JP4424052B2 - Printer - Google Patents

Description

  The present invention relates to a printer that records a color image on a recording medium.

  Various techniques are known for printers capable of recording color images on a recording medium. For example, Patent Document 1 includes three thermal heads capable of individually recording each of yellow, magenta, and cyan colors, and the three recording heads that are drawn from the recording paper roll are conveyed in the paper feeding direction. A one-pass color thermal printer that records a color image with a thermal head is disclosed.

  Patent Document 2 discloses a 3-pass color thermal printer. In such a printer, a color thermal recording paper having a length of one frame drawn from a recording paper roll is sent out so as to face one thermal head, and then a yellow image is recorded while being pulled back, and then the recording paper. Are sent and pulled back alternately, and a magenta image is recorded at the second pull back, and a cyan image is recorded at the third pull back.

Patent Document 3 is provided with three thermal heads of yellow, magenta, and cyan. After the recording paper drawn from the recording paper roll is conveyed in the paper feeding direction and the print preparation is completed, the recording paper is loaded. A one-pass color thermal printer that records a color image of one frame while being conveyed in the pull-back direction is disclosed. In such a printer, when a color image of one frame is recorded, the recording paper is conveyed again in the paper feeding direction and cut at the rear end portion of the color image. Then, the recording paper on which the color image is recorded is discharged, and the next one-frame color image is recorded while the recording paper that has been prepared for printing is conveyed in the pullback direction.
Japanese Patent Application Laid-Open No. 8-174476 JP-A-9-99572 JP 2001-246769 A

  In the printer described in Patent Document 1, a color image can be recorded only by transporting the recording paper in one direction without transporting the recording paper back and forth. However, in such a printer, when the three thermal heads are pressed against the recording paper in order from the one where the recording paper reaches the printing position, the image quality deteriorates due to load fluctuations during conveyance of the recording paper. Sometimes. Therefore, in such a printer, in order to prevent deterioration in image quality, recording of a color image is started after all three thermal heads are pressed against the recording paper. For this reason, the portion between the thermal head in the vicinity of the leading edge of the recording paper, that is, the length between the most upstream thermal head and the most downstream thermal head in the paper feeding direction from the leading edge of the recording paper is stretched between the thermal heads. Recording of a color image is started. For this reason, there is a problem in that an image is not formed in the length portion where the recording paper is stretched and a blank portion is formed.

  On the other hand, in the printers described in Patent Document 2 and Patent Document 3, a color image can be recorded even in the vicinity of the leading end of the recording paper, so that it is possible to prevent the recording paper from being wasted. Here, in the printer described in Patent Document 3, since all three thermal heads are pressed against the recording paper when the recording paper is conveyed in the pullback direction, the image quality is caused by load fluctuations during the conveyance of the recording paper. Is rarely worse.

  However, in the printer of Patent Document 2, it is necessary to repeat feeding and pulling of the recording paper three times in order to record a single color image. Further, in the printer of Patent Document 3, it is necessary to feed and pull back the recording paper once for each color image of one frame. Therefore, in order to record a color image of a plurality of frames in these printers, the reciprocating conveyance of the recording paper has to be repeated many times.

  Here, in the printers of Patent Document 2 and Patent Document 3, a pair of transport rollers is disposed between the recording paper roll and the thermal head, and the transport direction of the recording paper is switched by switching the driving direction of the pair of transport rollers. Is changed to either the paper feed direction or the pull back direction. Therefore, in order to record a color image of a plurality of m frames (m is an integer of 2 or more), the printer of Patent Document 2 must reciprocate the recording paper 3 m times, and the driving direction of the conveying roller pair is changed. It is necessary to switch only (6m-1) times. In the printer of Patent Document 3, the recording paper must be reciprocated and conveyed m times, and the driving direction of the conveying roller pair needs to be switched only (2m-1) times.

  As described above, when the driving direction of the conveying roller pair is switched, a time-related conveying loss occurs due to the switching. Therefore, if the number of times of switching the driving direction of the conveying roller pair is increased, the time-related conveying loss is increased accordingly, and the processing capability of the printer is lowered.

  In addition, when color image recording and recording paper cutting are performed in parallel, the image quality of the color image may deteriorate due to the recording paper misalignment caused by the recording paper cutting. To prevent this, even if the recording paper transport and image recording are interrupted when cutting the recording paper, if the recording paper transport and image recording are resumed after the recording paper is cut, the streak pattern appears at the image recording interruption position. As a result, the image quality deteriorates and the processing capability also decreases.

  Therefore, the main object of the present invention is to improve the processing capability when recording a plurality of color images while preventing deterioration of image quality due to waste of the recording medium and load fluctuations during conveyance of the recording medium, and recording. It is an object of the present invention to provide a printer that can prevent deterioration in image quality due to cutting of a medium.

Means for Solving the Problems and Effects of the Invention

The printer of the present invention is disposed between an image recording unit capable of recording a color image on a recording medium, a supply unit storing a long recording medium, and the image recording unit and the supply unit. A cutting unit capable of cutting the medium, and a second direction opposite to the first direction and the first direction from the supply unit toward the image recording unit while the recording medium faces the image recording unit and a transport mechanism that can be conveyed in the direction of the recording medium is the first such record media of a plurality of images recordable length is arranged on the opposite side of the supply portion to the image recording unit A slack portion in which the recording medium is loosened between the image recording section and the cutting section on the recording medium that is transported in the second direction and then transported in the second direction. A transport control hand for controlling the transport mechanism so that When the like plurality of color images by the image recording unit on the recording medium being conveyed in the second direction by the transport mechanism is recorded, and image recording control means for controlling said image recording section, the slack A cutting control means for controlling the cutting section so that the recording medium is cut by the cutting section in a state where the section is formed .

  According to this configuration, a plurality of color images can be recorded on the recording medium conveyed in the second direction after the recording medium is conveyed in the first direction from the supply unit toward the image recording unit. Therefore, a color image can be recorded in the vicinity of the leading end of the recording medium (the region from the leading end of the recording medium portion that is transported in the second direction after being transported in the first direction) and the recording medium is being transported. It is possible to prevent the image quality from deteriorating due to the load fluctuation. Further, even when a plurality of color images are recorded on the recording medium, it is only necessary to reciprocate the recording medium once, and it is only necessary to switch the conveying direction of the recording medium in the conveying mechanism once. Transport loss can be reduced. As a result, when a plurality of color images are recorded on a recording medium, it is possible to improve the processing capability of the printer while preventing deterioration in image quality due to waste of the recording medium and load fluctuations during conveyance of the recording medium.

  Further, the positional deviation of the recording medium that occurs when the recording medium is cut is absorbed by the slack portion and is not transmitted to the area facing the image recording portion. As a result, it is possible to prevent deterioration in image quality due to the displacement of the recording medium caused by the cutting of the recording medium. In addition, since it is not necessary to interrupt the conveyance of the recording medium and the image recording in the image recording unit, the processing capability is not reduced.

  In the printer of the present invention, the transport mechanism is configured to rotate the first recording roller between the cutting unit and the image recording unit while sandwiching the recording medium. A second conveyance roller pair capable of imparting a conveyance force to the recording medium by rotating while sandwiching the recording medium between the cutting unit and the first conveyance roller pair, and the conveyance control It is preferable that the means can control the first transport roller pair and the second transport roller pair independently of each other. According to this configuration, the slack portion can be easily formed.

  In the printer according to the aspect of the invention, the transport control unit may control the transport mechanism so that the transport speed of the recording medium by the second transport roller pair is faster than the transport speed of the recording medium by the first transport roller pair. It is preferable to control. According to this configuration, it is possible to prevent the slack portion from becoming too long.

  In the printer according to the aspect of the invention, it is preferable that the cutting control unit detects that a part to be cut of the recording medium has reached a cutting position by the cutting unit based on the number of rotations of the second conveying roller pair.

  In the present specification, “the number of rotations of a roller pair” means “the number of rotations of a roller pair”.

  According to this configuration, the cutting position of the recording medium can be determined with high accuracy.

  In the printer according to the aspect of the invention, the protruding position that intersects the line connecting the contact point of the first conveying roller pair and the contact point of the second conveying roller pair, and the protruding amount from the line segment are smaller than the protruding position. A pressing member that can selectively take a retracted position, a drive mechanism that moves the pressing member between the protruding position and the retracted position, and the pressing member when the length of the slack portion is equal to or less than a predetermined length. And a position control means for controlling the drive mechanism so that the pressing member moves to the retracted position when the length of the slack portion exceeds the predetermined length. It is preferable.

  The phrase “the amount of protrusion from the line segment is smaller than the protrusion position” includes both that the tip of the pressing member is on the same side as the protrusion position and the opposite side with respect to the line segment.

  According to this configuration, the bulging direction of the slack portion can always be the same direction. Therefore, it becomes easy to detect the slack portion.

