on the front surface, clamp claws 81b as clamping members that can be opened and closed with respect to a clamping base 81f that grips and clamps the front end portion of the surface-printed paper 36a, and clamp claws 81b A clamp shaft 81a that can be pivoted (rotated by a predetermined angle) for mounting and fixing the base end of the clamp, and a clamp shaft 81a for supporting the clamp shaft 81a so as to be rotatable by a predetermined angle. A pair of bearing brackets 81g shown only in FIG. 7 integrally attached to both side ends of the holding base 81f and the free end of the clamp claw 81b are pressed against the upper surface of the holding base 81f. It is mainly composed of a torsion coil spring (not shown) as urging means and a pair of upper and lower release levers 82 and 83 shown in FIG. 8 attached and fixed to the back side of the paper surface of the clamp shaft 81a. Yes.

  The movement guide 81 is formed in a substantially L-shaped cross section by a clamping table 81f and an end fence 81d. The four protrusions 81c are loosely fitted in guide grooves 88 formed in the case side plate pairs 130a and 130b shown in FIG. The clamp claw 81b is inclined with an acute rising angle with respect to the paper traveling direction Xa (conveying direction) of the surface-printed paper 36a fed from the nip portion 16a, and its base end is attached and fixed to the clamp shaft 81a. The free end is formed into an acute angle.

  In addition, the clamp claw 81b is made of metal or resin that extends and is fixed in the paper width direction Y of the clamp shaft 81a so as to clamp and grip the front end of the front surface printed paper 36a fed from the nip portion 16a. It consists of a thin plate-shaped member. A mounting portion 84 shown in FIG. 7 is integrally provided at a lower portion of the clamping table 81 f on the back side of the paper surface. The mounting portion 84 is fixed to a timing belt 89 that constitutes the moving means 87.

  The release lever upper 82 and the release lever lower 83 are formed of plate-like members. Note that the protrusion 81c is not limited to being formed integrally with the holding base 81f, but may be formed of a roller that can roll on the inner wall of the guide groove 88 with little frictional resistance.

  According to the movement guide 81 of the present embodiment, the surface printing is provided by including the clamp claw 81b inclined with an acute rising angle with respect to the paper traveling direction Xa of the surface printed paper 36a fed from the nip portion 16a. When a load or the like is applied in the direction in which the surface-printed paper 36a is removed during conveyance of the used paper 36a, the moment of increasing the clamping force (pressing force), that is, the moment for rotating the clamp claw 81b counterclockwise is generated. Therefore, the clamping force (pressing force) is increased and the sheet 36a can be prevented from coming off, and the clamping force as a biasing force of a torsion coil spring (not shown) can be set small, and it is not necessary to make it firmly and inexpensively. It has the advantage of being configurable.

  It should be noted that the portion of the moving guide 81 that contacts the surface-printed paper 36a is formed of a metal material having an antistatic action or subjected to an evaporation process or a plating process having an antistatic action. Is more preferable.

  As shown in FIG. 7, the moving means 87 is disposed outside the casing side plate 130b on the back side of the paper, and has a function and configuration for reciprocating the moving guide 81 between the moving position P1 and the initial position P2. Have The moving means 87 is an arcuate guide formed so as to be inclined downward to the left so as to be substantially the same as the transport drop path in the paper traveling direction Xa of the surface-printed paper 36a and penetrate the housing side plate pair 130a, 130b. A groove 88, a toothed drive pulley 90 rotatably supported with a shaft 90a on a housing side plate 130b in the vicinity of the downstream end in the paper traveling direction Xa of the surface-printed paper 36a in the guide groove 88, and a guide groove 88, a toothed driven pulley 91 having a shaft 91a rotatably supported by a housing side plate 130b in the vicinity of the upstream end in the paper traveling direction Xa of the front surface printed paper 36a, a driving pulley 90 and a driven pulley 91; A timing belt 89 that is stretched and stretched between the housing and the housing side plate 130b with a shaft (not shown) so as to contact and apply tension to the timing belt 89. A plurality of tension rollers 95 supported movably, a drive gear 92 attached and fixed to the shaft 90a of the drive pulley 90, and a forward and reverse rotation attached and fixed to the casing side plate 130b near the shaft 90a of the drive pulley 90 A drive motor 94 as a possible drive means and a motor gear 93 that is attached and fixed to the output shaft 94a of the drive motor 94 and meshes with the drive gear 92 are mainly configured.

  The timing belt 89 is connected and fixed to the moving guide 81 via an attachment portion 84 formed integrally with the lower portion of the holding base 81 f of the moving guide 81. The drive motor 94 is composed of a stepping motor, for example. As described above, the driving motor 94 is the driving means of the moving means 87, the guide groove 88 is the guiding means of the moving means 87, and the timing belt 89, the driving pulley 90, the driven pulley 91, the driving gear 92, and the motor gear 93 are the driving motor 94. The driving force transmission means for transmitting the driving force to the movement guide 81 is configured.

  As shown in FIG. 3, FIG. 7, FIG. 8 and FIG. 8 in which the moving guide 81 clamps the front end of the surface-printed paper 36a through the driving force transmitting means by forward / reverse driving of the driving motor 94, as shown by the solid line in FIG. In the vicinity of the movement position P1 (first position) that is in the vicinity of the printing unit 16 and in the vicinity of the upstream side of the refeeding means 45 that is lower than the movement position P1 (near the upper part of the rear side of the conveyance roller 107 of the refeeding conveyance device 104) In order to selectively occupy the initial position or standby position (second position) indicated by a solid line in FIGS. 1 and 2 and a two-dot chain line in FIGS. Reciprocates. In the vicinity of the drive pulley 90, a home position sensor 85 is provided for detecting when the movement guide 81 occupies the second position, which is the home position P2 (initial position P2).

  As shown in FIG. 8, the release cam 98 and the torsion coil spring come into contact with the lower release lever 83 of the movement guide 81 when the movement guide 81 occupies the movement position P <b> 1 indicated by the solid line. The clamp claw 81b is swung clockwise (rotated by a predetermined angle) via the release lever lower 83 and the clamp shaft 81a against the urging force of the first position, and then once released, the movement guide 81 is moved from the movement position P1. When the movement starts toward the initial position P2 indicated by the chain line, the contact state with the lower release lever 83 is released, and the clamping claw 81b is swung counterclockwise by the biasing force of the torsion coil spring. Thus, it has a function as an operation timing control unit that operates so as to sandwich the leading end portion of the front surface printed paper 36a. As shown in FIG. 8, when the movement guide 81 occupies the initial position P2, the release pin 99 comes into contact with the release lever upper 82 of the movement guide 81, thereby resisting the biasing force of a torsion coil spring (not shown). It has a function as an operation timing control unit that operates to swing the clamp claw 81b clockwise via the release lever upper 82 and the clamp shaft 81a to open the front end of the surface-printed paper 36a.

  According to the present embodiment, the provision of the release cam 98 has the following advantages over the case where the release cam 98 is not provided. That is, for example, when the movement guide 81 occupies the movement position P1, the front end of the surface-printed paper 36a overcomes the urging force of a torsion coil spring (not shown) by the conveying force applied by the nip portion 16a, and the clamp pawl 81b is rotated clockwise. If the release cam 98 is removed so as to be inserted into the open portion (open portion between the tip of the clamp claw 81b and the upper surface of the clamping base 81f) by swinging, even if the twist Even if the biasing force of the coil spring is set according to a sheet with low stiffness, it is assumed that the leading end of the sheet is deformed or the sheet clamping force becomes unstable.

  On the other hand, according to the present embodiment, when the movement guide 81 occupies the movement position P1, the conveying force applied to the front end of the surface-printed paper 36a by the nip portion 16a by the action of the release cam 98 described above. Is smoothly inserted into the open portion (the open portion between the tip of the clamp claw 81b and the upper surface of the clamping table 81f), so that the surface-printed paper 36a is not affected by the strength of the paper. Can be securely clamped and clamped between the tip of the clamp claw 81b and the upper surface of the clamping table 81f, so that the surface-printed paper 36a can be kept in a stable state without meandering or skewing. It has the advantage that it can be transported well, and the printed image can be prevented from tilting during printing on the back side, and the resist from deteriorating due to tilting, etc. That.

  In addition, the opening time when the front end of the front-side printed paper 36a is clamped can be set to a certain extent by devising and adjusting the shape of the release cam. This can be performed without resistance, and the front-end printed sheet 36a can be favorably clamped at the front end.

  By the action and action of the release pin 99, when the movement guide 81 occupies the initial position P2, the front end portion of the surface-printed paper 36a held between the front end of the clamp claw 81b and the upper surface of the holding base 81f is released. The front surface printed paper 36a falls from the leading edge of the paper 36a onto the transport belt 108 of the refeed transport device 104, and is temporarily sucked and held on the transport belt 108 by the suction force of the suction fan 109 operating at this time. After that, it is conveyed by the rotational drive of the conveyor belt 108.

  Needless to say, the length of the transport belt 108 and the initial position P2 of the moving guide 81 are set to have optimum lengths depending on the length of the paper 36 used for duplex printing in the paper transport direction X.

  The plate removal unit 17 includes an upper plate removal member 160, a lower plate removal member 161, a plate removal box 162, a compression plate 163, and the like. The upper plate removal member 160 includes a driving roller 164, a driven roller 165, an endless belt 166, and the like. The drive roller 164 is driven to rotate clockwise in FIG. 1 by a plate discharge driving means 126 (see FIG. 14) including a plate discharge motor (not shown), so that the endless belt 166 moves in the arrow direction in FIG. The lower plate removal member 161 includes a driving roller 167, a driven roller 168, an endless belt 169, and the like.

  The driving roller 167 is driven to rotate in the clockwise direction in FIG. 1 by transmitting the driving force of the plate discharging motor that rotates the driving roller 164 by driving force transmitting means (not shown) such as a gear or a belt. The endless belt 169 moves in the direction of the arrow in FIG. Further, the lower plate discharging member 161 is movably provided by a moving unit (not shown) included in the plate discharging driving unit 126, and an endless belt 169 positioned on the outer peripheral surface of the driven roller 168 and the position shown in the figure is the plate cylinder 1. And a position that abuts on the outer peripheral surface.

The plate removal box 162 stores a used master therein and is detachably attached to the main body frame 130. The compression plate 163 is supported by the main body frame 130 so as to be movable up and down so that the used master carried by the upper plate removal member 160 and the lower plate removal member 161 is pushed into the plate release box 162. It is moved up and down by lifting means (not shown) including the lifting motor included.
In FIG. 14, the discharge target drive means 126 is collectively referred to as the control target drive means of the discharge plate section 17 including the discharge motor, the moving means, and the lifting motor of the discharge section 17.

  As shown in FIGS. 1, 10, and 11, the paper feed unit 30 contacts the paper feed tray 35 that can stack and lift up the paper 36 so that it can be raised and lowered, and the paper 36 on the paper feed tray 35. The sheet feeding roller 33 and the separating member 34 as sheet feeding means for separating and conveying the sheet 36 one by one toward the nip portion of the pair of registration rollers 31a and 31b (hereinafter referred to as “registration roller pair 31”). A sheet size detection sensor 117 serving as a sheet size detecting means for detecting the sheet size of the sheet 36, and a resist for feeding the sheet 36 at a timing described later between the outer peripheral surface of the plate cylinder 1 and the press roller 21. And a registration roller pair 31 as a means.

  On the paper feed path between the registration roller pair 31, the paper feed roller 33, and the separation member 34, a paper thickness sensor 79 is disposed as a paper type detection unit that detects the thickness of the paper 36. Although the paper thickness sensor 79 has been described in the present embodiment for the sake of convenience, the paper thickness sensor 79 is used in a modified example described later, and will be described below as not being provided in the present embodiment.

  The paper feed tray 35 is provided with a drive device (not shown) including a paper feed tray lifting / lowering motor (not shown) as a lifting / lowering means (not shown) for moving the paper feeding tray 35 up and down. A state in which the upper layer contacts the paper feed roller 33 with a predetermined pressing force (a pressing force capable of transporting the paper 36), that is, a state in which the paper 36 contacts with a pressing force within a range in which the paper 36 can be transported in conjunction with increase / decrease of the paper 36. It is lifted while holding.

  The paper feed tray 35 has a structure in which many paper types and paper sizes can be used, and the paper stacking capacity thereof is, for example, a paper size A3 (horizontal placement: the user stands in front of the paper in FIG. And a structure suitable for a stencil printing apparatus that can stack 500 sheets or more of paper 36 of paper size A4.

  In the paper feed tray 35, a pair of side fences (not shown) for positioning and aligning both side edges of the paper 36 according to the paper size is disposed so as to be movable in the paper width direction orthogonal to the paper transport direction X.