  In the printer of the present invention, it is preferable that the printer further includes a detecting unit capable of detecting that the end portion in the bulging direction of the slack portion has reached a predetermined position. According to this configuration, the predetermined position is a line segment on the same side as the tip of the pressing member at the protruding position with respect to the line segment connecting the contact of the first transport roller pair and the contact of the second transport roller pair. When the positions are close, it is possible to prevent the slack portion from becoming too short. In addition, when the predetermined position is in the vicinity of the tip of the pressing member at the protruding position, it can be confirmed that the slack portion is reliably formed. Further, when the predetermined position is a position away from a line segment connecting the contact of the first transport roller pair and the contact of the second transport roller pair with respect to the tip of the pressing member at the protruding position, the slack portion is It can be prevented from becoming too long.

  In the printer according to the aspect of the invention, the pressing member may be disposed on the same side as the tip of the pressing member at the protruding position with respect to a line segment connecting the contact of the first transport roller pair and the contact of the second transport roller pair. It is preferable to further include a regulation guide for guiding the recording medium by contacting the slack portion when the member is in the protruding position. According to this configuration, since the shape of the slack portion can be made substantially constant, an error is less likely to occur in the length of the slack portion when the bulging direction end portion of the slack portion is detected.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of a printer according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of a printing unit of the printer of FIG. FIG. 3 is an enlarged view of a region surrounded by a dotted line in FIG. FIG. 4 is a diagram illustrating the movement of the conveying roller pair and the feeding roller pair of the printer of FIG. FIG. 5 is a block diagram of a main part of the printer of FIG. 1 and a control device to which these are connected.

  A thermal sublimation thermal printer 1 shown in FIG. 1 (hereinafter referred to as “printer 1”) includes an operation unit 10, a control device 20, and a printing unit 30. The operation unit 10 is for an operator to operate the printer 1 and has a display 11 for displaying various information about the printer 1 and notifying the operator. Here, in the present embodiment, a touch panel method is adopted for the operation unit 10, and an operation screen 12 including various buttons is displayed on the display 10. Accordingly, the operator can execute an operation on the printer 1 by touching the operation screen 12.

  The control device 20 receives input from the operation unit 10 and controls various operations in the printer 1. In addition, the control device 20 has a plurality of data input units 20a for acquiring print data from various storage media such as a card slot and a disk drive. The storage medium may be any medium that can store print data, such as a CD-ROM or a memory card.

  Here, the operation unit 10 and the control device 20 are fixedly arranged on the upper surface of the housing 30 a that houses the print unit 30. Here, the display surface of the display 11 of the operation unit 10 and the storage medium insertion surface of the data input unit 20a of the control device 20 substantially coincide with the front of the printer 1 (housing 30a) (the surface on the left front side in FIG. 1). ing. Therefore, it is easy for the operator heading to the front of the printer 1 to operate the display 11 and the data input unit 21.

  The housing 30a has a substantially rectangular parallelepiped shape, and the lateral width (front width) D1 is smaller than the depth D2. Therefore, the printer 1 can be installed even in a relatively narrow space. Furthermore, an opening 95 is formed on the front surface of the housing 30a for drawing out a print box 96 (described later) housed in the housing 30a to the outside of the housing 30a.

  As shown in FIG. 2, the print unit 30 includes a paper supply unit 40 that holds a paper wound in a roll shape and a paper winding unit that winds up the paper that has been unwound from the paper supply unit 40. Between the take-up unit 80 and the paper supply unit 40 and the paper take-up unit 80, there is a transport mechanism 38 that can transport the paper along a transport path curved in one direction. A cutting unit 50, an overcoat unit 60, and a printing unit 70 are disposed between the paper supply unit 40 and the paper winding unit 80 from the upstream side to the downstream side of the transport path. A print box 96 is provided near the conveyance path between the paper supply unit 40 and the cutting unit 50.

  In the present embodiment, “paper transport direction (transport direction)” means a direction from the paper supply unit 40 toward the paper winding unit 80. Further, the “paper front end” and the “image front end” mean the end on the downstream side of the paper or the image transport direction, and the “paper rear end” and “image rear end” The term “edge” means an end portion on the upstream side of the sheet or image in the conveying direction.

  The paper supply unit 40 has a magazine case 41 provided in the uppermost stream of the transport path, and a long paper is wound around the rotation shaft 43 so that the printing surface is on the outside. The wound winding part 45 is loaded. Here, the rotating shaft 43 is driven to rotate counterclockwise in FIG. 2 when the sheet is unwound from the sheet supply unit 40 and conveyed toward the downstream side in the conveying direction by the motor 43a (see FIG. 5). When the unwound paper is taken up by the paper supply unit 40, it is rotated clockwise in FIG. The rotary shaft 43 is connected to a shaft (not shown) that is rotationally driven by a motor 43a via a one-way clutch 43c having the same function as one-way clutches 34c and 35c described later.

  The transport mechanism 38 can transport the paper unwound from the paper supply unit 40 toward the downstream side in the transport direction and wind it around the paper winder 80, and is temporarily wound into the paper winder 80. The paper unwound from the paper take-up unit 80 can be fed back toward the upstream side in the transport direction while the paper is unwound again.

  The conveyance mechanism 38 is disposed in the vicinity of the paper supply unit 40, and includes a pair of paper supply rollers 31 that can send out the paper from the paper supply unit 40 and rewind the paper to the paper supply unit 40, and the paper supply roller It is disposed between the pair 31 and the cutting unit 50 and is disposed between the turn roller pair 32 that changes the conveyance direction of the sheet conveyed upward and between the cutting unit 50 and the overcoat unit 60. The slack forming roller pair 33 and the transport roller pair 34 that can be transported while sandwiching the paper, and the paper that is disposed downstream of the print unit 70 in the transport direction and is transported downstream of the print unit 70 in the transport direction And a feed roller pair 35 for feeding the paper into the paper winding unit 80. In this embodiment, the paper feed roller pair 31, the turn roller pair 32, and the feed roller pair 35 are made of resin rollers, and the slack forming roller pair 33 and the transport roller pair 34 are made of metal rollers. It is configured.

  Here, the paper feed roller pair 31, the turn roller pair 32, the slack forming roller pair 33, the transport roller pair 34, and the feed roller pair 35 have a circumference having a predetermined radius (indicated by a two-dot chain line in FIG. 2). It is arranged along. As can be seen from FIG. 2, the head portions 61 and 71 to 73 of the overcoat portion 60 and the printing portion 70 are also arranged along the circumference, and the paper supply portion 40 and the paper take-up portion 80 are It arrange | positions inside the said periphery.

  The paper feed roller pair 31, the slack forming roller pair 33, the transport roller pair 34, and the feed roller pair 35 are connected to motors 31a, 33a34a, 35a (see FIG. 5) controlled by the transport control unit 27a (see FIG. 5), respectively. It can be driven to rotate.

  Here, the movement of the conveyance roller pair 34 and the feeding roller pair 35 will be described in detail with reference to FIG. 4A shows the movement of the transport roller pair 34 and the feed roller pair 35 when the paper is transported downstream in the transport direction, and FIG. 4B shows the paper on the upstream side in the transport direction. The movement of the conveying roller pair 34 and the feeding roller pair 35 during reverse feeding is shown. As shown in FIG. 4, the conveyance roller pair 34 includes a driving roller 34d and a driven roller 34e. The drive roller 34d is connected to a shaft 34b that is rotationally driven by a motor 34a via a one-way clutch 34c. Similarly, the feed roller pair 35 includes a drive roller 35d and a driven roller 35e, and the drive roller 35d is connected to a shaft 35b that is rotationally driven by a motor 35a via a one-way clutch 35c.

  Since the one-way clutches 34c and 35c have the same function, the function of the one-way clutch 34c will be described here. The one-way clutch 34c is fixed to the driving roller 34d and rotates together with the driving roller 34d. When the drive roller 34d rotates faster than the rotational speed of the shaft 34b, the rotational force of the shaft 34b is not transmitted to the drive roller 34d, and the drive roller 35d rotates idly with respect to the shaft 34b. In other cases, the rotational force of the shaft 34b is transmitted to the drive roller 34d via the one-way clutch 34c, and the shaft 34b and the drive roller 34d rotate together.

  Therefore, when the conveyance roller pair 34 holds the sheet, the conveyance speed of the sheet is slower than the conveyance speed of the sheet based on the rotational force of the conveyance roller pair 34 driven by the motor 34a. Is transmitted to the conveying roller pair 34. Then, the sheet is transported with a transport force applied by the transport roller pair 34. On the other hand, when the paper conveyance speed is faster than the paper conveyance speed based on the rotational force of the conveyance roller pair 34 driven by the motor 34a, the driving force of the motor 34a is not transmitted to the conveyance roller pair 34 and is conveyed. The roller pair 34 is idle. That is, the transport roller pair 34 is driven to rotate at a rotational speed corresponding to the paper transport speed.

  Here, the sheet conveying speed based on the rotational force of the conveying roller pair 34 driven by the motor 34a is V1, and the sheet conveying speed based on the rotational force of the feeding roller pair 34 driven by the motor 35a is V2. Consider the case of transporting a sheet downstream in the transport direction with reference to (a). At this time, as will be described later, after the leading edge of the paper reaches the feed roller pair 35 and is nipped, the drive of the transport roller pair 34 is stopped, and the transport speed V1 becomes zero. On the other hand, the feed roller pair 35 is rotationally driven by the driving force of the motor 35a being transmitted through the shaft 35b and the one-way clutch 35c. Since the sheet sandwiched between the transport roller pair 34 is transported at the transport speed V2, the transport roller pair 34 is idled by the function of the one-way clutch 34c.

  Next, with reference to FIG. 4B, consider a case where the paper is fed back upstream in the transport direction. At this time, as will be described later, since the driving of the feed roller pair 35 is stopped, the conveyance speed V2 becomes zero. On the other hand, the conveying roller pair 34 is rotationally driven by the driving force of the motor 34a being transmitted through the shaft 34b and the one-way clutch 34c. Then, the sheet sandwiched by the pair of feed rollers 35 is reversely fed at the conveyance speed V1, and therefore the pair of feed rollers 35 is idled by the function of the one-way clutch 35c.

  The pair of paper feed rollers 31 is also connected to a shaft (not shown) that is rotationally driven by a motor 31a through a one-way clutch 31c having the same function as the one-way clutches 34c and 35c described above.

  Next, the configuration of the slack forming roller pair 33 will be described. The slack forming roller pair 33 includes a driving roller 33d and a driven roller 33e (see FIG. 3). The drive roller 33d is connected to a shaft (not shown) that is rotationally driven by the motor 33a without passing through a one-way clutch. The driven roller 33e can be advanced and retracted with respect to the paper transport path by an elevating mechanism 33f (see FIG. 5). Therefore, the driven roller 33e has a pressure-bonding position (a position indicated by a solid line in FIG. 3) for nipping the sheet with the drive roller pair 33d and a retracted position (a position indicated by a one-dot chain line in FIG. 3) for nipping the sheet. It can be taken selectively.

  Further, the printing unit 30 includes an encoder 36 that can detect the rotation speed of the slack forming roller pair 33 and an encoder 37 that can detect the rotation speed of the conveyance roller pair 34. Here, as described above, the transport roller pair 34 is driven and rotated by the motor 34a to transport the paper, and is driven and rotated along with the paper transported by the feed roller pair 35. obtain. The encoder 37 can detect the number of rotations of the conveyance roller pair 34 even when the second conveyance roller 34 is in any of the above states.

  In addition, as illustrated in FIG. 3, a pressing member 39 is disposed between the slack forming roller pair 33 and the conveyance roller pair 34 of the printing unit 30. The pressing member 39 is a line segment A (see FIG. 5) that connects the contact of the slack forming roller pair 33 and the contact of the transport roller pair 34 by an elevating mechanism 39a (see FIG. 5) controlled by the position control unit 27c (see FIG. 5). 3)). Specifically, the pressing member 39 intersects with the line segment A and protrudes upward at the leading end to push the paper upward (a position indicated by a one-dot chain line in FIG. 3). A retracted position (position indicated by a solid line in FIG. 3) located in the vicinity of A can be selectively taken. Further, in the vicinity of the line segment A on the same side as the tip of the pressing member 39 that is in the protruding position with respect to the line segment A, the guide 39b that comes into contact with the sheet when the pressing member 39 is in the protruding position is a slack forming roller pair. It is provided in the vicinity of 33 and in the vicinity of the transport roller pair 34.

  The cutting portion 50 is disposed between the turn roller pair 32 and the slack forming roller pair 33. The cutting unit 50 includes a rolling cutter 51 disposed above the conveyance path, a fixed blade 52 disposed below the conveyance path, and a chip box 53.

  The rolling cutter 51 has a disk shape, and a blade is formed on the entire circumference of the rolling cutter 51. The center of the rolling cutter 51 is held by a shaft 51a. The rolling cutter 51 is connected to a drive mechanism 55 (see FIG. 5) controlled by the cutting control unit 27d via a shaft 51a. The drive mechanism 55 rotates and drives the rolling cutter 51 via the shaft 51a, and moves forward or backward along the sheet conveyance path along a direction orthogonal to the sheet (in the direction orthogonal to the paper surface in FIG. 2). . On the other hand, the fixed blade 52 is a rectangular blade that is disposed so as to be orthogonal to the paper transport path and is longer than the entire width of the paper transport path.

  Accordingly, when the cutting control unit 27d controls the drive mechanism 55 and moves the rolling cutter 51 along the width direction of the paper while rotating the paper while the paper is arranged at the cutting position by the cutting unit 50, the rolling cutter The sheet is cut by the interaction between 51 and the fixed blade 52. In the printer 1 according to the present embodiment, as will be described later, the cutting unit 50 cuts the paper at the leading edge and the trailing edge of each image.

  The chip box 53 is disposed below the rolling cutter 51 and the fixed blade 52. Accordingly, when the paper is cut at the leading edge or the trailing edge of each image and the blank portion between the images is cut, the blank portion is stored in the chip box 53.

  The overcoat unit 60 is disposed on the downstream side of the conveyance roller pair 34 in the conveyance direction. The overcoat part 60 has one head part 61. The head unit 61 is for performing a colorless and transparent overcoat (OC) on the surface of the paper on which an image is printed. Thus, by overcoating the surface of the paper, the light resistance of the image printed on the paper can be improved and the surface of the paper can be protected. Further, by selecting the material of the overcoat, the gloss of the print can be improved and a high-quality print can be provided.

  The printing unit 70 is disposed between the overcoat unit 60 and the feed roller pair 35. The printing unit 70 has three head units 71 to 73. The head portions 71 to 73 are for performing printing corresponding to cyan (C), magenta (M), and yellow (Y), respectively. Here, in the printer 1, a head unit 71 corresponding to cyan, a head unit 72 corresponding to magenta, and a head unit 73 corresponding to yellow are provided in this order from the upstream side in the transport direction to the downstream side in the transport direction. In the printer 1, the transport roller pair 34 is disposed on the upstream side in the transport direction of the overcoat unit 60 and the printing unit 70, and the feed roller pair 35 is disposed on the downstream side in the transport direction.

  In the printer 1 of the present embodiment, when the paper unrolled from the paper supply unit 40 is conveyed toward the downstream side in the conveyance direction, the overcoat in the overcoat unit 60 and the color image in the printing unit 70 are performed. Is not performed, and when the paper once wound on the paper take-up unit 80 disposed on the downstream side in the transport direction from the print unit 70 is fed back toward the upstream side in the transport direction, the print unit 70 The printing of the image at and the overcoat at the overcoat unit 60 are performed. Accordingly, the printer 1 can print a color image in the order of yellow, magenta, and cyan on the paper surface, and can further overcoat the paper surface on which the color image is printed.

  In the printing unit 70, a plurality of images are sequentially printed on the paper from the upstream side to the downstream side in the transport direction. Here, in the present embodiment, the first image, the second image, the third image,...

  Next, a schematic configuration of the head units 61 and 71 to 73 will be described. In addition, since the structure of the head parts 61 and 71 to 73 is the same, only the head part 73 will be described in detail here.

  The head unit 73 includes a thermal head 73a having a large number of heating elements (not shown) arranged over the entire width of the paper conveyance path, and a tip portion of the thermal head 73a (in the vicinity of the paper conveyance path and the heating elements are arranged). A platen roller 73b facing the other end, a tape-like ribbon 73c having an ink area to which ink corresponding to yellow is attached, a ribbon supply roller 73d around which a ribbon 73c before printing is wound, and a post-printing ribbon A ribbon take-up roller 73e for taking up the ribbon 73c.

  Here, the thermal head 73a can be moved back and forth with respect to the paper transport path by an elevating mechanism 73f (see FIG. 5). Therefore, the thermal head 73a can selectively take the print position where the ribbon 73c and the paper are pressed against each other and the retracted position where the paper 73 is not pressed between the vicinity of the tip and the platen roller 73b.

  In the head unit 73, when the paper is conveyed between the thermal head 73a and the platen roller 73b in a state where the thermal head 73a is disposed at the printing position, the ink of the ribbon 73c heated by the thermal head 73a. Thus, a color image corresponding to yellow can be printed on the paper. At this time, when the sheet is conveyed between the thermal head 73a and the platen roller 73b, the ribbon 73c is also moved from the ribbon supply roller 73d toward the ribbon take-up roller 73e as the sheet is conveyed. Sent.

  The head unit 61 and the head units 71 and 72 are similar to the head unit 73 in that the thermal heads 61a, 71a and 72a, the platen rollers 61b, 71b and 72b, the ribbons 61c, 71c and 72c, and the ribbon supply roller 61d. 71d, 72d, ribbon take-up rollers 61e, 71e, 72e, and elevating mechanisms 61f, 71f, 72f, respectively.

  Here, in the head unit 61 and the head units 71 and 72, ink corresponding to colorless and transparent, cyan and magenta, respectively, instead of the tape-like ribbon 73c having an ink region to which ink corresponding to yellow of the head unit 73 is attached. Tape-shaped ribbons 61c, 71c, and 72c having an ink region to which are attached are used.

  A pair of guides 75 a to 75 c are disposed between the head portion 61 of the overcoat portion 60 and the head portions 71 to 73 of the printing portion 70, respectively. Each of the pair of guides 75a to 75c includes two plate-like members, and guides the sheet (mainly the leading end portion of the sheet) conveyed between the head units 61 and 71 to 73, respectively. is there. Accordingly, the pair of guides 75a to 75c are arranged so as to face each other with a predetermined interval across the sheet conveyance path.