  In the vicinity of the lower portion of the paper feed tray 35, paper length size detection sensors 117a, 117b, and 117c (both are made of a reflective optical sensor) for detecting the length of the fed paper 36 and the fed paper 36 In the figure, a paper width size detection sensor (not shown) that detects the paper width on the front side and the back side of the paper surface (for example, a transmissive optical sensor that detects the paper width in conjunction with the movement of the pair of side fences in the paper width direction) Are provided). The paper length size detection sensors 117a, 117b, and 117c and the paper width size detection sensor detect the size of the fed paper 36. Hereinafter, these are collectively referred to as the paper size detection sensor 117.

  As shown in FIGS. 1 and 11, the paper feed roller 33 is formed integrally with the paper feed roller shaft 33a, and one end portion of the paper feed roller shaft 33a is rotatably supported by the casing side plate. Yes. The surface of the paper feed roller 33 is formed of at least a high friction resistance member such as rubber. A toothed paper feed roller pulley 39 is attached to one end of the paper feed roller shaft 33a.

  Between the paper feed roller shaft 33a and the paper feed roller pulley 39, a one-way clutch (not shown) for rotating the paper feed roller 33 so as to transport the paper 36 only in the paper transport direction X is disposed. Yes. The separation member 34 has a member called a separation pad that is made of rubber or resin having a high coefficient of friction with respect to the paper 36 and that can contact the paper feed roller 33. The separation pad is urged in a direction to be pressed against the paper feed roller 33 by a compression spring (not shown) as urging means.

  Below the paper feed roller pulley 39, a paper feed motor 37 as a paper feed driving means for rotationally driving the paper feed roller 33 is fixed to the casing side plate. The paper feed motor 37 is composed of, for example, a stepping motor, and a toothed paper feed motor pulley 38 is fixed to the output shaft thereof. A toothed paper feed motor belt 40 is stretched between the paper feed roller pulley 39 and the paper feed motor pulley 38. As a result, the paper feed roller 33 and the paper feed motor 37 are in a rotational driving force transmission relationship between the paper feed motor belt 40 and the one-way clutch.

  As shown in FIGS. 1 and 11, the registration roller upper 31a and the registration roller lower 31b are formed integrally with a registration roller shaft and a registration roller shaft 31c, respectively, and both ends of each registration roller shaft 31c are formed in the housing. The body side plate is rotatably supported.

  A toothed registration roller pulley 43 is attached to one end of the lower registration roller shaft 31c. The lower registration roller 31b is supported by the casing side plate through a registration roller shaft 31c so as not to move and to rotate freely. The upper registration roller 31a is provided so as to be able to contact and separate through registration roller contact / separation means (not shown) so as to come into contact with the lower registration roller 31b at a predetermined timing.

  A registration motor 41 as registration driving means for rotating the registration roller pair 31 is fixed to the casing side plate below the registration roller lower 31b. The registration motor 41 is composed of a stepping motor, for example, and a toothed registration motor pulley 42 is fixed to the output shaft thereof. Between the registration roller pulley 43 and the registration motor pulley 42, a toothed registration motor belt 44 is stretched. Thus, the lower registration roller 31 b and the registration motor 41 are in a rotational driving force transmission relationship via the registration motor belt 44.

  In FIG. 1, a sheet for detecting the leading edge and the trailing edge of the sheet 36 fed from the registration roller pair 31 is disposed on a sheet conveyance path XA from the plate cylinder 1 and the press roller 21 to the nip portion of the registration roller pair 31. A paper detection sensor 32 is provided as detection means. In the paper detection sensor 32, the paper 36 stays in the paper transport path XA on the upstream side of the arrangement position of the paper detection sensor 32 (position where the leading edge of the paper 36 can be detected) (jamming or the like occurs). It also has a function to detect.

The paper detection sensor 32 is a reflective optical sensor.
In FIG. 14, the control target drive means of the paper feed unit 30 including the paper feed tray lifting / lowering motor, the paper feed motor 37, and the registration motor 41 of the paper feed unit 30 is collectively referred to as a paper feed drive unit 125.

  As shown in FIG. 12, the image reading unit 18 includes the above-described document receiving base 134 on which a plurality of documents 133 are stacked, a contact glass 135 as a reading unit on which the document 133 is placed, and a document that conveys the document 133. A pair of transport rollers 136 and a document transport roller 137, guide plates 138 and 139 for guiding the transported document 133, a plurality of document transport belts 140 that transport the document 133 along the contact glass 135, and the read document 133 A document tray 141, a pressure plate 142 that supports each member except for the contact glass 135 and is provided so as to be able to contact / separate / open / close with respect to the contact glass 135, and scans and reads an image of the document 133 while illuminating it. Reflection mirrors 143 and 144 and a fluorescent lamp 145 for focusing the reflected light of the scanned and read image That a lens 146, and a image sensor 147 or the like provided with a CCD (charge coupled device) or the like for photoelectric conversion reflected light of the focused image.

  In the above configuration, the original 133 is placed on the contact glass 135 (reading unit) by the original receiving tray 134, the original conveying roller pair 136, the original conveying roller 137, the guide plates 138 and 139, the original conveying belt 140 and the original tray 141. An automatic document feeder (hereinafter referred to as “ADF”) 148 is configured as an automatic document feeder that feeds sheets one by one.

  A scanner device 132 serving as a document reading unit that reads an image of the document 133 on the contact glass 135 (reading unit) by the contact glass 135, the reflecting mirrors 143 and 144, the fluorescent lamp 145, the lens 146, and the image sensor 147, Each of the reflection mirrors 143 and 144, the fluorescent lamp 145, and the lens 146 constitutes a document scanning optical system.

  The document transport roller pair 136, the document transport roller 137, and the document transport belt 140 are driven by a document transport motor (not shown). The scanner device 132 is provided with a scanner motor (not shown) that drives the scanner device 132. The image sensor 147 performs photoelectric conversion corresponding to the received reflected light, and inputs an image signal obtained thereby to the A / D conversion unit.

  In the vicinity of the lower part of the contact glass 135, a document vertical size detection sensor 149a that detects the length of the document in the transport direction (left-right direction) in the view of the document 133 to be transported or the document not shown placed on the contact glass 135. 149b and the document 133 to be transported or the document lateral size detection sensor (not shown) that detects the length of the front side and the back side of the paper surface in the figure of the document (not shown) placed on the contact glass 135 or both. Sensor).

  The document vertical size detection sensors 149a and 149b and the document horizontal size detection sensor detect the sizes of the document 133 to be conveyed or the document (not shown) placed on the contact glass 135. These are hereinafter referred to as the document size detection sensor 149. Collectively.

  The original size detection sensors 149a and 149b of the original size detection sensor 149 and the original horizontal size detection sensor are both reflective optical sensors, and the outline and size of the original 133 and the original are determined by the difference in the amount of reflection on the contact glass 135. The presence or absence of 133 is detected.

A signal from the document size detection sensor 149 is input to the control device 100 described later.
Based on the signal from the document size detection sensor 149, the control device 100 determines and recognizes the document size (when it is the same size, it is also the size of the plate-making image to be made / formed on the master 8). A document detection sensor 131 that detects the document 133 remaining on the document tray 134 is disposed below the document tray 134. The document detection sensor 131 outputs a signal to the control device 100 when the document 133 on the document tray 134 is exhausted.

  In FIG. 14, the control target drive unit of the image reading unit 18 including the scanner motor and the document transport motor of the image reading unit 18 is collectively referred to as a reading drive unit 128. With reference to FIG. 13, a detailed configuration of the operation panel 173 that instructs the double-sided stencil printing apparatus 300 to perform a predetermined operation or the like will be described.

  The operation panel 173 is disposed in the vicinity of the image reading unit 18 shown in FIG. The operation panel 173 has a plate making start key 174, a printing start key 175, a test printing key 176, a continuous key 177, a clear / stop key 178, a numeric key 179, an enter key 180, a program key 181, a mode clear key 182 on the upper surface of the operation panel 173. A speed setting key 183, a printing speed display device 183A composed of LEDs (light emitting diodes), a four-direction key 184, a paper size setting key 185, a paper type setting key 186, a double-sided printing key 187, a single-sided printing key 188, and a 7-segment LED. A display device 189, a display device 190 including an LCD (liquid crystal display device), and the like are included.

  The plate-making start key 174 is pressed when the double-sided stencil printing apparatus 300 performs a plate-making operation. When the plate-making start key 174 is pressed, a plate-making operation is performed after a plate-discharging operation and a document reading operation are performed. The printing operation is performed and the double-sided stencil printing apparatus 300 enters a print standby state. The print start key 175 is pressed when the duplex stencil printing apparatus 300 performs a printing operation. When the duplex start stencil printing apparatus 300 enters a print standby state and various printing conditions are set, the print start key 175 is pressed. A printing operation for the set number of sheets is performed. The trial printing key 176 is pressed when causing the double-sided stencil printing apparatus 300 to perform trial printing, and only one sheet is printed by pressing the trial printing key 176 after various conditions are set.

  The clear / stop key 178 is pressed when the operation of the double-sided stencil printing apparatus 300 is stopped or when the number is cleared. The numeric keypad 179 is used for numerical input. The enter key 180 is pressed when setting a numerical value or the like at various settings, and the program key 181 is pressed when registering or calling an operation that is often performed, and the mode clear key 182 is used to clear various modes. Press to return to the initial state.

  The print speed setting key 183 is pressed when setting the print speed prior to the printing operation, and when it is desired to obtain a darker image or when the ambient temperature is low, the print speed is slow and a lighter image is desired. Or, when the ambient temperature is high, the printing speed is set fast.

  “Printing speed: 3rd speed” in which the printing speed of the printing speed display device 183A and the black color of the displayed central part are applied is a standard printing speed corresponding to the printing speed normally used, and the printing speed setting This is automatically set when the key 183 is not pressed.

  For example, the leftmost “printing speed: 1st speed” displayed as “slow” is the lowest printing speed of 16 sheets / min: 16 rpm, and the “printing speed: 2nd speed” next to the right is the printing speed. 60 sheets / min: 60 rpm, “standard printing speed: 3rd speed” is the printing speed is 90 sheets / min: 90 rpm, and “printing speed: 4th speed” next to the right is the printing speed is 105 sheets / min: 105 rpm. , “Printing speed: 5th speed” on the right side where “Hayaku” is displayed is set in correspondence with 120 sheets / min: 120 rpm, the highest printing speed. The printing speed display device 183A switches the printing speed to five levels from 1 to 5 by pressing the printing speed setting key 183 (speed up key and speed down key on the left and right) each time, and the set printing speed. Lights up.

  The four-way key 184 has an up key 184a, a down key 184b, a left key 184c, and a right key 184d. When adjusting the image position during image editing or when selecting numerical values or items at various settings, etc. Pressed. The paper size setting key 185 is pressed when an arbitrary paper size is input, and the paper size input with the paper size setting key 185 has priority over the paper size detected by the paper size detection sensor 117.

  A paper type setting key 186 is pressed when inputting a paper type prior to double-sided printing, and is classified into three types of “plain paper”, “thin paper”, and “thick paper”, which are also called standard papers in this embodiment, Further, any one of the paper types classified in detail corresponding to them is selected.

  In other words, in the present embodiment, the paper type setting key 186 can be used to select and set, for example, the characteristics of the paper thickness out of the paper types and the paper thickness out of its strength. This is based on the fact that the strength (so-called waist strength) tends to increase as the thickness of the paper increases.

  Thin paper includes renewal paper and high-quality 45 kg paper, and plain paper (standard paper) includes copying paper, medium-quality paper, high-quality 55 kg paper, recycled paper, stencil high-quality paper, and the like. Examples of cardboard include drawing paper, postcards, envelopes, high-quality 135 kg paper, and high-quality 180 kg paper.

  The double-sided printing key 187 is pressed before the plate making start key 174 is pressed when the double-sided stencil printing apparatus 300 performs the double-sided printing operation, and when the double-sided printing key 187 is pressed, the LED 187a disposed in the vicinity thereof lights up. Is displayed indicating that the duplex printing mode is set. Similarly to the double-sided printing key 187, the single-sided printing key 188 is pressed before pressing the plate making start key 184 when the double-sided stencil printing apparatus 300 performs a single-sided printing operation. The arranged LED 188a is turned on to indicate that the single-sided printing mode is set. In the double-sided stencil printing apparatus 300, the LED 188a is lit in the initial state after turning on the power switch (not shown), and the single-sided printing mode is set.

  The display device 189 mainly displays numbers such as the number of printed sheets. The display device 190 has a hierarchical display structure. By selecting and pressing selection setting keys 190a, 190b, 190c, and 190d provided below the display device 190, various modes such as scaling and image position adjustment are performed. Can be changed and set in each mode.