  The paper take-up unit 80 has a storage case 81 provided on the most downstream side of the transport path. The storage case 81 has a substantially cylindrical shape, and a part of the storage case 81 opens as a paper insertion opening 82. In the present embodiment, as shown in FIG. 2, the central angle of the portion that becomes the insertion port 82 is about 90 degrees, and one edge 82a is in the vicinity of the left end of the storage case 81, and the other The edge portion 82 b is in the vicinity of the upper end portion of the storage case 81.

  Here, the feeding roller pair 35 is disposed in the vicinity of the upper portion of the edge portion 82 a of the storage case 81, and the sheet conveyed downward by the feeding roller pair 35 is located in the storage case 81 from the vicinity of the end portion 82 a of the insertion port 82. Inserted into. The paper inserted into the paper winding unit 80 is guided by contacting the inner peripheral surface of the storage case 81. As a result, in the storage case 81, the paper is wound in order from the leading edge of the paper so that the printing surface becomes the outer surface according to the curl of the paper. The storage case 81 is rotatably provided with four winding rollers 83a to 83d. A part of each of the winding rollers 83 a to 83 d protrudes inward from the inner peripheral surface of the storage case 81. Accordingly, since the frictional force when the paper comes into contact with the inner peripheral surface of the storage case 81 is reduced, the paper is prevented from being damaged.

  The print box 96 stores paper (print) on which each color image printed by the cutting unit 50 is printed after the image is printed in the printing unit 70 and the overcoat unit 60 is overcoated. Is. The print box 96 is a box-shaped member having an upper end opened, and is supported by a support shaft 97 at the lower end to be rotatable. Accordingly, the print box 96 has a state in which the print box 96 is housed in the housing 30a (shown by a solid line in FIG. 2) and an upper end portion of the print box 96 through the opening 95 provided on the front surface (right surface in FIG. 2). A state in which the vicinity is pulled out of the housing 30a (a state indicated by a broken line in FIG. 2) can be taken. Therefore, the operator can easily take out the paper on which each color image is printed by pulling out the upper end portion of the print box 96 from the front of the printer 1 (housing 30a).

  A sorting mechanism (not shown) is provided above the print box 96 so as to be close to the transport path upstream of the turn roller pair 32 in the transport direction. In this sorting mechanism, the paper is fed back toward the upstream side in the conveyance direction when the paper is wound around the paper supply unit 40 and when the paper on which each color image is printed is discharged to the print box 96. It is possible to switch the paper transport path when printing. Therefore, by controlling the sorting mechanism, only the paper on which each color image is printed can be stored in the print box 96.

  Further, an image detection sensor 90 that can detect an end portion (mainly a rear end portion of the image) of an image printed on a sheet conveyed along the conveyance path, on the upstream side of the cutting unit 50 in the conveyance direction. Is provided. Further, a paper detection sensor 91 capable of detecting the edge of the paper is provided upstream of the overcoat unit 60 in the transport direction. In the present embodiment, the end of the overcoat unit 60 on the upstream side in the conveyance direction and the detection position by the paper detection sensor 91 substantially coincide with each other. In addition, a position detection sensor 92 that can detect that the tip of the pressing member 39 has reached the protruding position is provided in the vicinity of the tip of the pressing member 39 at the protruding position.

  As shown in FIG. 4, the control device 20 includes a motor 43 a that drives the rotation shaft 43 of the paper supply unit 40, a paper feed roller pair 31, a slack forming roller pair 33, a transport roller pair 34, and a feed roller pair 35. Motors 31 a, 33 a, 34 a, 35 a to be driven, an elevating mechanism 33 f of a driven roller 33 e of the slack forming roller pair 33, an encoder 36 for detecting the rotation speed of the slack forming roller pair 33, and the rotation speed of the conveying roller pair 34 An encoder 37 for detecting the pressure, a lifting mechanism 39a for the pressing member 39, a driving mechanism 55 for the rolling cutter 51 for the cutting part 50, a thermal head 61a for the overcoat part 60 and the printing part 70, and a lifting mechanism 61f for 71a to 73a, 71f-73f and drivers 61g, 71g-73g, image detection sensor 90, paper detection sensor 91, position detection A sensor 92, an operation unit 10 are connected.

  The control device 20 includes hardware such as a CPU, a ROM, and a RAM controlled by appropriate software, and includes a maximum winding amount storage unit 21, a print information storage unit 22, and a necessary winding amount calculation unit. 23, a comparison unit 24, a winding amount determination unit 25, a conveyance amount detection unit 26, a conveyance control unit 27a, a print control unit 27b, a position control unit 27c, and a cutting control unit 27d. Yes.

  The maximum winding amount storage unit 21 maximizes the maximum length of paper that can be transported downstream in the transport direction from the printing unit 70 when the paper is transported from the paper supply unit 40 toward the paper winding unit 80. It is stored as the winding amount. The maximum winding amount is determined by the length of the conveyance path between the printing position by the head unit 73 arranged on the most downstream side in the conveyance direction of the printing unit 70 and the insertion port 82 of the sheet winding unit 80, and the sheet winding. This value is calculated by adding together the length of paper that can be taken up in the storage case 81 of the unit 80. The maximum winding amount is input to the maximum winding amount storage unit 21 by the operator.

  Here, the maximum winding amount largely varies depending on the size of the storage case 81. The length of paper that can be wound in the storage case 81 may be the maximum length of paper that can actually be stored in the storage case 81, or the maximum length of paper that can be stored in the storage case 81. It may be shorter than the length and can be set arbitrarily. Therefore, in the present embodiment, the length of the paper that can be wound in the storage case 81 used when the maximum winding amount is calculated is that the paper is not damaged or scratched in the storage case 81. The length of the range is set to be shorter than the maximum length of paper that can be stored in the storage case 81.

  The print information storage unit 22 stores various setting values when a color image is printed. Here, the set values include the print length of one frame for each print type (the length in the transport direction), the number of prints (the number of frames), the length of the margin formed between adjacent images, and the head heat dissipation. Includes additional length. As the print length of one frame for each print type, a plurality of values are stored for each of a plurality of print types such as a standard size and a panorama size, for example. As the number of prints, a value input for each order by the operator before printing is stored. Further, the length of the margin between the images and the additional length for heat radiation of the head are stored as values input by the operator before starting printing. The additional length is such that the temperatures of the thermal heads 71a, 72a, 73a that have generated heat for printing an image and the thermal head 61a that has generated heat for overcoating are substantially the same as the ambient temperature after energization. The sheet is set to such a length that the sheet faces each of the thermal heads 61a and 71a to 73a. In the present embodiment, the time required for each of the thermal heads 61a, 71a to 73a that have generated heat to be substantially the same as the ambient temperature, and the sheet to be fed back toward the upstream side in the transport direction. The additional length is calculated by the product with the conveyance speed.

  Here, the “order” indicates a range that is handled as one unit when a plurality of color images are printed by the printer 1. For example, in the printer 1, when a plurality of color images corresponding to an order from one customer are handled as one unit, the order from this one customer becomes one order, and the order from a plurality of customers When a plurality of corresponding color images are handled as one unit, orders from these customers are combined into one order. In addition to the case where one or a plurality of orders for each customer is one order as described above, when the operator supplies a print command for printing a plurality of color images to the printer 1, the print The order is one order.

  The necessary winding amount calculation unit 23 calculates the length of paper necessary for printing all of a plurality of color images included in one order as the necessary winding amount. In other words, in order to print all of a plurality of color images included in one order, before the printing of the color image by the printing unit 70, paper having a length capable of printing these color images is printed on the printing unit. It is necessary to carry the sheet downstream in the carrying direction from 70. Therefore, when the paper is conveyed from the paper supply unit 40 toward the paper take-up unit 80, the printing position by the head unit 73 of the printing unit 70 is used to print all of the plurality of color images included in one order. The length of the paper to be transported exceeding this is calculated as the required winding amount.

  Here, the necessary winding amount will be described with reference to FIG. FIG. 6 is a diagram illustrating a state in which a plurality of color images included in one order are printed in the vicinity of the leading end of the paper. FIG. 6 shows a case where six images of the same print type are included in one order. As shown in FIG. 6, an area corresponding to the additional length z for heat radiation of the head is provided in the vicinity of the front end (left end portion in FIG. 6) of the sheet, and from there toward the upstream side (right side in FIG. 6) The area corresponding to the print length x and the area corresponding to the margin length y are alternately provided by the number n of prints.

Accordingly, in the necessary winding amount calculation unit 23, when the print type and the number of prints of a color image included in one order are input by the operator before the start of printing, each value stored in the print information storage unit 22 is set. Based on this, the required winding amount L corresponding to one order is calculated by the following equation.
L = z + x * n + y * (n-1)

  The comparison unit 24 compares the required winding amount calculated by the required winding amount calculation unit 23 with the maximum winding amount stored in the maximum winding amount storage unit 21. Then, the comparison unit 24 obtains a comparison result regarding the magnitude relationship between the required winding amount and the maximum winding amount.