  Further, when the paper type setting key 186 is pressed on the display device 190, the paper type to be selected and set is displayed, or the double-sided stencil printing device 300 such as “can be made / printed” as illustrated is displayed. In addition to displaying the status, warnings such as prepress or discharge jam, paper feed or paper discharge jam, supply instructions for supplies such as paper, master, and ink are also displayed.

  When the paper type setting key 186 is pressed once, the paper types to be selected and set are as follows: thin paper: renewal paper, high quality 45 kg paper, etc., plain paper: copy paper, medium quality paper, high quality 55 kg paper, recycled paper, stencil High quality paper, thick paper: drawing paper, postcard (postcard), envelope, high quality 135 kg paper, high quality 180 kg paper, etc. are displayed on the display device 190. When the paper used with the four-way key 184 is selected / designated, the display device 190 Since the part of the selected / designated paper is displayed in black and white inversion above, it may be determined and set by finally pressing the enter key 180. Therefore, the paper type setting means for setting the paper type includes the paper type setting key 186, the enter key 180, and the four-direction key 184 in the above example.

  The paper type setting means is not limited to the combination of the above keys. For example, the number of keys corresponding to the paper type to be selected and set is provided, or the function is assigned to the selection setting keys 190a to 190d. It may be settable.

  Next, the main control configuration of the double-sided stencil printing apparatus 300 will be described with reference to FIG. In FIG. 14, the control device 100 has functions and configurations as means for controlling mainly a document reading operation, plate making / plate feeding operation, paper feeding operation and printing operation of the double-sided stencil printing apparatus 300. The control device 100 includes a CPU 101 (central processing unit), an I / O (input / output) port (not shown), a ROM 102 (read-only storage device), a RAM 103 (read / write storage device), a timer backed up by a battery (not shown), and the like. And a microcomputer having a configuration in which they are connected by a signal bus (not shown).

  As shown in FIG. 1, the control device 100 is provided in a control board arrangement section in the main body frame 130. The CPU 101 of the control device 100 (hereinafter simply referred to as “control device 100” for the sake of brevity) is provided with various signals from the operation panel 173 and detection signals from the various sensors provided on the main body frame 130. Based on the operation program and related data called from the ROM 102, the main motor 20 of the printing unit 16, the stepping motor 252 of the printing pressure range changing unit 28, the solenoid 62 of the locking unit 64, the plate making unit 15, the paper feeding unit 30, Each control target drive unit provided in the plate discharge unit 17, the paper discharge unit 19, the image reading unit 18, the press roller drive motor 55 provided in the refeed unit 45, the suction fan 109 of the refeed conveyance device 104, the belt The drive motor 105, the solenoid 70c, the solenoid 47 of the switching guide 46, and the drive mode provided in the moving means 87 are provided. It controls each operation or the like 94, and controls the duplex stencil printing device 300 overall operation.

  The control device 100 also determines the rotational position of the plate cylinder 1 and the printing speed based on various plate cylinder position signals from the plate cylinder position detection sensor 29 generally shown in FIG. .

  The ROM 102 stores in advance an operation program for the entire duplex stencil printing apparatus 300, necessary related data, and the like, and this operation program is appropriately called by the CPU 101. The relational data includes the printing speed including the paper type including the thickness of the paper 36 and the rotational speed of the belt driving motor 105 of the paper refeeding and conveying device 104 (in other words, the conveying speed that is also the linear speed of the conveying belt 108). And the relationship data set for each printing speed between the sheet type and the stop timing of the belt drive motor 105 after contacting the front end of the front surface printed sheet 36a with the stopper surface 53a.

  These relational data are, for example, a data table for changing the conveyance speed of the conveyance belt 108 determined in advance for each printing speed and set according to the paper type for each printing speed. The data is stored in advance in the ROM 102 as a data table for changing the stop timing of the belt drive motor 105 set according to the type.

  For example, in the case of a sheet 36 having a small thickness such as a refill paper, the sheet weight is lighter and the sliding with respect to the conveyor belt 108 is less than a thick sheet having a sheet weight. When the used paper 36a is released, the front end of the surface-printed paper 36a comes into contact with and stops at the stopper surface 53a of the stopper 70b by the conveyor belt 108, and then the stopper is released to be conveyed at a predetermined timing. The waiting time is set to a conveyance speed considering the conveyance stop timing of the conveyance belt 108 described later.

  When the front-side printed paper 36 is light and thin, the conveyance stop timing of the conveyance belt 108 is set to be advanced, and conversely, in the case of the heavy paper 36 such as heavy paper, in anticipation of slipping on the conveyance belt 108. The conveyance speed is increased and the conveyance stop timing is set to be delayed.

  In addition to the ROM 102, it is possible to write the related data as necessary so as to be able to cope with, for example, a design change by arranging a storage means such as a programmable PROM. is there.

  The RAM 103 has a function of temporarily storing calculation results of the CPU 101, a function of storing data signals and on / off signals set and input from various keys and various sensors on the operation panel 173 as needed.

  The control device 100 recognizes and grasps the rotational speed of the plate cylinder 1 as needed based on various plate cylinder position signals from the plate cylinder position detection sensor 29, and at the same time determines the rotational position (rotation phase position) of the plate cylinder 1 in real time. Recognize and grasp.

  The control device 100 changes the conveyance speed of the conveyance belt 108 of the refeed conveyance device 104 according to the type of the sheet, and also conveys the conveyance belt 108 after contacting the front end printed sheet 36a with the stopper 70b. It has a function as a control means which changes the conveyance stop timing. The transport operation of the transport belt 108 of the refeed transport device 104 includes transport until the paper 36a comes into contact with the stopper 53 and transport when the paper is removed from the stopper and refeeding is started. The speed may be set according to the paper type for the transport speed.

  In other words, the control device 100 changes the conveyance speed of the conveyance belt 108 of the refeed conveyance apparatus 104 according to the sheet type selected and set by the sheet type setting key 186, the enter key 180, and the four-direction key 184. And a function as a control means for controlling the belt drive motor 105 so that the conveyance stop timing of the conveyance belt 108 changes after the front end of the surface-printed paper 36a contacts the stopper surface 53a. Have

  More specifically, the control device 100 determines, based on the paper type data signal related to the paper type selected and set by the paper type setting key 186, the enter key 180, and the four-direction key 184, according to the paper type for each printing speed. A data table for changing the set conveying speed of the conveying belt 108, a data table for changing the stop timing of the belt driving motor 105, and data for changing the driving start timing of the conveying belt 108 when refeeding. The table is selected and set by calling the table from the ROM 102 and extracting the rotation speed of the belt drive motor 105 corresponding to the paper type data and the stop timing after the front end of the front surface printed paper 36a contacts the stopper surface 53a. The paper type and the conveyance speed of the conveyance belt 108 suitable for the present invention. As such, and functions as a control means for controlling the belt drive motor 105 so that the conveyance stop timing of the conveyance belt 108 corresponding to the paper type selected set.

  Based on the above-described configuration, the operation including the operation procedure of the double-sided stencil printing apparatus 300 in the present embodiment will be described with reference to FIGS. Since this operation is performed under the control of the control device 100, when explaining detailed operations such as activation, operation, and stop of actuators (control target drive means) such as various motors and various solenoids, the control device 100 The expression based on the command or the command signal is omitted as much as possible.

(Operation example 1)
First, an operation example 1 in which the simplex printing mode is set and the simplex printing is performed will be described. The operation example 1 is almost the same as the operation for performing single-sided printing by a conventional stencil printing apparatus, and is substantially the same as the operation for performing single-sided printing disclosed in JP-A-2003-200355, etc. explain. In the single-sided printing operation, the printing pressure range pattern III is used, and the cam plate 243A for normal printing is selected and used from among the components of the printing pressure range variable means 28. In the first operation example, in order to facilitate understanding of each operation, the A3 size is used as the master size, and the A3 size is used as the document size and the paper size.

  The user loads A3 size paper 36 as a paper size used for printing on the paper feed tray 35, opens the pressure plate 142, and places an A3 size document to be printed on the contact glass 135, and then again. The pressure plate 142 is closed. Thereafter, after setting the plate making conditions using various keys on the operation panel 173, the simplex printing key 188 is pressed to set the simplex printing mode.

  The user confirms the single-sided printing mode by turning on the LED 188a, and then presses the plate making start key 174. When the plate making start key 174 is pressed, a paper size detection signal is sent from the paper size detection sensor 117 and a document size detection signal is sent from the document size detection sensor 149 to the control device 100. Compare each signal. At this time, if the paper size and the document size are the same, the image reading operation is performed immediately. If the paper size and the document size are different, the control device 100 displays the fact on the display device 190 and pays attention to the user. Prompt.

  In the single-sided printing mode setting state, the switching guide 46 is stopped and held at the first displacement position (initial position) shown in FIG. When a plate making start key 174 is pressed to generate a start signal and is input to the control device 100, a series of operations from discharging to discharging are automatically performed.

  Prior to this, when the paper feed tray lifting / lowering motor is turned on, the paper feed tray 35 is raised, and the uppermost paper 36 comes into contact with the paper feed roller 33 to turn on a paper feed position detection sensor (not shown). When the control device 100 determines that the uppermost paper 36 is ready to be fed by detection, the paper feeding device 30 enters a paper feed standby state.

  First, in the plate removal unit 17, a plate removal operation for peeling the used master from the outer peripheral surface of the plate cylinder 1 is performed. When the start signal is input to the control device 100, the plate cylinder 1 starts to rotate. When the plate cylinder 1 reaches the home position where the clamper 7 is almost directly above, the operation of the main motor 20 is stopped and the plate cylinder 1 is stopped. 1 stops at the plate removal position.

  Next, the plate discharge driving means 126 is operated to rotate the drive rollers 164 and 167, and the lower plate discharge member 161 is moved to the plate cylinder 1 side, so that the endless belt 169 located on the outer peripheral surface of the driven roller 168 is moved. Abuts the used master.

  When the main motor 20 is started following the operation of the plate discharge driving means 126, the used master scooped up from the outer peripheral surface of the plate cylinder 1 by the rotation of the plate cylinder 1 and the movement of the endless belt 169 is the lower plate discharging member. 161 and the upper plate removal member 160 are nipped and conveyed and peeled from the outer peripheral surface of the plate cylinder 1. The peeled used master is discarded in the discharge box 162 and then compressed by the compression plate 163.

  Even after all the used masters are peeled off from the outer peripheral surface, the plate cylinder 1 continues to rotate, and stops until the clamper 7 rotates to the plate feed standby position located almost directly above. At the same time, an opening / closing device (not shown) is operated to open the clamper 7, and the double-sided stencil printing device 300 enters a plate feeding standby state.

  In parallel with the plate removal operation, the image reading unit 18 performs a document image reading operation. The original image is read by reflecting the reflected light illuminated by the fluorescent lamp 145 by the respective reflecting mirrors 143 and 144, and the reflected light related to the read original image is focused by the lens 146 and then image sensor 147. And is photoelectrically converted. The photoelectrically converted electrical signal is input to the A / D converter (not shown) in the main body frame 130, and then passes through a plate making control device (not shown) (which may be disposed in the control device 100). It is transmitted to a thermal head drive circuit (not shown).

  In parallel with the plate discharging operation and the image reading operation, the plate making unit 15 performs the plate making operation. That is, a digital image signal for controlling the heat generation of the heat generating elements of the thermal head 11 is transmitted to the thermal head 11 via the plate making control device and the thermal head driving circuit.

  As a result, a large number of heating elements of the thermal head 11 are energized in pulses in the main scanning direction to selectively generate heat, and the master transport motor 10 is driven to rotate, whereby the platen roller 9 and the transport roller pair 13 are driven. Starts rotating, and the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information while the master 8 is pulled out from the master roll 8a and is transported in the master transport direction X1.

  Then, the leading end of the master-made master 8Y is inserted between the clampers 7 that are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 reaches a certain set value, When it is determined that the leading end of the master-making master 8Y has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the leading-end of the master-making master 8Y is between the stage 6 and the clamper 7. Adsorbed and pinched by

  After clamping the front end of the master 8Y, the plate cylinder 1 resumes rotation at the same peripheral speed as the master transport speed by the rotation of the main motor 20, so that the master 8Y is ready for the platen roller 9 and the transport roller pair 13. Is fed to be wound around the outer peripheral surface of the plate cylinder 1.

  When it is determined that the plate making to the master 8 and the carrying of the set amount of the plate-making master 8Y have been completed by the rotation driving of the master carrying motor 10 by a predetermined number of steps, the cutter 12 is operated to cut the plate-making master 8Y. At the same time, the rotation of the platen roller 9 and the conveyance roller pair 13 is stopped by stopping the rotation of the master conveyance motor 10. When the rear end of the cut master 8Y is drawn out of the plate making unit 15 by the rotation of the plate cylinder 1 and completely wound around the outer peripheral surface of the plate cylinder 1, the master 8Y is transferred to the plate cylinder 1. When the winding of is finished, the plate feeding operation is finished.

  When winding of the plate-making master 8Y around the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate at a predetermined peripheral speed in the direction of the arrow shown in FIG. Be started.

  It should be noted that the solenoid 62 of the locking means 64 is turned off by the control device 100 until the leading edge of the paper 36 crosses / passes the paper detection sensor 32, that is, until the leading edge of the paper 36 is detected to be ON by the paper detection sensor 32. Therefore, the printing pressure range variable means 28 is in a non-operating state, so that the press roller 21 is held at a non-printing position, that is, an initial position separated from the outer peripheral surface of the plate cylinder 1.

  When the plate cylinder 1 rotates at a low speed in the direction of the arrow, first, the sheet feeding start light shielding plate 121 shown in FIG. 10 is engaged with the sheet feeding registration sensor 120, so that the sheet feeding registration sensor 120 is turned on. A paper start signal is generated, and this signal is used as a trigger to start the paper feed motor 37 (start rotation driving). When the paper feed motor 37 is driven to rotate clockwise in FIG. 11, the paper feed roller shaft 33a and the paper feed roller 33 are rotated clockwise through the operation of the mechanism shown in FIG. The uppermost sheet 36 on the sheet feed tray 35 in contact with the sheet 33 is separated into one sheet by the cooperative action with the separating member 34 while being conveyed, and the registration roller pair 31 on the downstream side in the sheet conveying direction X is separated. It is fed toward the nip part.

  Next, the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1, and the resist start light shielding plate 122 engages with the paper feed resist sensor 120, whereby the paper feed resist sensor 120 is turned on and a resist start signal is generated. Then, this signal is used as a trigger to activate the registration motor 41. The timing at which the registration motor 41 is activated, in other words, the timing at which the lower registration roller 31b is rotated is the image area of the single-side plate-making image 8YA in the plate-cylinder rotation direction of the plate-making master 8Y wound on the plate cylinder 1. It is set at a predetermined timing when the tip end reaches a position corresponding to the press roller 21.

  The registration motor 41 is driven to rotate counterclockwise in FIG. 11, and the registration lower shaft 32a and the registration roller lower 31b rotate counterclockwise through the operation of the mechanism shown in FIG. The leading edge of the paper 36 that is in contact with and waiting at the portion is fed while being pressed by the registration roller top 31 a and is sent out between the plate cylinder 1 and the press roller 21.

  Next, the leading edge of the sheet 36 fed by the registration roller pair 31 is normally entered, that is, the leading edge of the sheet 36 is within a predetermined time counted by the timer (or a predetermined amount supplied to the registration motor 41). This signal is input to the control device 100 when the paper detection sensor 32 detects the ON state within the number of pulses.

  Based on the detection signal of the leading edge of the sheet 36 from the sheet detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control device 100 instructs the solenoid 62 of the locking means 64 to energize. When the solenoid 62 is turned on, the cam plate 243A of the printing pressure range varying means 28 is operated.

  When the solenoid 62 is turned on, the plunger 62a is sucked, whereby the locking member 60 swings counterclockwise about the support shaft 61 against the urging force of the tension spring 63, and the locking claw 60a has a notch 22b. The other end portion side of the printing pressure arm 22 that is locked is released and rocked clockwise around the arm shaft 22a by the urging force of the printing pressure spring 242.

  By swinging the other end of the printing pressure arm 22, the outer peripheral surface of the cam follower 241 is opposed to the peripheral surface of the small-diameter portion of the cam plate 243A rotating in synchronization with the rotation of the plate cylinder 1. At the rotational position of the cam plate 243A (for example, the rotational position shown by borrowing FIG. 3), the pair of printing pressure arms 22 swings and rises clockwise around the arm shaft 22a by the urging force of the printing pressure spring 242. It becomes.

  As a result, as shown in FIG. 9, the press roller 21 has a single-side plate-making image 8YA of the plate-making master 8Y whose outer peripheral surface is wound on the surface region 1A or the back surface region 1B of the plate cylinder 1 shown in FIG. The nip portion 16a (see, for example, FIG. 3) is formed by displacing the paper 36 to a printing position where the printing pressure is applied by pressing the paper 36 slightly toward the left end of the margin.

  At the same time, the press roller drive motor 55 rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. By continuously pressing the sheet 36 against the plate-making master 8Y on the plate 1, the plate-making master 8Y is brought into close contact with the outer peripheral surface of the plate cylinder 1 and so-called printing is performed to fill the ink. In this printing, stencil printing is performed by the ink oozing from the opening portion of the opening portion 1a of the plate cylinder 1 to the punching portion of the master-making master 8Y and transferred to the surface of the paper 36.

  At this time, the ink roller 2 also rotates in the same direction as the rotation direction of the plate cylinder 1. The ink in the ink reservoir 4 is attached to the surface of the ink roller 2 by the rotation of the ink roller 2, and the amount of the ink is regulated when passing through the gap between the ink roller 2 and the doctor roller 3. To be supplied. On the other hand, in conjunction with the raising / lowering operation of the press roller 21, the refeed conveyance device 104 swings around the drive shaft 107 a via the refeed housing 110.

  In the single-sided printing mode, the belt driving motor 105 and the suction fan 109 of the refeed conveyance device 104 remain in an inoperative state, the driving motor 94 of the moving unit 87 also remains in an inoperative state, and the moving guide 81 is The initial position P2 is still occupied.

  In this way, plate printing corresponding to the single-side plate-making image 8YA in the plate-making master 8Y on the plate cylinder 1 is performed, and the plate cylinder 1 is further rotated in the rear end margin portion slightly to the right of the rear end of the single-side plate-making image 8YA. The peripheral surface of the large-diameter portion of the cam plate 243A rotating in synchronization with the plate cylinder 1 comes into contact with the outer peripheral surface of the cam follower 241.

  As a result, the printing pressure arm pair 22 swings and displaces counterclockwise against the urging force of the printing spring 242 around the arm shaft 22a, and the press roller 21 moves downward to occupy the non-printing position. Thus, the printing pressure application state by the press roller 21 is released.

  When the plate cylinder 1 rotates in the direction of the arrow in FIG. 1 and the clamper 7 reaches the vicinity of the press roller 21 in pressure contact with the plate cylinder 1, the plate cylinder 1 is driven to rotate in synchronization with the rotation of the plate cylinder 1. Since the cam plate 243A rotates the peripheral surface of the large diameter portion to a position where it abuts on the outer peripheral surface of the cam follower 241, the press roller 21 is separated from the clamper 7 protruding outward from the outer peripheral surface of the plate cylinder 1. That is, interference between the press roller 21 and the clamper 7 can be avoided.

  The single-sided printed paper 36 c that has been subjected to plate printing is further conveyed by the rotation of the plate cylinder 1 in the direction of the arrow in FIG. 1 while being pressed by the press roller 21, and the leading edge of the single-sided printed paper 36 c is located on the plate cylinder 1. The air blow from the peeling claw 170 and the peeling fan 171 approaching the outer peripheral surface is surely peeled off from the plate-making master 8Y on the plate cylinder 1, and the peeled single-sided printed paper 36c falls downward and is discharged. The sheet is conveyed to the sheet discharge belt 158 of 152 and is attracted to the upper surface of the sheet discharge belt 158 rotating in the direction of the arrow (counterclockwise) in FIG. The paper is conveyed to the downstream side and discharged to the paper discharge tray 172 with its both ends aligned by a pair of paper discharge side fences 172a and 172b.

  On the other hand, when the press roller 21 comes into contact with the outer peripheral surface of the plate cylinder 1, the plate cylinder 1 makes approximately three quarters of a turn, and when the large-diameter portion peripheral surface of the cam plate 243 </ b> A comes into contact with the cam follower 241, At the time when the pawl 60a and the notch 22b of the printing pressure arm 22 can be locked, the energization to the solenoid 62 is interrupted (turned off) by a command from the control device 100. Then, the locking member 60 is swung clockwise around the support shaft 61 by the urging force of the tension spring 63, and the notch 22b of the printing pressure arm 22 is locked to the locking claw 60a.

  As a result, the press roller 21 is returned to and held in the non-printing position away from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1 is rotated to the home position again and stopped. The stencil printing apparatus 300 enters a print standby state.

  Further, during paper feeding or plate-making, the platen roller 9 and the conveying roller pair 13 resume rotation, and the leading end of the cut master 8 is sent toward the nip portion of the conveying roller pair 13. If it is determined from the number of pulses of the master transport motor 10 that the tip of the cut master 8 has reached the nip portion of the transport roller pair 13 and has been sandwiched, the rotation of the platen roller 9 and the transport roller pair 13 stops, and the next It will be in the state of waiting for plate making in preparation for plate making.

  After the duplex stencil printing apparatus 300 enters a print standby state, when a printing condition is input using the printing speed setting key 183 and various keys on the operation panel 173 and the trial printing key 176 is pressed, the trial printing is performed. When the trial printing key 176 is pressed, the plate cylinder 1 is driven to rotate at the set printing speed, and one sheet of paper 36 is fed from the paper feeding unit 30. The fed paper 36 is temporarily stopped by the registration roller pair 31 and then fed at the same timing as that at the time of printing. The press roller 21 is pressed against the plate-making master 8Y on the outer peripheral surface of the plate cylinder 1.

  The single-sided printed paper 36c on which the printed image is formed is surely peeled off from the plate-making master 8Y on the plate cylinder 1 by the peeling claw 170 and the peeling fan 171, and the peeled single-sided printed paper 36c is discharged. The paper is transported by the paper transport device 152 in the same manner as described above and discharged onto the paper discharge tray 172.

  Along with the set printing speed, control target drive means such as various motors such as printing pressure range variable means 28, paper feed unit 30, paper discharge conveyance device 152, and various solenoids are driven at speeds and timings suitable for the print speed. Be controlled. When the position or density of the image is confirmed by trial printing, and the print start key 175 is pressed after the number of prints is input by the numeric keypad 179, the paper 36 is continuously fed from the paper supply unit 30, and the trial printing is performed. The printing operation is performed under the same conditions.

  When the set number of prints is exhausted, the plate cylinder 1 stops at the home position, and the double-sided stencil printing apparatus 300 enters the print standby state again. Compared with the printing operation at the time of printing, the normal printing operation does not count the number of sheets 36 used for printing as described above as a normal normal printing number, and the setting desired by the user The only difference is that the operations of paper feeding, printing, and paper discharge are performed at a speed corresponding to the printing speed.

  A sheet detection means corresponding to the sheet detection sensor 32 as described above is arranged on the conveyance path so as to detect the leading edge and the trailing edge of the surface printed sheet 36a that is held on the outer peripheral surface of the press roller 21 and conveyed to the nip portion 16a. You may arrange in.

  The reading operation in the image reading unit 18 may use ADF 148 in addition to the above. The difference from the operation example 1 in this case is as follows. That is, when an A3-size document 133 is set on the document tray 134 of the ADF 148 by the user, the ADF 148 of the image reading unit 18 is operated in parallel with the plate removal operation, so that one document 133 is read by the reading unit. The only difference is that it is delivered onto a certain contact glass 135. After that, as described above, the image of the original 133 is read as optical information by the operation of the scanner device 132.

(Operation example 2)
Next, an operation example 2 in which the duplex printing mode is set and duplex printing is performed will be described. In the operation example 2, all the printing pressure range patterns I, II, and III shown in FIG. 9 are used. For this reason, all of the three cam plates 243A, 243B, 243C of the multistage cam 243 constituting the constituent elements of the printing pressure range varying means 28 are used. In operation example 2, in order to facilitate understanding of each operation, a master size of A3 is used, and a document size and a paper size of A4 are used. Hereinafter, the points different from the operation example 1 will be mainly described.

  The user stacks A4 size paper 36 as a paper size used for printing on the paper feed tray 35, opens the pressure plate 142, and places the first A4 size original for surface printing on the contact glass 135. After placing, the pressure plate 142 is closed again. After that, the user presses the paper type setting key 186 on the operation panel 173 to display all the paper types used in the double-sided stencil printing apparatus 300 on the display device 190 and then use the four-way key 184 for double-sided printing. As the paper type, for example, “replacement” classified as thin paper is displayed in black and white reversed and finally determined by the enter key 180 to select and set.

  Furthermore, after setting the plate making / printing conditions with various keys on the operation panel 173, the duplex printing key 187 is pressed to set the duplex printing mode, and then it is confirmed by turning on the LED 187a that the duplex printing mode is set. Next, when the plate making start key 174 is pressed, a start signal is generated as in the single-sided printing mode, and this is input to the control device 100.