  The winding amount determination unit 25 is actually conveyed downstream of the printing unit 70 in the conveyance direction before the conveyance direction of the sheet is changed from the direction toward the downstream side in the conveyance direction to the direction toward the upstream side in the conveyance direction. The length of the sheet (actual winding amount), that is, the length of the sheet that is actually conveyed beyond the position facing the head unit 73 of the printing unit 70 is determined. Here, the winding amount determination unit 25 determines the winding amount based on the comparison result by the comparison unit 24. That is, when the comparison unit 24 obtains a comparison result that the required winding amount is equal to or less than the maximum winding amount, the winding amount determination unit 25 determines the actual winding amount as the necessary winding amount, On the other hand, when the comparison unit 24 obtains a comparison result that the required winding amount is longer than the maximum winding amount, the actual winding amount is determined as the maximum winding amount.

  The carry amount detection unit 26 detects the carry amount of the sheet based on the number of rotations of the slack forming roller pair 33 and the carry roller pair 34 detected by the encoders 36 and 37. For example, the conveyance amount detection unit 26 determines the conveyance direction from the detection position by the paper detection sensor 91 based on the number of rotations of the conveyance roller pair 34 detected by the encoder 36 after the paper detection sensor 91 detects the leading edge of the paper. The length of the sheet conveyed downstream is detected. As a result, the conveyance amount detection unit 26 is conveyed downstream of the printing unit 70 in the conveyance direction before the sheet conveyance direction is changed from the direction toward the downstream side in the conveyance direction to the direction toward the upstream side in the conveyance direction. The length of the paper can be detected. As will be described later, when the paper is transported downstream in the transport direction, after the leading edge of the paper reaches the feed roller pair 35, the transport force applied from the transport roller pair 34 is not used. The sheet is conveyed by the applied conveying force. Even in this case, the conveyance amount detection unit 26 always detects the conveyance amount of the sheet based on the number of rotations of the conveyance roller pair 34.

  The transport amount detection unit 26 can detect the transport amount of the paper not only when the paper is transported toward the downstream side in the transport direction but also when the paper is fed back toward the upstream side in the transport direction. it can. For example, if the paper transport direction is changed from the direction downstream in the transport direction to the direction upstream in the transport direction, the transport direction is changed from the transport amount downstream in the transport direction before the transport direction is changed. The leading end position of the sheet can be detected by subtracting the transport amount upstream in the transport direction after being performed.

  The conveyance control unit 27a includes motors 43a, 31a, 33a, 34a, and 35a that drive the rotation shaft 43, the pair of paper feed rollers 31, the pair of slack forming rollers 33, the pair of conveyance rollers 34, and the pair of feed rollers 35, and a pair of slack formation rollers. By controlling the lifting mechanism 33f of the driven roller 33e of 33, the sheet is conveyed from the sheet supply unit 40 toward the sheet take-up unit 80, and a slack is formed between the cutting unit 50 and the overcoat unit 60. At the same time, the paper is fed back from the paper take-up unit 80 toward the paper supply unit 40.

  Here, the function of the conveyance control unit 27a will be described in more detail. First, when the paper is fed from the paper supply unit 40 and conveyed downstream in the conveying direction, the elevating mechanism 33f is controlled so that the driven roller 33e of the slack forming roller pair 33 is in the retracted position, and the motor 33a Stop driving. That is, the slack forming roller pair 33 does not apply a conveying force to the paper. The driving of the motor 34a is stopped until the leading end of the sheet passes through the conveying roller pair 34 and reaches the sheet detection sensor 91, and compared with the sheet feeding speed based on the rotational force of the rotating shaft 43. The motors 43a and 31a are controlled so that the paper conveyance speed based on the rotational force of the paper feed roller pair 31 is increased. At this time, due to the functions of the one-way clutches 43c, 31c, and 34c, the rotating shaft 43 and the conveyance roller pair 34 are idle, and the paper feed roller pair 31 is driven by the motor 31a. Accordingly, the sheet is transported by the transport force applied from the pair of sheet feed rollers 31.

  Thereafter, the motors 43a and 31a are stopped driving until only the motor 34a is driven until the leading edge of the sheet is nipped by the feed roller pair 35. At this time, due to the functions of the one-way clutches 43c, 31c, and 34c, the rotating shaft 43 and the paper feed roller pair 31 are idle, and the transport roller pair 34 is driven by the motor 34a. Accordingly, the sheet is transported only by the transport force applied from the transport roller pair 34.

  When the leading edge of the sheet is sandwiched between the feed roller pair 35, the driving of the motors 43a, 31a, and 34a is stopped, and only the motor 35a is driven. At this time, due to the functions of the one-way clutches 43c, 31c, 34c, and 35c, the rotary shaft 43, the paper feed roller pair 31, and the transport roller pair 34 are idle, and the feed roller pair 35 is driven by the motor 35a. Accordingly, the sheet is transported only by the transport force applied from the transport roller pair 35.

  Next, the function of the conveyance control unit 27a when the sheet is fed back toward the upstream side in the conveyance direction will be described with reference to FIG. 7 showing the movement of the slack forming roller pair 33 and the conveyance roller pair 34. When the paper is fed back toward the upstream side in the transport direction, the driving of the motor 35a is always stopped and the paper transport speed V3 (see FIG. 7) due to the rotational force of the transport roller pair 34 is constant. The motor 34a is driven so that the conveyance speed of the sheet nipped by the conveyance roller pair 34 is controlled not to be faster than V3. Therefore, by the function of the one-way clutches 34c and 35c, the transport roller pair 34 is always driven by the motor 34a, and the feed roller pair 35 is idling. Therefore, description of the control of the motors 34a and 35a will be omitted hereinafter.

  First, as shown in FIG. 7A, based on the rotational force of the rotary shaft 43 until the rear end portion (the portion indicated by Z <b> 1 in FIG. 7) of the first image reaches the cutting position by the cutting portion 50. The motors 43a and 31a are controlled so that the paper transport speed based on the paper rewinding speed and the rotational force of the paper feed roller pair 31 is equal to the paper transport speed V3 based on the rotational force of the transport roller pair 34. At this time, the rotary shaft 43 and the paper feed roller pair 31 are driven by the motors 43a and 31a, respectively, by the functions of the one-way clutches 43c and 31c. Further, the elevating mechanism 33f is controlled so that the driven roller 33e of the slack forming roller pair 33 is in the retracted position, and the driving of the motor 33a is stopped. Therefore, the sheet is fed back by the conveying force applied from the rotating shaft 43, the sheet feeding roller pair 31 and the conveying roller pair 34.

  When the rear end portion Z1 of the first image reaches the cutting position by the cutting portion 50, as shown in FIG. 7B, the lifting mechanism 33f is moved so that the driven roller 33e of the slack forming roller pair 33 is in the pressure-bonding position. While controlling, the drive of motor 43a, 31a, 33a is stopped. Accordingly, the conveyance of the sheet upstream of the slack forming roller pair 33 in the conveyance direction is stopped, and the sheet downstream of the conveyance roller pair 34 in the conveyance direction is reversely fed by the conveyance force applied from the conveyance roller pair 34. . As a result, as shown in FIG. 7C, the sheet is slackened between the slack forming roller pair 33 and the conveying roller pair 34.

  As will be described later, when the cutting control unit 27d detects that a predetermined length of slack has been formed by the detection signal from the position detection sensor 92, the rear end Z1 of the first image is moved by the cutting unit 50. Disconnected. The one-way clutches 43c and 31c are controlled by controlling the motors 43a and 31a so that the sheet rewinding speed based on the rotational force of the rotating shaft 43 and the sheet conveying speed based on the rotational force of the pair of paper feed rollers 31 are equal. With this function, the rotation shaft 43 and the paper feed roller pair 31 are driven by the motors 43a and 31a, and the paper upstream of the cutting position in the transport direction is rewound to the paper supply unit 40.

  Here, the slack of a predetermined length in the present embodiment is the length of slack formed when the pressing member 30 is in the protruding position with the paper pressed. The predetermined length is the trailing edge of the color image adjacent to the downstream side in the transport direction of the color image after the trailing edge of the color image is cut after the slack of the predetermined length is formed and the trailing edge of the color image is cut. However, the length is set such that the slack does not disappear until the cutting position by the cutting portion 50 is reached.

  Further, after the rear end portion Z1 of the first image is cut, until the tip end portion (the portion indicated by Z2 in FIG. 7) reaches the cutting position by the cutting portion 50, as shown in FIG. In addition, the motor 33 a is controlled so that the paper transport speed V 4 (see FIG. 7) based on the rotational force of the slack forming roller pair 33 is faster than the paper transport speed V 3 based on the rotational force of the transport roller pair 34. Accordingly, the sheet on the upstream side of the conveying roller pair 34 in the conveying direction is fed back by the conveying force applied from the slack forming roller pair 33. On the other hand, the sheet on the downstream side of the conveyance roller pair 34 in the conveyance direction is reversely fed only by the conveyance force applied from the conveyance roller pair 34. Therefore, the slack formed between the slack forming roller pair 33 and the transport roller pair 34 is reduced.