  Similarly to the first operation example, a paper size detection signal is sent from the paper size detection sensor 117 and a document size detection signal is sent from the document size detection sensor 149 to the control device 100. The control device 100 that receives these signals receives each signal. Compare signals. In the present embodiment, since the maximum paper size that can be printed by the plate cylinder 1 at the time of single-sided printing is A3 size horizontal placement, the paper size that can be used at the time of double-sided printing is up to A4 vertical placement.

  As a result of comparing the document size and the paper size, if the two sizes are the same, the image reading operation is immediately performed. If the two sizes are different, the control device 100 displays a warning on the display device 190 as a warning. Call attention to the user. When the paper size exceeds A4 portrait orientation, the control device 100 prohibits the double-sided printing operation and causes the display device 190 to display a message that prompts single-sided printing.

  When the plate making start key 174 is pressed, a series of operations from discharging to discharging are automatically performed as in the first operation example. Similarly to the first operation example, when the control device 100 determines that the uppermost sheet 36 in the sheet feeding tray 35 is ready to be fed, the sheet feeding unit 30 enters a sheet feeding standby state. After the plate removal operation similar to Operation Example 1 is performed, the plate cylinder 1 from which all used masters have been peeled off from the outer peripheral surface is stopped at the plate feed standby position as in Operation Example 1, and is opened and closed (not shown) The clamper 7 is opened by the device.

  In part in parallel with this plate removal operation, the image reading unit 18 performs the reading operation of the first original image for front surface printing in the same manner as in Operation Example 1, and the image data signal passes through the plate making control device and the like. Transmitted to the thermal head driving circuit. In part in parallel with the image reading operation, the plate making unit 15 performs plate making by the thermal head 11 as in the operation example 1, and the master 8 is pulled out from the master roll 8a by the rotation of the platen roller 9 and the conveying roller pair 13. While being transported in the master transport direction X1, the thermoplastic resin film portion of the master 8 is selectively heated and punched according to image information, and a surface plate-making image 8A for surface printing is formed in the first half of the master 8. (See the divided master-making master 8X shown in FIG. 9).

  Then, the leading end of the divided plate-making master 8X is inserted between the clampers 7 which are guided by the master guide plate 14 and expanded with respect to the stage 6, and the number of steps of the master transport motor 10 is set to a certain set value. When it is determined that the leading end of the divided prepress master 8X has reached between the stage 6 and the clamper 7, the clamper 7 is closed by the opening / closing device, and the leading end of the split prepress master 8X is moved to the stage 6 and the clamper. 7 and sucked and pinched between.

  After clamping the front end of the divided plate-making master 8X, the main cylinder 20 is activated to restart the rotation of the plate cylinder 1 at a substantially same peripheral speed as the master conveyance speed, so that the divided plate-making master 8X has the platen roller 9 and the conveyance roller pair. 13 is fed to be wound around the outer peripheral surface of the plate cylinder 1. When the controller 100 determines that the surface plate-making image 8A of the divided plate-making master 8X shown in FIG. 9 has been completed by the number of steps of the master conveyance motor 10, the platen roller 9, the conveyance roller pair 13, and the plate The rotation of the cylinder 1 is stopped, and the plate making standby state for making the back plate making image 8B for back printing in the next divided plate making master 8X is entered.

  Next, the user opens the pressure plate 142 again, places a second A4 size original for back side printing on the contact glass 135, and then closes the pressure plate 142 again. Thereafter, when the plate making start key 174 is pressed again, a start signal is generated and input to the control device 100. At this time, as in the case of the first document, the control device 100 compares the document size with the paper size and performs the same processing operation as described above.

  In the image reading section 18, the reading operation of the second original image for back side printing is performed in the same manner as the case of the first original, and the image data signal passes through the plate making control device (not shown) or the like. It is transmitted to the thermal head drive circuit. In the plate making unit 15, plate making is performed by the thermal head 11 as in the case of the first document, and the platen roller 9 and the carry roller pair 13 are rotated by the master carrying motor 10 being rotated again. The thermoplastic resin film portion of the master 8 is selectively heated and punched in accordance with image information while the master 8 is being pulled out from the master roll 8a and being transported in the master transport direction X1, and the back surface is formed on the back surface of the master 8 A back side plate-making image 8B for printing is formed (see FIG. 9).

  At this time, the plate cylinder 1 resumes rotating at the same peripheral speed as the master conveyance speed, so that the latter half of the divided plate-making master 8X is drawn out from the plate making unit 15 and wound around the outer peripheral surface of the plate cylinder 1. To go. Then, when the controller 100 determines that the last plate making image 8B of the divided plate making master 8X is completed by the number of steps of the master transport motor 10, the cutter 12 is operated and the divided plate making master is completed. The rear end portion of 8X is cut, the rotation of the platen roller 9 and the conveying roller pair 13 is stopped, and the rear end of the divided plate-making master 8X for one plate cut by the rotation of the plate cylinder 1 is the plate making section 15. The drawing and feeding operation of the divided plate-making master 8X to the plate cylinder 1 is completed.

  The document image reading operation and the image data inputting operation are not limited to the above-described examples. For example, the document 133 is automatically conveyed onto the contact glass 135 using the ADF 148, or an image is displayed from an external device (not shown). You may make it take in data.

  In this embodiment, when the plate making of the front plate making image 8A in the divided plate making master 8X is completed, the plate making standby state for making the back plate making image 8B for back printing in the next divided plate making master 8X is set. Accordingly, the rotation of the platen roller 9 and the conveying roller pair 13 and the plate cylinder 1 in the plate making unit 15 is temporarily stopped, but it is desirable to do as follows.

  That is, in addition to the automatic conveyance operation of the original 133 by the ADF 148, an image memory (not shown) including, for example, a bitmap memory or the like that stores a second original in advance and stores and stores image data related to the read original image. If the first and second image data are stored and stored in the image memory and the plate making is performed continuously while sequentially calling the image data, the plate making time can be shortened. And from the viewpoint of shortening the first print time (FPT).

  The printing operation is performed following the plate feeding operation. When the plate cylinder 1 stops at the home position, the control device 100 activates the printing pressure range variable means 28. In the following, when the printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 or the surface printing in the regular double-sided printing operation is first performed, the mark shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the pressure range pattern I is selected.

  That is, the stepping motor 252 shown only in FIG. 14 is rotationally driven, and through a known detailed operation through the rotation of the step cam (49), the cam plate 243B is selected, and the contour peripheral surface of the cam plate 243B becomes the cam follower 241. Abut.

  When the winding of the divided plate-making master 8X to the plate cylinder 1 is completed, the plate cylinder 1 starts to rotate in the direction of the arrow shown in FIG. 3 at a predetermined peripheral speed (usually a low speed for printing). Then, a paper feeding / printing process for printing is started. As in the first operation example, until the leading edge of the paper 36 is detected to be turned on by the paper detection sensor 32, the solenoid 62 of the locking means 64 is controlled to be turned off, so that the printing pressure range variable means 28 is not turned on. The press roller 21 is held in the non-printing position.

  As the plate cylinder 1 rotates in the direction of the arrow, as in the first operation example, first, the paper feeding start light shielding plate 121 shown in FIG. The uppermost first sheet 36 on the sheet feeding tray 35 that is in contact with the sheet feeding roller 33 is conveyed to be separated into one sheet by the cooperative action with the separation member 34 while being conveyed. It is sent out toward the nip part.

  After the leading edge of the sheet 36 thus fed comes into contact with the nip portion of the registration roller pair 31, the sheet 36 is held in a state where a predetermined curved deflection is formed at the leading end portion of the sheet 36. Next, when the plate cylinder 1 further rotates in the direction of the arrow in FIG. 1 and the registration start light shielding plate 122 engages with the paper feeding registration sensor 120, the registration motor 41 is started in the same manner as in the first operation example. The leading edge of the paper 36 that has been in contact with and waiting at the nip portion of the registration roller pair 31 is sent out between the plate cylinder 1 and the press roller 21 by the rotation of the registration roller pair 31 at a predetermined timing. It is. At this time, as in the operation example 1, the approach of the leading edge of the paper 36 fed by the registration roller pair 31 is normally detected by the paper detection sensor 32.

  Next, based on the detection signal of the leading edge of the paper 36 from the paper detection sensor 32 and the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the control device 100 turns on the solenoid 62 as in the first operation example. Thus, the cam plate 243B of the printing pressure range varying means 28 is operated. When the solenoid 62 is turned on, the detailed operation of the locking means 64 similar to that of the operation example 1 is performed, the contour peripheral surface of the cam plate 243B abuts the outer peripheral surface of the cam follower 241, and the outer peripheral surface of the cam follower 241 is the cam. At the rotational position of the cam plate 243B facing the small-diameter peripheral surface of the plate 243B and in a non-contact state, the printing pressure arm pair 22 swings clockwise around the arm shaft 22a by the biasing force of the printing pressure spring 242. Will rise.

  As a result, as shown in FIG. 9, the press roller 21 has a slightly smaller outer surface than the surface plate-making image 8A of the divided plate-making master 8X wound on the surface region 1A of the plate cylinder 1 shown in FIG. The paper 36 is pressed against the left end margin and is displaced to a printing position where printing pressure is applied to form a nip portion 16a (printing pressure by the press roller 21 in the printing pressure range pattern I shown in FIG. 9). See on-timing).

  At the same time, the press roller drive motor 55 rotates the press roller 21 at a substantially same peripheral speed as the peripheral speed of the plate cylinder 1, so that the press roller 21 rotates in the direction opposite to the rotation direction of the plate cylinder 1. By continuously pressing the sheet 36 against the surface plate-making image 8A portion of the divided plate-making master 8X, the surface plate-making image 8A of the divided plate-making master 8X is brought into close contact with the outer peripheral surface of the plate cylinder 1 and filled with ink. So-called printing is performed. In this plate printing, ink oozes out from the opening portion of the opening portion 1a of the plate cylinder 1 to the perforated portion of the surface plate-making image 8A in the divided plate-making master 8X and is transferred to the surface of the sheet 36, thereby making the stencil plate. Printing is performed.

  At this time, the ink roller 2 is also rotated in the same direction as the rotation direction of the plate cylinder 1 as in the first operation example, whereby the ink in the ink reservoir 4 is supplied to the inner peripheral surface of the plate cylinder 1. Thus, plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is performed, and the plate cylinder 1 further rotates, and the vicinity of the rear end of the surface plate-making image 8A corresponds to the nip portion 16a. When the rotation position is reached, the circumferential surface of the large diameter portion of the cam plate 243B and the cam follower 241 come into contact with each other, so that the printing pressure arm 22 rotates counterclockwise about the arm shaft 22a, and the press roller 21 does not print. Holds the position occupied. At this time, since the solenoid 62 of the locking means 64 has already been turned off by a command from the control device 100, the press roller 21 is returned to and held in the initial position state in which the non-printing position is occupied.

  In parallel with the printing operation, the solenoid 47 is turned on when the clamper 7 of the plate cylinder 1 passes over the press roller 21 occupying the non-printing position, whereby the switching guide 46 is shown in FIG. Thus, it is swung counterclockwise about the shaft 47a and occupies the second displacement position and stops. At the same time, when the drive motor 94 of the moving means 87 is activated (for example, forward rotation driving is started), the movement guide 81 is also printed by printing from the initial position (standby position) P2 as shown in FIG. In order to sandwich the leading end of the printed paper 36a, the four protrusions 81c are guided and moved along the guide groove 88 and move upward and diagonally to the right so as to occupy the movement position P1.

  When the movement guide 81 occupies the movement position P1 by the number of steps of the drive motor 94 reaching a certain set value, the lower release lever 83 is placed on the contour peripheral surface of the release cam 98 as shown by the solid line in FIG. By sliding on and sliding, the clamp claw 81b swings clockwise and stops in a state where it is released from the contact state with the upper surface of the clamping table 81f.

  When the movement guide 81 occupies the movement position P1 and stops, as shown in FIG. 3, the leading edge of the front surface printed paper 36a occupies the second displacement position and stops at the switching guide 46 and the peeling fan 171. By the operation of (see FIG. 1), it is reliably peeled off from the divided master-making master 8X (see FIG. 9) on the plate cylinder 1. The front end portion of the peeled surface-printed paper 36a is guided by the inclined surface of the clamp claw 81b provided on the movement guide 81, and the gap portion between the upper surface of the clamping table 81f and the free end of the clamp claw 81b that is opened. And then abuts against the sheet abutting surface 81e of the end fence 81d to abut and align the tip.

  When the front end of the front surface printed paper 36a is inserted into the gap between the upper surface of the clamping table 81f and the free end of the clamp claw 81b, the drive motor 94 moves the transport speed of the front surface printed paper 36a (the plate cylinder 1 and the press). The movement guide 81 is started to move diagonally downward to the left in the figure toward the initial position P2 by being activated (for example, reverse rotation driving is started) so as to be substantially the same speed as the circumferential speed by the rotation with the roller 21). To do.