  Thereafter, when the leading end Z2 of the first image reaches the cutting position by the cutting unit 50, the driving of the motor 33a is stopped. Accordingly, as shown in FIG. 7E, the conveyance of the sheet upstream of the slack forming roller pair 33 in the conveyance direction is stopped, and the sheet downstream of the conveyance roller pair 34 in the conveyance direction is conveyed to the conveyance roller pair 34. The feed force is reversed. At this time, the leading end Z2 of the first image is cut.

  After the front end portion Z2 of the first image is cut, until the rear end portion (the portion indicated by Y1 in FIG. 7) of the second image reaches the cutting position by the cutting portion 50, FIG. As shown in the drawing, the motor 33 a is controlled so that the paper transport speed V 4 based on the rotational force of the slack forming roller pair 33 is faster than the paper transport speed V 3 based on the rotational force of the transport roller pair 34. Accordingly, the sheet on the upstream side of the conveying roller 34 in the conveying direction is fed back by the conveying force applied from the slack forming roller pair 33. On the other hand, the sheet on the downstream side of the conveyance roller pair 34 in the conveyance direction is reversely fed only by the conveyance force applied from the conveyance roller pair 34. Therefore, the slack formed between the slack forming roller pair 33 and the transport roller pair 34 is reduced.

  Next, when the rear end Y1 of the second image reaches the cutting position by the cutting unit 50, the driving of the motor 33a is stopped. Accordingly, as shown in FIG. 7G, the conveyance of the sheet upstream of the slack forming roller pair 33 in the conveyance direction is stopped, and the sheet downstream of the conveyance roller pair 34 in the conveyance direction is conveyed by the conveyance roller pair 34. The feed force is reversed. Then, the slack formed between the slack forming roller pair 33 and the transport roller pair 34 becomes large again. Thereafter, when the slack of a predetermined size is formed, the rear end Y1 of the second image is cut by the cutting unit 50.

  Thereafter, the conveyance control unit 27a controls the motor 33a so that the slack forming roller pair 33 repeats the operations shown in FIGS. 7D to 7G, thereby downstream of the conveyance roller pair 34 in the conveyance direction. The sheet on the side is conveyed at a constant speed V3, and the sheet is fed back upstream in the conveying direction while forming a slack between the pair of slack forming rollers 33 and the pair of conveying rollers 34.

  The printing control unit 27b controls the raising / lowering timing and printing timing of the thermal head 61a of the overcoat unit 60 and the thermal heads 71a to 73a of the printing unit 70. Specifically, when the paper is transported downstream in the transport direction, the print control unit 27b sets the thermal heads 61a and 71a to 73a to the retracted position, and before the paper is fed back upstream in the transport direction, The raising / lowering timing is controlled so that the thermal heads 61a, 71a to 73a are set to the printing positions. In addition, the print control unit 27b prints a plurality of color images included in one order separated by the length of the blank portion on the paper that has been fed back upstream in the transport direction, and finally, The printing timing is controlled so that the image is not printed in an area corresponding to the additional length on the leading end side of the paper than the printed color image. Further, the print control unit 27b controls the overcoat unit 60 so as to overcoat only the area where the color image of the paper is printed.

  The position control unit 27 c controls the raising / lowering timing of the pressing member 39. Specifically, the position control unit 27 c keeps the pressing member 39 in the retracted position until the rear end of the color image printed on the paper reaches the cutting position by the cutting unit 50. Then, after the rear end portion of the color image reaches the cutting position by the cutting section 50, the lifting mechanism 39a is controlled to move the pressing member 39 from the retracted position to the popping position. At this time, the moving speed of the pressing member 39 is controlled by the function of the one-way clutch 34c so that the conveyance roller pair 34 does not idle. Thereafter, when the position detection sensor 92 detects that the pressing member 39 has reached the pop-out position, the pressing member 30 is returned to the retracted position by controlling the lifting mechanism 39a.

  The cutting control unit 27d detects that the trailing end and the leading end of the color image, which are the cut positions of the paper, have reached the cutting position by the cutting unit 50, and controls the cutting timing at the cutting unit 50.

  Specifically, the conveyance roller pair 34 detected by the encoder 37 after the conveyance direction of the sheet detected by the conveyance amount detection unit 26 is changed from the direction toward the downstream side in the conveyance direction to the direction toward the upstream side in the conveyance direction. The cutting control unit 27d detects that the trailing edge of the first image has reached the cutting position by the cutting unit 50 based on the sheet conveyance amount based on the number of rotations. Further, after the trailing edge of the color image is detected by the image detection sensor 90 detected by the conveyance amount detection unit 26, the conveyance amount of the paper based on the number of rotations of the slack forming roller pair 33 detected by the encoder 36 is used. The cutting control unit 27d detects that the leading end of the color image has reached the cutting position by the cutting unit 50. Further, after the sheet is cut at the leading end of the color image detected by the conveyance amount detection unit 26, the cutting control unit is determined from the conveyance amount of the sheet based on the number of rotations of the slack forming roller pair 33 detected by the encoder 36. 27d detects that the rear end portion of the color image printed on the downstream side in the transport direction from the first image has reached the cutting position by the cutting section 50.

  Then, the cutting control unit 27d detects that the rear end portion of the color image has reached the cutting position by the cutting unit 50, and then the position detection sensor 92 causes the pressing member 39 to reach the pop-out position, so that the predetermined length is reached. When it is detected that slack has been formed, the cutting unit 50 is controlled so that the paper is cut at the rear end of the color image. When the cutting control unit 27d detects that the leading end of the color image has reached the cutting position by the cutting unit 50, the cutting control unit 27d controls the cutting unit 50 so that the sheet is cut at the leading end of the color image.

  Next, the operation when the printer 1 prints an image will be described with reference to FIG. FIG. 8 is a flowchart showing an operation procedure for printing an image in the printer 1.

  First, the leading end of the sheet unwound by rotating the rotary shaft 43 from the paper winding unit 45 loaded in the paper supply unit 40 is transported only by the transport force applied from the paper feed roller pair 31. (Step S101). Then, the conveyance by the paper feed roller pair 31 is continued until the leading edge of the paper passes through the conveyance roller pair 34 and reaches the paper detection sensor 91 (step S102). Here, when the leading edge of the sheet is detected by the sheet detection sensor 91, a detection signal indicating that the leading edge of the sheet has been detected is transmitted from the sheet detection sensor 91 to the control device 20.

  In this way, when the leading edge of the paper reaches the paper detection sensor 91, the conveyance of the paper is stopped and a standby state is entered (step S103). At this time, if the thermal heads 61a and 71a to 73a are arranged at the print positions, the thermal heads 61a and 71a to 73a are moved to the retracted positions (step S104).

  Thereafter, when an order is received from the operator and the print type and the number of prints of color images included in one order are input (step S105), the print information is stored as preparation for starting the conveyance of the paper. Based on the information stored in the unit 22, the necessary winding amount corresponding to the one order is calculated by the necessary winding amount calculation unit 23 (step S106). Then, the required winding amount is compared with the maximum winding amount stored in the maximum winding amount storage unit 21 by the comparison unit 24 (step S107). Based on the comparison result, the winding amount determination unit 25 determines the actual winding amount (step S108). In this way, after completion of the sheet conveyance preparation, the sheet is conveyed only by the conveyance force applied from the conveyance roller pair 34 (step S109). At this time, both the rotation shaft 43 and the paper feed roller pair 31 of the paper supply unit 40 are rotatable.

  Thereafter, in a state in which the thermal heads 61a and 71a to 73a are disposed at the retracted positions, the leading end of the sheet passes through the overcoat unit 60 and the print unit 70 without performing overcoat and image printing, and the feed roller The conveyance is continued only by the conveyance force applied from the conveyance roller pair 34 until the pair 35 is reached (step S110). When the leading edge of the sheet reaches the nipping roller pair 35 and is nipped, the sheet is thereafter conveyed only by the conveying force applied from the feeding roller pair 35 and is wound from the leading edge of the sheet. Are sequentially fed into the storage case 81 of the unit 80 (step S111). At this time, as the paper is fed into the storage case 81, the leading edge of the paper is guided to the inner peripheral surface of the storage case 81 and the take-up rollers 83 a to 83 d, and the paper is wound around the curl in the storage case 81. Therefore, it is wound up. When the leading edge of the paper reaches the feed roller pair 35, the transport roller pair 34 is accompanied by the paper transported by the feed roller pair 35 from the state in which the transport force is applied to the paper by the function of the one-way clutch 34c. It is switched to the state of driven rotation.

  Thereafter, when the sheet having the length of the winding amount determined by the winding amount determination unit 25 is conveyed downstream in the conveyance direction from the printing position by the head unit 73, the winding of the sheet is finished, The conveyance of the sheet from the sheet supply unit 40 toward the sheet winding unit 80 is stopped (step S112). That is, the conveyance amount detection unit 26 detects the conveyance amount of the paper detected based on the number of rotations of the conveyance roller pair 34 detected by the encoder 37 after the paper detection sensor 91 detects the leading edge of the paper. When the winding amount determined by the amount determination unit 25 and the length of the conveyance path in the overcoat unit 60 and the printing unit 70 are added, the conveyance control unit 27a finishes winding the sheet. Then, the conveyance of the sheet to the downstream side in the conveyance direction is stopped. At this time, the rear end portion of the first image, which is an image printed on the most upstream side in the conveyance direction, of the sheet having the winding amount is disposed at the printing position by the head unit 73.