  At this time, in FIG. 8, when the lower release lever 83 is disengaged from the contour peripheral surface of the release cam 98, the biasing force of the torsion coil spring causes the clamp claw 81b to swing counterclockwise and the free end of the clamp claw 81b. And the top end of the surface-printed paper 36a are clamped and clamped between the upper surface of the clamping table 81f.

  As described above, the moving guide 81 has the front surface printed paper 36a in a state where the front end of the front surface printed paper 36a is fixed and the front end of the front surface printed paper 36a abuts against the paper contact surface 81e. It moves to the left diagonally downward in the figure toward the initial position P2 at a moving speed that is substantially the same as the transport speed.

  As described above, after the plate printing corresponding to the surface plate-making image 8A in the divided plate-making master 8X on the plate cylinder 1 is completed, the press roller 21 is returned to and held in the initial position that occupied the non-printing position. In a paper feed standby state for the next paper feed.

  On the other hand, referring to FIG. 4, the surface-printed paper 36a is initially in a state of being clamped and fixed between the free end of the clamp claw 81b of the moving guide 81 and the upper surface of the clamping table 81f by the operation of the moving means 87. When the transfer guide 81 occupies the initial position P2 and is stopped toward the position P2, the release lever upper 82 comes into contact with the release pin 99 as shown by a two-dot chain line in FIG. As the clamp claw 81b is swung clockwise, the front end portion of the surface-printed paper 36a is released from the sandwiched / fixed state.

  At this time, after the rear portion of the surface-printed paper 36a is sucked and held by the operation of the paper refeeding / conveying device 104, the front-end portion of the surface-printed paper 36a is formed between the free end of the clamp claw 81b and the upper surface of the clamping table 81f. It is desirable that the position of the sheet 36a is opened in order to reduce the fluctuation of the sheet 36a and improve the positional accuracy of the sheet 36a.

  The solenoid 47 is turned off when the rear end of the front surface printed paper 36a passes the switching guide 46, so that the switching guide 46 is centered on the shaft 47a as shown by the solid line in FIG. 1 by the urging force of the tension spring. It is controlled so as to swing clockwise and return to the first displacement position (initial position) and stop.

  The front surface printed paper 36 a having its front end opened is first driven by the suction fan 109 of the refeed conveyance device 104 in response to a command from the control device 100, so that the non-printed image surface on the back surface is brought to the upper surface of the conveyance belt 108. As shown in FIG. 4, the sheet type immediately after the belt drive motor 105 is driven to rotate in the direction opposite to that at a specific rotation speed as shown in FIG. When the conveying belt 108 is temporarily stopped at a specific timing according to the sheet speed, that is, through the clockwise rotation of the sheet 107 after the conveying roller, the conveying belt 108 is moved at a conveying speed corresponding to the sheet type (for example, the sheet is changed in this operation example). Then, the front end of the front surface printed paper 36a is conveyed so that the front end of the new traveling direction comes into contact with the stopper surface 53a, and the front end of the paper 36a comes into contact with the stopper surface 53a. Immediately after that, the conveyance is stopped at a timing according to the type of the sheet, so that the leading edge of the surface printed sheet 36a is minimized by the energy when the surface printed sheet 36a contacts the stopper surface 53a. Thus, the belt drive motor 105 is controlled.

  Next, based on the rotational position information of the plate cylinder 1 from the plate cylinder position detection sensor 29, the surface of the plate cylinder 1 corresponds to a predetermined position, that is, the reverse side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1. When the control device 100 determines that the rotational position of the plate cylinder 1 that enables printing on the back surface of the finished paper 36a has been reached, the solenoid 70c is turned on, whereby the stopper 70b is lowered to complete the front surface printing. The conveyance belt is driven after the leading end of the sheet 36a is released from the contact state with the stopper surface 53a.

  At the same time, the press roller drive motor 55 shown in FIG. 2 is driven to rotate, and the surface-printed paper 36a is attracted to the transport belt 108 by the action of the suction fan 109 and is on standby, and the solenoid 70c is turned on to stop the stopper. After the stopper is released by lowering 70b, the sheet 36a starts to move by driving the belt drive motor 105, and is guided along the outer peripheral surface of the press roller 21 by the roller guide plate 50. The press roller 21 is conveyed while being turned upside down toward the nip portion 16a formed by pressure contact.

  Although the driving speed of the conveyor belt 108 will be described later, it is set to be higher than the peripheral speed of the plate cylinder until at least the leading edge of the sheet is detected by the leading edge detection sensor. When performing printing corresponding to the back side plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 or back side printing in a regular double-sided printing operation described later, the printing pressure range shown in FIG. The printing pressure range variable means 28 is controlled so that the printing pressure ON timing by the press roller 21 in the pattern II is selected.

  That is, the stepping motor 252 shown in FIG. 14 is driven to rotate and a known detailed operation is performed through the rotation of the step cam (49), so that the cam plate 243C is selected and the contour peripheral surface of the cam plate 243C becomes the cam follower 241. Abut.

  In parallel with this conveyance, when the predetermined rotation position of the plate cylinder 1, that is, the vicinity of the front end of the back plate-making image 8B on the divided plate-making master 8X on the plate cylinder 1 reaches the rotation position corresponding to the nip portion 16a. When the small diameter portion of the cam plate 243C rotating in synchronism with the rotation of the plate cylinder 1 is in a non-contact state facing the cam follower 241, the press roller 21 has an outer peripheral surface as shown in FIG. 4, the back surface of the surface-printed paper 36a (upper surface in FIG. 4) is provided at the front end portion slightly left of the rear surface plate-making image 8B of the divided plate-making master 8X wound on the back surface region 1B of the plate cylinder 1 shown in FIG. Is pressed and displaced to a printing position where printing pressure is applied, and the nip portion 16a is formed by the urging force of the printing pressure spring 242 to perform double-sided printing for printing (see the mark shown in FIG. 9). Pressure range Referring printing pressure ON timing by the press roller 21 in over emissions II).

  In this way, a plate on which double-sided printing has been performed in which ink is filled corresponding to the backside plate-making image 8B in the divided plate-making master 8X on the plate cylinder 1 and a backside printed image is formed on the backside of the front surface printed paper 36a. The double-sided printed paper 36b for attachment is similar to the paper discharge operation of the single-sided printed paper 36c, and the plate cylinder 1 is blown by the air from the peeling claw 170 and the peeling fan 171 whose leading end approaches the outer peripheral surface of the plate cylinder 1. The double-side printed paper 36b that has been reliably peeled off from the upper divided master 8X is dropped downward and sent to the paper discharge conveying device 152, and rotated counterclockwise as shown in FIG. The sheet is discharged to the sheet discharge tray 172 while being attracted to the upper surface of the sheet discharge belt 158 by the suction force of the suction fan 159 and conveyed to the downstream side in the sheet conveyance direction X while being sucked and held. .

  On the other hand, when the press cylinder 21 makes approximately three-quarters of a turn from the time when the press roller 21 contacts the outer peripheral surface of the plate cylinder 1 and the cam follower 241 contacts the large diameter peripheral surface of the cam plate 243C, an example of operation is performed. 1, the press roller 21 is returned to and held in the non-printing position away from the outer peripheral surface of the plate cylinder 1, and the plate cylinder 1 rotates to the home position again and stops. After the attaching operation, the double-sided stencil printing apparatus 300 enters a print standby state for the next regular double-sided printing.

  After the double-sided stencil printing apparatus 300 is in a print standby state, the printing conditions are input using the printing speed setting key 183 and various keys on the operation panel 173, and the position or density of the image is confirmed by trial printing as appropriate. When the print start key 175 is pressed after the number of prints is input through 179, the paper 36 is continuously fed from the paper supply unit 30, and the duplex printing operation for the set number of sheets set by the ten key 179 is performed.

[2] Each example of aligning the front end of the paper after surface printing with the printing surface start position of the master FIG. 15 is a plate-making means for making a master as a master divided into two front and rear surfaces in the feed direction of the stencil paper described in FIGS. In the double-sided stencil printing apparatus having the above, the configuration necessary for the explanation of the present invention is extracted and schematically shown.

  The main configuration of the double-sided stencil printing apparatus shown in FIG. 15 is as follows. The plate cylinder 1 is rotated at a predetermined peripheral speed by the main motor 20 during printing. The press roller 21 can be brought into contact with and separated from the plate cylinder 1 and is rotatably installed by being pressed against the outer surface of the plate cylinder 1 by a nip portion 16a. The plate cylinder position detection sensor 29 is drum rotation angle information detection means for detecting drum rotation angle information of the plate cylinder 1. The stopper 70b accepts the front-side printed paper 36a (hereinafter also referred to as the paper 36a) printed on the first side of the two sides when the front and back sides of the paper to be printed are switched and printed on the two sides. And hold.

  The stopper 70b is driven by a solenoid 70c connected thereto. The solenoid 70c constitutes a main part of the stopper release mechanism. This stopper release mechanism has a function of releasing the contact between the paper and the stopper when the second surface of the two surfaces is printed. A conveyance belt 108 stretched between the front conveyance roller 106 and the rear conveyance roller 107 constitutes conveyance belt means for conveying paper. The conveying belt means is driven by a belt drive motor 105 that is a stepping motor, and the sheet feed amount and speed are controlled according to the control information of the control device 100.

  In the middle of the paper conveyance path from the stopper 70b through the press roller 21 to the nip portion 16a, in this example, at the upstream side of the roller guide plate 50 on the paper conveyance path, the outer peripheral surface of the press roller 21 and the roller guide plate The roller guide plate 50 is provided with a leading edge detection sensor 400 as a leading edge detecting means for detecting the leading edge of the surface-printed paper 36 a that moves in the space between the inner peripheral surface 50. The tip detection sensor 400 may be a reflection type or a transmission type. Information detected by the tip detection sensor 400 is output to the control device 100.

  The control device 100 drives and controls the belt drive motor 105 based on the paper leading edge detection information detected by the leading edge detection sensor 400 and the drum rotation angle information detected by the plate cylinder position detection sensor 29 serving as drum rotation angle information detection means. .

  Based on the drum rotation angle information from the paper feed registration sensor 120 that detects the drum rotation angle information of the plate cylinder 1, the solenoid 70c is operated and the stopper 70b is lowered from the protruding position at a certain timing suitable for the back side printing. The retracted position is entered, and the conveyance stop state of the paper 36a is released.

  In response to the rotation of the belt drive motor 105, the conveyance belt 108 also starts to rotate, and conveys the paper 36a in the standby state toward the nip portion 16a that is the contact point between the plate cylinder 1 and the press roller 21 in the direction of the broken line arrow in FIG. To do. The distance L1 from the stopper surface 53a to the nip portion 16a is fixed in terms of layout. L1: Set to 125.66 mm. Further, as described above, the belt drive motor 105 is a stepping motor, and as will be described later, one step (pulse) is set to 0.31459 mm as the belt feed amount (0.314159 mm / step).

  As described above, in order to feed the paper 36a from the stopper surface 53a to the nip portion 16a, the belt drive motor 105 requires L1: 125.66 mm / 0.314159 (mm / step) = 400 steps (paper feed amount theoretical value). It becomes.

  Although a paper feed start light shielding plate 121 is provided at a specific position on the outer peripheral surface of the plate cylinder 1, for ease of explanation, the end position of the paper feed start light shielding plate 121 is the front end position of the sheet to be conveyed. Set the stamp face start position of the stencil sheet to be matched. The normal sheet feeding start light-shielding plate 121 is set at a stop position of the plate cylinder 1, and the front end position of the sheet is set at a certain angle from the stop position.

The distance from the paper feed registration sensor 120 to the nip portion 16 a on the outer periphery of the plate cylinder 1 depends on the outer diameter of the plate cylinder 1 and the installation position of the paper feed registration sensor 120. If the plate cylinder 1 has an outer diameter of 180 mm and the paper feed registration sensor 120 is installed at a position 180 degrees opposite to the nip portion 16a, the paper feed start shading plate 121 passes through the paper feed registration sensor 120. And the distance from the nip portion 16a to
Outer diameter 180 × circumferential ratio π × (180 degrees / 360 degrees) = 282.74 mm.

  The unit of drum angle detection of the rotary encoder 351 that rotates coaxially with the main motor 20 is 0.2 degrees. When the plate cylinder 1 is rotated 0.2 degrees, the distance is 0.314159 mm. As described above, the distance traveled by 0.2 degrees and the feed amount of one step of the belt drive motor 105 are set to be equal.

  Thus, the distance between the outer periphery of the plate cylinder 1 (0.314159 mm) at the minimum step angle (0.2 degrees) of the rotary encoder 351 and the minimum belt feed amount (0.31459 mm) by the belt drive motor 105 are equivalently related. I have to. Alternatively, there is no particular problem even if the relationship of multiples is set, for example, the detection unit of the rotary encoder 351 is set to a multiple of 0.2 degrees (0.4 degrees, 0.8 degrees). It may be. By having such a relationship, it is easy to control the printing start position of the paper and the printing face start position of the pre-made stencil sheet.

  From the paper feed registration sensor 120 to the nip portion 16a, the slit (pulse) of the rotary encoder 351 is 180 degrees / 0.2 degrees = 900 pulses. That is, the nip portion 16a is reached when 900 pulses from the paper feed registration sensor 120 are reached.

Control for aligning the leading edge of the paper 36a sent by the conveyor belt 108 with the position of the paper feeding start light shielding plate 121 will be described below.
The number of slits is measured by the rotary encoder 351 after the paper feed start light-shielding plate 121 passes through the paper feed registration sensor 120, and several pulses are required until the paper feed start light-shielding plate 121 reaches the nip portion 16a. Will be subtracted. For example, when the paper feed registration sensor 120 is ON, 900 pulses to the nip portion 16a, and after 1 pulse from the paper feed registration sensor 120, 899 pulses to the nip portion 16a, 2 pulses → 898 pulses, and finally 900 pulses. → With the remaining 0 pulses, the sheet feeding start light-shielding plate 121 reaches the nip portion 16a.

  Similarly, in the belt drive motor 105, since the belt feed amount from the start of driving of the belt drive motor 105 (stopper surface 53a) to the nip portion 16a is 400 pulses, the number of steps of the belt drive motor 105 is counted, and the nip Some more are subtracted to the part 16a. When one pulse is sent, 399 pulses, 2 pulses → 398, and finally 400 pulses → the remaining 0 pulses, the leading edge of the paper 36a conveyed by the belt reaches the nip portion 16a.

  The leading edge detection sensor 400 is installed so as to detect the leading edge of the sheet 36a at a position 22 mm from the stopper surface 53a. Therefore, in theory, the sensor detection is turned on at 22 pulses / mm from the stopper surface 53a at a pulse of 22 mm / 0.314159 (mm / step) = 70. However, if the sensor detection is turned ON with 80 pulses from the stopper surface 53a due to slippage or the like during conveyance, the value actually detected after conveyance is delayed by 10 pulses from the theoretical value of the feed amount.

  Therefore, when the conveyance motor 105 is subtracted, the difference in feed amount is corrected by adding 10 pulses. That is, 400 pulses−80 pulses = 320 pulses at the position of the tip detection sensor 400, so 10 pulses are added and set to 330 at this time. Then, one pulse (feed pulse) is subtracted from 330 pulses again. Since there are 330 pulses from the position of the tip detection sensor 400 to the nip portion 16a, there is no problem even if the position is subtracted from the position of the tip detection sensor 400.

  Alternatively, as shown in FIG. 16A, the leading end of the sheet 36a is bent and abutted against the stopper surface 53a, so that the leading end of the sheet 36a is moved from its original position as shown in FIG. In some cases, the value actually transported and detected is advanced by 10 pulses from the theoretical value of the feed amount. If the sensor detection is turned ON with 60 pulses from the stopper surface 53a, the value actually transported and detected is 10 pulses ahead of the theoretical value of the feed amount.

Therefore, when the transport motor 105 is subtracted, the difference in feed amount is corrected by subtracting 10 pulses. That is, since 400 pulses-60 pulses = 340 pulses at the position of the tip detection sensor 400, 10 pulses are subtracted, and 3 30 is obtained at this time. Then, one pulse (feed pulse) is subtracted from 330 pulses again.

  In FIG. 17 shown as a comparative example, the re-feeding registration roller 510 can be brought into contact with and separated from the press roller 21, and the leading end of the sheet 36a is retracted from the stopper 530 as shown in FIG. Stopped by a stopper 530. As shown in FIG. 17B, in a state where the re-feeding registration roller 510 is moved upward with respect to the stopper 530, the paper 36a is pushed up, the stopper is released, and the paper 36a comes into contact with the press roller 21. Is conveyed together with the press roller 21.

  In such a configuration, since the conveyance speed of the sheet 36a is restricted by the press roller 21 immediately after the stopper is released, the feeding speed of the sheet 36 cannot be controlled in order to correct the error Δ associated with the deflection of the leading end of the sheet 36a. On the other hand, in this embodiment, the refeeding registration roller is not provided, and the stopper means (solenoid 70c) is provided as a separate and independent structure. Therefore, after the stopper is released, the leading edge detection sensor 400 causes the speed of the paper 36a. It is possible to match the leading edge position of the sheet and the start of the printing surface.

  The control when the sheet conveying speed of the belt driving motor 105 is the same as the peripheral speed of the plate cylinder 1 will be described. Since the feed amount of one pulse of the rotary encoder 351 is equal to the feed amount of one pulse of the belt drive motor 105, the relationship of the feed amount per unit time is also the same. That is, when subtracting one pulse at a time for the rotary encoder 351 per unit time (1 ms), the belt drive motor 105 is also subtracted one pulse at a time.

  The rotary encoder 351 takes 1 pulse / ms subtraction from 900 pulses = 900 ms. The transport motor 105 takes 1 pulse / ms subtraction from 400 pulses = 400 ms. If the belt drive motor 105 is started when the rotary encoder 351 is 900-500 = 400 after 500 pulses, both of the remaining pulses become 400 pulses, so that the front end position of the paper at the nip portion 16a is the start position of the preprinted stencil sheet. Will fit.

  A description will be given of how the sheet feeding start light-shielding plate 121 (printing surface start position) and the leading end of the sheet are determined. As described above, the rotary encoder 351 and the conveyor belt 108 calculate (subtract) the remaining pulses (distance) to the nip portion 16a. When the relationship between the remaining pulses of the rotary encoder 351 and the remaining pulses of the belt drive motor 105 is always the same value, it is determined that the sheet feeding start light-shielding plate 121 (printing surface start position) is aligned with the sheet leading edge position. Yes.

  Therefore, if the belt drive motor 105 starts 500 pulses after the rotary encoder 351, the remaining pulses at the same point have the same value, and the paper feed start light shielding plate 121 (printing surface start position) and the paper leading edge position ideally match. However, since the sheet is also transported, the leading edge of the sheet is delayed due to sliding, or as described above with reference to FIG. The paper may jump forward and the leading edge of the paper may be advanced.

  In these cases, the leading edge detection sensor 400 detects the leading edge of the sheet, and when the belt drive motor 105 starts and is delayed until the leading edge detection sensor 400, the conveyance speed of the conveyance belt 108 is faster than the peripheral speed of the plate cylinder 1. For example, the operation is performed at 1.2 times speed so that “the remaining pulse of the rotary encoder 351 = the remaining pulse of the belt drive motor 105”. If you are moving in the opposite direction, decelerate to about 0.8 times speed.

  When the leading edge detection sensor 400 detects the leading edge of the sheet due to uneven rotation of the plate cylinder 1 or the like, and the position where the leading edge position of the sheet and the printing surface start position of the stencil sheet is made is the nip portion 16a or later, the conveyor belt The speed of 108 is set higher than the set value, and the position where the leading edge position of the sheet and the stamping surface start position of the stencil sheet after the plate making match is set immediately before the nip portion 16a.

  In this example, since it is 1 pulse / ms, “the remaining pulse of the rotary encoder 351 = the remaining pulse of the belt drive motor 105” means that the peripheral speeds of both are equal. After determining that the remaining pulses are equal, the plate cylinder position detection sensor 29 (rotation angle information detecting means) calculates the rotation speed fluctuation, feeds back the fluctuation to the belt drive motor 105, and removes the paper 36a. Transport.

After the peripheral speed of the plate cylinder 1 and the peripheral speed of the conveying belt 108 by the belt drive motor 105 become equal, the belt drive motor 105 is based on the output signal of the drum rotation angle information detection means by the plate cylinder position detection sensor 29. By performing feedback control to change the feed amount per hour of the belt drive motor 105, the rotation unevenness of the plate cylinder 1 is dealt with.

Alternatively, after the peripheral speed of the plate cylinder 1 and the peripheral speed of the conveying belt 108 by the belt drive motor 105 become equal, the belt drive motor 105 detects from the output signal of the drum rotation angle information detection means by the plate cylinder position detection sensor 29. The plate cylinder is subjected to feedback control so that the obtained remaining distance to the nip portion 16a and the remaining distance from the leading edge of the paper 36a sent by the belt driving motor 105 to the nip portion 16a are equal. Deal with the rotation unevenness of 1.

  In the above description, the case where the conveying speed of the conveying belt 108 by the belt driving motor 105 and the peripheral speed of the plate cylinder 1 are equal at the start of the belt driving motor 105 has been described. Hereinafter, a case where the speed of the conveyor belt 108 by the belt driving motor 105 is higher than the peripheral speed of the plate cylinder 1 will be described.

  The reason why it is necessary to increase the speed is that if the printing speed is increased at the same speed, the start time of the belt drive motor 105 is also relatively faster (for example, the rotary encoder 351 starts after 500 pulses have elapsed). . Then, if the printing speed is increased, the belt driving motor 105 is started before the sheet 36a comes into contact with the stopper 70b, and the operation of the stopper 70b is not in time. Therefore, it is necessary to delay the start timing as much as possible, and the conveyance speed of the conveyance belt 108 is increased by the amount corresponding to this delay so that the remaining pulses of both coincide.

  The case where the peripheral speed of the conveyor belt 108 by the belt drive motor 105 is 1.2 times the peripheral speed of the plate cylinder will be described. Since the feed amount of one pulse of the rotary encoder 351 is equal to the feed amount of one pulse of the belt drive motor 105, when the speed of the belt drive motor 105 is 1.2 times, the relationship of the feed amount per unit time is as follows. Pulse: Belt drive motor becomes 1.2 pulses. That is, when subtracting one pulse for the rotary encoder 351 in unit time (1 ms), subtracting 1.2 pulses for the belt drive motor 105.

  While the rotary encoder 351 takes 1 pulse / ms subtraction = 900 ms from 900 pulses to the remaining pulse 0, the belt drive motor requires 1.2 pulses / ms subtraction = 333.3 ms (from 400 pulses to the remaining pulse 0). 400 / 1.2).

  Therefore, if the belt drive motor 105 is started when the rotary encoder 351 has 567 pulses and 900−567 = 333 pulses, the leading edge position of the sheet will theoretically match the printing surface start position of the stencil sheet after stencil printing at the nip portion 16a. Become. Even if it starts 67 pulses later than the case of the same speed, it will be in time. The actual error is corrected by the tip detection sensor 400 and corrected according to the above-described example. That is, the theoretical value of the amount of paper fed by the belt drive motor 105 is compared with the amount actually detected by conveyance, and the difference in the amount of feeding is corrected so that the leading edge position of the paper matches the printing surface start position of the stencil sheet. Feedback control.

  If the leading edge detection sensor 400 detects the leading edge of the sheet and the position where the leading edge position of the sheet and the printing surface start position of the stencil stencil sheet meet is after the nip portion 16a, the speed of the conveyor belt 108 is higher than the set value. The position where the leading edge position of the sheet coincides with the printing face start position of the stencil sheet after making the plate is set immediately before the nip portion 16a.

When the front end position of the sheet is coincident with the printing face start position of the stencil sheet after the plate making at the nip portion 16a, the conveying speed of the conveying belt 108 is made equal to the peripheral speed of the plate cylinder 1.
Further, after the peripheral speed of the plate cylinder 1 and the peripheral speed of the conveying belt 108 by the belt drive motor 105 become equal, the belt drive motor 105 outputs the output signal of the drum rotation angle information detection means by the plate cylinder position detection sensor 29. Based on this, feedback control for changing the feed amount per hour of the belt drive motor 105 is performed to cope with uneven rotation of the plate cylinder 1.

Alternatively, after the peripheral speed of the plate cylinder 1 and the peripheral speed of the conveying belt 108 by the belt drive motor 105 become equal, the belt drive motor 105 detects from the output signal of the drum rotation angle information detection means by the plate cylinder position detection sensor 29. The plate cylinder is subjected to feedback control so that the obtained remaining distance to the nip portion 16a and the remaining distance from the leading edge of the paper 36a sent by the belt driving motor 105 to the nip portion 16a are equal. Deal with the rotation unevenness of 1.

  Of the control methods described so far, in the example in which “the remaining pulse of the rotary encoder 351 = the remaining pulse of the belt drive motor 105”, the remaining pulse of the rotary encoder 351 and the remaining pulse of the belt drive motor 105 are equivalent. After that, the belt drive motor 105 is controlled in accordance with the rotation unevenness of the plate cylinder 1 by feedback control. Therefore, when the rotation unevenness of the plate cylinder 1 is large, it is difficult to follow the belt drive motor 105, or because this control method always calculates (controls), the calculation processing of the CPU becomes enormous. It is possible.