  Then, the thermal head 61a of the overcoat unit 60 and the thermal heads 71a to 73a of the printing unit 70 are simultaneously moved from the retracted position to the printing position (step S113). Thereafter, the sheet is fed back toward the upstream side in the transport direction by the transport force applied from the pair of paper feed rollers 31 and the pair of transport rollers 34 (step S114). Accordingly, at this time, the pair of paper feed rollers 31 and the pair of transport rollers 34 that have been driven to rotate are rotationally driven in the direction of transporting paper toward the upstream side in the transport direction, and the pair of feed rollers 35 The function of the clutch 35c causes the driven rotation. Further, the rotation shaft 43 of the paper supply unit 40 is rotationally driven in a direction to rewind the paper into the magazine case 41.

  Then, while the paper is being fed back toward the upstream side in the conveyance direction, for each color image included in one order, printing corresponding to yellow by the head unit 73, printing corresponding to magenta by the head unit 72, and printing by the head unit 71 Printing corresponding to cyan is sequentially performed. In this way, each color image is printed in the order of yellow, magenta, and cyan, thereby completing the color image (step S115). Subsequently, overcoating is performed on the surface of the paper on which the color image is printed by the head unit 61 (step S116).

  In the present embodiment, when the necessary winding amount is shorter than the maximum winding amount, reverse feeding to the upstream side in the sheet conveyance direction is started, and simultaneously printing of a color image is started. All of the color images included in the order are printed intermittently so that a margin of a predetermined width is formed between the images. On the other hand, when the necessary winding amount is longer than the maximum winding amount, the reverse feeding to the upstream side in the sheet conveyance direction is started, and at the same time, the printing of the color image is started, and the color image included in one order. Are intermittently printed so that a margin of a predetermined width is formed between the images. That is, as described above, a color image is printed on the paper so that the image areas and the margins are alternately arranged. However, no image is printed in an area corresponding to the additional length for heat radiation near the leading edge of the paper. And in the printing part 70, when there exists an image area | region at the same timing in the position facing at least 2 of the three head parts 71-73, printing is simultaneously performed by those head parts. In addition, the overcoat in the overcoat unit 60 is performed in parallel with the printing of the color image in the print unit 70. In this way, in the printing unit 70 and the overcoat unit 60, a plurality of printable sheets can be printed on the paper having the winding amount determined by the winding amount determination unit 25 or the paper having the maximum winding amount. The color image is printed and overcoated.

  Thus, the paper on which printing and overcoat have been performed for a plurality of color images is cut for each image by the cutting unit 50 in the procedure described in detail later. Then, after the leading edge of the final image printed closest to the leading edge of the sheet is cut, it is determined whether or not printing of all color images included in one order has been completed (step S117). . If it is determined that printing of all the color images included in one order has not been completed, the process returns to step S106 and the same processing as described above is repeated. On the other hand, when it is determined that all the printing of the color images included in one order has been completed, the process ends.

  Note that when it is determined in step S117 that all printing of color images included in one order has not been completed, for example, the comparison unit 24 determines that the necessary winding amount is longer than the maximum winding amount. This is a case where the winding amount determination unit 25 determines the maximum winding amount as the final winding amount. That is, in this case, printing of the remaining color images that could not be printed on the sheet having the maximum winding amount among the color images included in one order is continued. In this way, the same processing as described above is repeated until all the printing of the color images included in one order is completed.

  Next, an operation when the paper is cut in the printer 1 will be described with reference to FIG. FIG. 9 is a flowchart showing an operation procedure for cutting a sheet on which an image has been printed.

  In step S116 of the above-described image printing operation procedure, after overcoating is performed on the surface of the sheet on which the color image is printed, the conveying force continuously applied from the paper feed roller pair 31 and the conveying roller pair 34 is continuously applied. As a result, the sheet is fed backward toward the upstream side in the transport direction. Then, when the rear end portion of the first image (which coincides with the rear end portion of the paper having the length of the winding amount determined by the winding amount determination unit 25) reaches the cutting position by the cutting unit 50. (Step S201), the driven roller 33e of the slack forming roller pair 33 disposed at the retracted position is disposed at the pressure bonding position (Step S202). Note that the timing at which the trailing edge of the color image reaches the cutting position by the cutting unit 50 is detected based on the carry amount detected by the carry amount detection unit 26. At this time, the reverse feeding of the sheet upstream of the slack forming roller 33 in the conveying direction is stopped, and the sheet downstream of the conveying roller 34 in the conveying direction is reversely fed only by the conveying force applied from the conveying roller pair 34. The Accordingly, a slack is formed between the slack forming roller pair 33 and the transport roller pair 34. Further, at this time, the pressing member 39 arranged at the retracted position starts to move to the protruding position (step S203).

  Thereafter, when the position detection sensor 92 detects that the pressing member 39 has reached the pop-out position and the slack of a predetermined length is completed (step S204), the press member 39 arranged at the pop-out position is returned to the retracted position. (Step S205). At this time, the paper is cut at the rear end of the color image (step 206). Then, after the paper is cut in this way, the paper on which the image upstream of the most upstream color image in the transport direction is not formed (the length of the winding amount determined by the winding amount determination unit 25). The sheet upstream of the trailing edge of the sheet in the transport direction) is rewound to the sheet supply unit 40.

  Next, driving of the slack forming roller pair 33 is started (step S207). Accordingly, the sheet upstream of the conveyance roller pair 34 in the conveyance direction is reversely fed by the conveyance force applied from the slack forming roller pair 33, and the sheet downstream of the conveyance roller pair 34 in the conveyance direction is conveyed from the conveyance roller pair 34. Reverse feed is performed only with the given conveying force. At this time, since the conveyance control unit 27a controls the conveyance speed of the sheet upstream of the conveyance roller pair 34 in the conveyance direction to be higher than the conveyance speed of the downstream sheet, the slack is small. Become.

  When the rear end portion of the image upstream in the conveyance direction reaches the detection position by the image detection sensor 90, a detection signal indicating that the rear end portion of the image has been detected is transmitted from the image detection sensor 90 to the control device 20. Is done. Then, after the trailing edge of the image is detected by the image detection sensor 90, the transport amount detection unit 26 detects the sheet upstream in the transport direction based on the number of rotations of the slack forming roller pair 33 detected by the encoder 36. Detect the transport amount. Based on the transport amount, the cutting control unit 27d detects that the leading end of the color image has reached the cutting position by the cutting unit 50. At this time, the driving of the slack forming roller pair 33 is stopped. Accordingly, the backward feeding of the sheet is stopped upstream of the slack forming roller pair 33 in the transport direction, and the sheet is cut at the leading end of the color image (step S208). In this way, the paper from which the leading edge and trailing edge of the color image are cut is stored in the print box 96.

  Whether or not the color image printed on the cut paper is the final image printed closest to the front edge of the paper each time the paper is cut at the front edge of the color image Is determined (step S209). If it is determined that the image is not the final image, the driving of the slack forming roller pair 33 is started again. Then, the conveyance amount detection unit 26 cuts the sheet at the leading end of the color image, and then, based on the number of rotations of the slack forming roller pair 33 detected by the encoder 36, the sheet to the upstream side in the conveyance direction. Detect the transport amount. Then, based on the transport amount by the cutting control unit 27d, the rear end portion of the color image adjacent to the color image whose front end portion is cut in step S208 on the downstream side in the transport direction reaches the cutting position by the cutting unit 50. It is detected that this has occurred (step S210). At this time, the drive of the slack forming roller pair 33 is stopped, whereby the reverse feeding of the sheet upstream of the slack forming roller pair 33 in the transport direction is stopped (step S211). Accordingly, the slack formed between the slack forming roller pair 33 and the conveying roller pair is increased again. Then, it returns to step S203 and the process similar to the above is repeated.

  On the other hand, if it is determined in step S209 that the image is the final image, the paper cutting procedure ends, and the process proceeds to step S117 of the above-described image printing operation procedure.

  As described above, in the printer 1 according to the present embodiment, after the paper is transported in the direction from the paper supply unit 40 to the paper winding unit 80, the upstream side in the transport direction from the overcoat unit 60 and the printing unit 70. A plurality of color images can be printed on a sheet that is reversely fed toward the upstream side in the conveyance direction by a conveyance force applied from the arranged conveyance roller pair 34. For this reason, it is possible to print a color image in an area from the front end of the paper portion that is reversely fed after conveyance, and to suppress deterioration in image quality due to load fluctuations during conveyance of the paper. Further, even when printing a plurality of color images on paper, it is only necessary to reciprocate the paper once, and it is only necessary to switch the paper transport direction in the transport mechanism 38 once. Loss can be reduced. As a result, when printing a plurality of color images on paper, the processing capability of the printer 1 can be improved while preventing deterioration of image quality due to paper waste and load fluctuations during paper transport.