  Therefore, as shown in FIG. 18, a registration auxiliary roller 51 that can contact and separate from the press roller 21 is provided. The registration auxiliary roller 51 is located at the boundary between the guide plate 70a and the roller guide plate 50 as shown in FIG. The resist auxiliary roller 51 has a roller shape, is a high friction material, and is an elastic body having oil resistance (ink corrosion resistance), for example, nitrile rubber (NBR). The resist auxiliary roller 51 is divided into skewers and supported on a shaft 51a. Has been. The registration auxiliary roller 51 is normally held in a state where it occupies a non-contact position on the lower side of the press roller 21, and can freely rotate at one end of each swing arm 71 in which both ends of the shaft 51 a have a substantially square shape. Is attached. Each swing arm 71 has a bent portion fixed to a support shaft 72 that is rotatably supported between the printing pressure arms 22.

  As a result, when the registration auxiliary roller 51 occupies the contact position, it receives the rotational force of the press roller 21 and rotates in the direction opposite to the rotation direction (counterclockwise) of the press roller 21 (counterclockwise). 21, the paper 36 a can be sandwiched and conveyed.

  In FIG. 18, a plunger 74 of a solenoid 73 is attached to the other end of the swing arm 71 on the back side of the drawing sheet via a pin. The solenoid 73 is a pull type, and is attached and fixed to one printing pressure arm 22 via a bracket which is a non-moving member (not shown).

  Further, at the other end of the swing arm 71, one end thereof is fixed to one printing pressure arm 22, and a tension spring 75 that biases the registration auxiliary roller 51 around the support shaft 72 in a direction that always occupies the non-contact position. The other end is attached. The solenoid 73 has a function of displacing the registration auxiliary roller 51 so as to occupy the contact position at a predetermined timing.

  When the solenoid 73 is actuated against the urging force of the tension spring 75 (ON operation), the registration auxiliary roller 51 abuts the outer peripheral surface thereof against the outer peripheral surface of the press roller 21 with a predetermined pressure contact force. , The paper 36a is brought into contact with the outer peripheral surface of the press roller 21 for a predetermined time, and receives the rotational force of the press roller 21 to assist the conveyance of the paper 36a while being rotated in the clockwise direction opposite to the press roller 21. When the operation of the solenoid 73 is released (off operation), the urging force of the tension spring 75 causes the outer peripheral surface to be separated from the outer peripheral surface of the press roller 21 and occupy the non-contact position.

  In the above example, when the control device 100 determines that the remaining pulse of the rotary encoder 351 and the remaining pulse of the belt drive motor 105 become equal after the sheet 36a is driven by driving the solenoid 70c, the registration auxiliary roller 51 is moved by the solenoid 73. Operate and abut against the press roller 21. After the contact, the feedback control of the belt drive motor 105 is stopped, and the belt drive motor 105 is operated at an ideal plate cylinder peripheral speed, or the operation of the belt drive motor 105 is stopped.

  In this example, since the press loaf 21 is in contact with the plate cylinder 1, it rotates at the same speed as the peripheral speed of the plate cylinder 1. Therefore, even if there is rotation irregularity in the plate cylinder 1, it rotates equally with rotation irregularity. Further, by pressing the registration auxiliary roller 51, the influence of the rotation unevenness is eliminated, the load on the CPU 101 in the control device 100 can be reduced, and the registration can be improved.

  It can be said that the present invention as a whole can be said that as the peripheral speed of the conveyor belt 105 is faster than the peripheral speed of the plate cylinder, it is possible to match the printing surface start position and the leading edge position of the paper 36a in a shorter time from the start of conveyance. . With respect to the plate cylinder 1, the leading edge position of the sheet matches the printing surface start position with a smaller amount of rotation from the start of control.

  That is, the conveyance start timing of the sheet 36a by the conveyance belt 105 can be delayed as compared with the conventional case, and the printing surface start position matches the printing sheet leading edge position by the amount of rotation of the plate cylinder 1 corresponding to the short time deducted by the delayed time. For this reason, the influence of unevenness in the rotational speed of the plate cylinder 1 is reduced.

  For example, starting the conveyance of the paper 36a at the position where the printing surface start position is 50 mm away from the conveyance belt 108 to the nip portion 16a and starting the conveyance of the paper 36a from the conveyance belt 108 to the nip portion 16a. However, the effect of uneven rotation speed is small for 33 mm.

  From the above, the peripheral speed of the conveyor belt 108 only needs to be higher than the peripheral speed of the plate cylinder 1. However, when trying to increase the peripheral speed of the conveyor belt 108, the belt drive motor 105 that is the drive source becomes a problem.

  The plate cylinder 1 can be printed at each of six rotation speeds of 30, 60, 75, 90, 120, and 135 rpm, and is rotated at a peripheral speed corresponding to these rotation speeds. For example, if the rotation speed of the belt drive motor 105 is changed from the 1st speed of 30 rpm, which is the minimum rotation speed of the plate cylinder 1, to the rotational speed corresponding to 135 rpm = 270 rpm, which is 2 times the speed, it is 9 times the current speed. A stepping motor that can change the speed is required, which results in a very expensive part.

  In the belt drive motor 105, since the rotational speed corresponding to the lowest speed of 30 rpm, which is a single speed, is necessary for control, the rotational speed corresponding to 135 rpm is lowered. In reality, the lowest speed of 1.4 times is the limit.

Accordingly, the high speed region of the belt drive motor 105 is 1.4 times the lowest speed and the low speed region is doubled or tripled so that the peripheral speed ratio increases as the speed decreases.
That is, before the front end position of the sheet matches the printing surface start position of the stencil sheet, the ratio of the peripheral speed of the conveyor belt 108 and the peripheral speed of the plate cylinder 1 by the belt drive motor 105 is reduced. It is better to control according to the peripheral speed ratio characteristic in which the peripheral speed (acceleration ratio) of the conveyor belt 108 increases.

  Thereby, even when the upper limit of the rotational speed of the belt drive motor 105 is limited, the rotational speed of the plate cylinder 1 becomes uneven due to the rotation of the belt drive motor 105 that becomes relatively higher as the peripheral speed of the plate cylinder 1 becomes lower. It is possible to match the position of the leading edge of the sheet with the start position of the stamped stencil sheet in a short operation time that is less affected by the above. The belt drive motor 105 can have a realistically possible speed of about 1.4 times the lowest speed.

It is a partial cross section front view of the principal part of the double-sided stencil printing apparatus which shows embodiment of this invention. FIG. 2 is a partial cross-sectional front view showing an enlarged configuration and operation around a printing unit, a refeed unit, and a printing pressure range variable unit of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a partial cross-sectional front view showing an enlarged configuration and a surface printing operation around a printing unit, a refeed unit, and a printing pressure range variable unit of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a partial cross-sectional front view showing an enlarged view of a configuration around a printing unit and a refeed unit of the double-sided stencil printing apparatus in FIG. 1 and an operation state in which a front end of a surface printed paper is in contact with a stopper. FIG. 2 is a partial cross-sectional front view illustrating an enlarged double-sided printing operation in parallel with the configuration of the printing unit and the refeeding unit of the double-sided stencil printing apparatus in FIG. FIG. 5 is a top view of the re-feeding means (re-feeding conveyance device, stopper, re-feeding registration roller) in FIG. 4. FIG. 2 is a partial sectional front view around a moving guide and moving means of the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a partial cross-sectional front view around a movement guide, a release cam, and a release pin of the double-sided stencil printing apparatus in FIG. 1. FIG. 3 is a diagram for developing and explaining three printing pressure range patterns applied corresponding to a divided master-making master on a plate cylinder used in the double-sided stencil printing apparatus in FIG. 1. FIG. 2 is a perspective view showing an arrangement example of a sheet feeding start light shielding plate and a resist start light shielding plate used in the double-sided stencil printing apparatus in FIG. 1 on an end plate of a plate cylinder. FIG. 2 is a front view of a main part showing a drive mechanism of a paper feed roller and a registration roller of a paper feed unit of the double-sided stencil printing apparatus in FIG. 1. It is a front view of the principal part of the image reading part of the double-sided stencil printing apparatus in FIG. It is a top view of the principal part of the operation panel of the double-sided stencil printing apparatus in FIG. It is a block diagram which shows the structure of the control means of the double-sided stencil printing apparatus in FIG. It is the figure which showed typically the principal part structure of the double-sided stencil printing apparatus. (A) is a front view of the refeed stopper means explaining the paper abutting state, and (b) is a front view of the refeed stopper means explaining the state where the paper abutting state is released. (A) is the front view of the stopper part explaining the paper abutting state in a comparative example, (b) is the front view of the stopper part explaining the state which canceled the paper abutting state in a comparative example. It is a front view explaining the swing mechanism of the auxiliary roller. It is a front view explaining a stopper release mechanism.

Explanation of symbols

1 Plate cylinder (printing drum)
8, 8X, 8Y Master 16a Nip part 21 Press roller 29 Plate cylinder position detection sensor (Drum rotation angle information detection means)
36a Front surface printed paper 51 Auxiliary roller 52 Refeed sensor 53a Stopper surface 70 Refeed stopper means 70c Solenoid 100 Controller 105 Belt drive motor (conveyance motor)
108 Conveying belt 300 Double-sided stencil printing apparatus 350 Plate cylinder sensor 351 Rotary encoder 400 Front end detection sensor (front end detection means)

Claims (4)

A plate making unit for stencil making as a master is divided into two front and rear sides in the feeding direction of the stencil sheet, and a predetermined and printing drum rotating at a peripheral speed, rotatably installed in the press roller is pressed against the outer surface of the printing drum a drum rotation angle information detecting means for detecting the drum rotation angle information of the printing drum, the printing by the first surface in the prior SL two surfaces when printing each by the two planes by replacing the front and back of the paper to be printed a moving guide the contacts receive and hold the paper that is, a conveyor belt unit for conveying the sheet, a conveying motor which can control the feed amount and speed of the sheet by the conveying belt means, printed by the first surface after, after the temporarily stopping the progression said the sheet conveyed by the conveying belt in contact when printing the second surface, and a stopper which operates so as to release the stop, before Symbol second mark in terms And a stopper releasing mechanism for releasing the contact between the paper and the stopper at the time of, nip between the press roller and the printing drum has a city, after printing with the first surface, the second surface after temporarily stopping the progress of the paper in printing, conveys the the paper, meet duplex stencil printing device for refeeding to the printing position while reversing the front and back of the paper,
Having a leading edge detecting means for detecting the leading edge of the paper on the downstream side of the stopper;
The transport motor is a step motor controlled by subtracting the paper feed amount from the stopper to the nip part from a feed amount theoretical value indicated by the number of steps,
The transport belt is operated at a transport speed faster than the peripheral speed of the printing drum after the contact of the stopper with the paper is released,
At the time when the leading edge of the sheet transported after the release of the contact is detected by the leading edge detection means, the leading edge of the sheet from the stopper reaches the leading edge detection means . Compare the feed amount theoretical value with the feed amount actually transported and detected to find the difference in feed amount ,
Of the feeding range from the stopper to the nip portion of the paper, the remainder from the position of the leading edge detection means to the nip portion except for the stopper to the leading edge detection means is the theoretical value. together to correct the feeding amount of該残Ri using the difference of the feed amount such that,
The difference between the remaining distance from the detection position by the drum rotation angle information detection means to the nip portion and the feed amount of the stencil sheet that has been wound around the printing drum is corrected. , Comparing the remaining distance until the leading edge of the paper reaches the nip portion from the leading edge detection means ,
By making the transport speed of the transport belt equal to the peripheral speed of the printing drum when these distances are equal,
A double-sided stencil printing apparatus that controls the leading edge position of the paper so as to match the printing surface start position of the stencil sheet after the plate making. In the double-sided stencil printing apparatus according to claim 1,
A registration auxiliary roller that can be freely contacted and separated from the press roller, and when the paper leading edge position matches the printing surface start position of the stencil sheet after making a plate based on the drum rotation angle information by the drum rotation angle information detecting means, A double-sided stencil printing apparatus, wherein a resist auxiliary roller is brought into contact with the press roller. In the double-sided stencil printing apparatus according to claim 1,
After the peripheral speed of the printing drum and the transport speed of the transport belt become equal, the transport motor performs the time of the transport motor based on the output signal of the drum rotation angle information detection means by the drum rotation angle information detection means. A double-sided stencil printing apparatus characterized in that feedback control is performed to change the hit amount. In the double-sided stencil printing device according to any one of claims 1 to 3,
A double-sided stencil printing apparatus, wherein a distance between the outer periphery of the printing drum at a minimum step angle of the drum rotation angle information detecting means and a minimum feed amount of the transport motor are set to be equal or a multiple relationship.

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