  Further, the positional deviation of the paper that occurs when the paper is cut in the cutting unit 50 is absorbed by the slack and is not transmitted to the region facing the printing unit 70. As a result, it is possible to prevent deterioration in image quality due to the positional deviation of the paper caused by the cutting of the paper. In addition, when a color image is printed on the paper in the printing unit 70, the paper on the downstream side of the transport roller pair 34 in the transport direction is always fed back by the transport force applied from the transport roller pair 34. . Accordingly, it is not necessary to interrupt the reverse feeding of the paper and the printing of the color image in the printing unit 70, so that the processing capacity is not reduced.

  Further, a slack forming roller pair 33 that can be rotationally driven by a motor 33a and a transport roller pair 34 that can be rotationally driven by a motor 34a are arranged between the cutting part 50 and the overcoat part 60 in order from the upstream side in the transport direction. Has been. The motors 33a and 34a are independently controlled by the transport control unit 27a. Therefore, slack can be easily formed.

  Further, after the sheet is cut at the rear end portion of the color image, until the leading end portion of the image reaches the cutting position by the cutting portion 50 and after the sheet is cut at the leading end portion of the color image, the next image Until the trailing end of the paper reaches the cutting position by the cutting unit 50, the sheet conveyance speed by the slack forming roller pair 33 is controlled to be higher than the sheet conveyance speed by the conveyance roller pair 34. Therefore, it is possible to prevent the slack from becoming too long.

  In addition, the cutting control unit 27d is the paper cut position based on the rotation speed of the conveyance roller pair 34 detected by the encoder 37 or the rotation speed of the slack forming roller pair 33 detected by the encoder 36. It is detected that the leading end and the trailing end of the color image have reached the cutting position by the cutting unit 50. Therefore, the cut position of the paper can be determined with high accuracy.

  The pressing member 39 can be moved between the pop-out position and the retracted position by the lifting mechanism 39a. The elevating mechanism 39a moves the pressing member 39 to the protruding position from the retracted position after the trailing end of the color image reaches the cutting position by the cutting section 50 and the driving of the slack forming roller pair 33 is stopped. After the slack of a predetermined length is formed, the position controller c is controlled to return the pressing member 30 from the protruding position to the retracted position. Therefore, the bulging direction of the slack can always be the same direction, and the slack can be easily detected.

  Further, a position detection sensor 92 that can detect that the pressing member 39 has reached the pop-out position is provided. Therefore, it can be confirmed that the slack of the predetermined length is reliably formed.

  Further, in the vicinity of the line segment A on the same side as the tip of the pressing member 39 that is in the protruding position with respect to the line segment A, the guide 39b that comes into contact with the sheet when the pressing member 39 is in the protruding position is a slack forming roller pair. It is provided in the vicinity of 33 and in the vicinity of the transport roller pair 34. Therefore, since the shape of the slack can be made almost constant, when the position detection sensor 92 detects that the pressing member 39 has reached the pop-out position, an error is unlikely to occur in the length of the slack formed. Become.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. Is something. For example, in the above-described embodiment, the pair of slack forming rollers 33 that can be rotationally driven by the motor 33a and the pair of conveyance rollers 34 that can be rotationally driven by the motor 34a can be loosened between two roller pairs that can be controlled independently of each other. However, the present invention is not limited to this, and the slack forming roller pair 33 and the conveying roller pair 34 may be driven to rotate by one motor.

  In addition, in the above-described embodiment, after cutting the trailing edge of the color image, until the leading edge of the image reaches the cutting position, and after cutting the leading edge of the color image, The case where the sheet conveyance speed by the slack forming roller pair 33 is controlled to be higher than the sheet conveyance speed by the conveyance roller pair 34 until the trailing end reaches the cutting position has been described. Is not limited. The sheet conveyance speed by the slack forming roller pair 33 may be controlled to be always lower than the sheet conveyance speed by the conveyance roller pair 34.

  Furthermore, although the above-mentioned embodiment demonstrated the case where slack was formed by stopping the drive of the slack formation roller pair 33, it is not restricted to this. For example, the slack may be formed by driving the slack forming roller pair 33 so that the sheet conveying speed by the slack forming roller pair 33 is slower than the sheet conveying speed by the conveying roller pair 34.

  In the above-described embodiment, the case where the slack of the predetermined length is formed after the trailing edge of the color image printed on the paper has reached the cutting position has been described. Is not limited to this. It is sufficient that a slack is formed between the cutting part 50 and the overcoat part 60 when the paper is cut.

  Further, in the above-described embodiment, the cutting control unit 27d uses the rotation number of the conveying roller pair 34 detected by the encoder 37 or the rotation number of the slack forming roller pair 33 detected by the encoder 36 to change the sheet. Although the case where it is detected that the leading end portion and the trailing end portion of the color image that are the to-be-cut positions have reached the cutting position by the cutting portion 50 has been described, the present invention is not limited thereto. For example, a sensor provided at a cutting position by the cutting unit 50 may detect that the cut position of the paper has reached the cutting position by the cutting unit 50.

  Furthermore, although the above-mentioned embodiment demonstrated the case where the press member 39 which can take a retracted position and a pop-out position selectively was arrange | positioned, the press member 39 does not need to be.

  Moreover, although the above-mentioned embodiment demonstrated the case where the position detection sensor 92 was able to detect that the press member 39 reached | attained the popping-out position, it is not restricted to this. The position detection sensor 92 may be able to detect that the front end of the pressing member 39 has reached a position close to the line segment A on the same side as the front end of the pressing member 39 in the protruding position with respect to the line segment A. Then, it may be possible to detect that the end portion in the bulging direction of the slack portion has reached a position farther from the line segment A than the tip end of the pressing member at the protruding position. Further, the position detection sensor 92 may not be provided.

  In addition, in the present embodiment, a guide 39b that contacts the slack portion when the pressing member 39 is in the protruding position is disposed on the same side as the tip of the pressing member 39 that is in the protruding position with respect to the line segment A. However, the guide 39b may not be provided.

Furthermore, in the above-described embodiment, in the thermal sublimation printer 1, a color image is printed by the three head portions 71 to 73 that come into contact with the recording medium, but the printer can record a color image. If so, the configuration of the image recording unit is not limited to this. Therefore, it may be a thermal printer (including a thermal transfer system and a thermal recording system) having a head that comes into contact with a recording medium, and has, for example, an inkjet head, a FOCRT (Fiber Optic Cathode-Ray-Tube), a laser light source, etc. And a printer capable of recording a color image without contacting the recording medium. Further, the image recording unit does not necessarily have a plurality of image recording heads, and may have only one image recording head capable of recording a color image. Therefore, for example, it has three inkjet heads each having nozzles capable of ejecting yellow, magenta and cyan inks, and these heads reciprocate in a direction crossing the recording medium conveyance direction to record a color image. Or a single inkjet head having nozzles capable of discharging yellow, magenta, and cyan inks, and the head reciprocates in a direction intersecting the recording medium conveyance direction. A printer that records a color image may be used.

1 is an external perspective view of a printer according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a schematic configuration of an image forming unit of the printer of FIG. 1. FIG. 3 is an enlarged view of a region surrounded by a dotted line in the image forming unit in FIG. 2. It is a figure showing a motion of the conveyance roller pair of the printer of FIG. 1, and a sending roller pair. It is a block diagram about the principal part of the printer of FIG. 1, and the control apparatus to which these were connected. It is a figure which shows a mode when the several color image contained in 1 order is printed in the front-end | tip part vicinity of a paper. FIG. 2 is a diagram illustrating movements of a slack forming roller pair and a conveyance roller pair when the printer of FIG. 1 cuts a sheet. 3 is a flowchart showing an operation procedure in the printer 1. 3 is a flowchart illustrating an operation procedure for cutting a sheet in the printer.

Explanation of symbols

1 Thermal printer (printer)
DESCRIPTION OF SYMBOLS 10 Operation part 20 Control apparatus 21 Maximum winding amount memory | storage part 22 Print information storage part 23 Required winding amount calculation part 24 Comparison part 25 Winding amount determination part 26 Conveyance amount detection part 27a Conveyance control part (conveyance control means)
27b Print control unit (image recording control means)
27c Position control unit (position control means)
27d Cutting control unit (cutting control means)
30 Print unit 33 Slack forming roller pair (second roller pair)
34 Transport roller pair (first roller pair)
36, 37 Encoder 38 Conveying mechanism 39 Pressing member 39a Elevating mechanism (driving mechanism)
39b Guide (Regulation Guide)
40 Paper supply unit (supply unit)
50 Cutting unit 60 Overcoat unit 70 Printing unit (image recording unit)
71a to 73a Thermal head 80 Paper winding unit 91 Paper detection sensor 95 Opening

Claims (7)

An image recording unit capable of recording a color image on a recording medium;
A supply unit storing a long recording medium;
A cutting unit that is disposed between the image recording unit and the supply unit and capable of cutting the recording medium;
A transport mechanism capable of transporting a recording medium in a first direction from the supply unit toward the image recording unit and a second direction opposite to the first direction while facing the image recording unit;
The second after the plurality of images are conveyed recording medium in the first direction so that the recording medium of the recordable length is arranged on the opposite side of the supply portion to the image recording unit The transport mechanism is formed so that a slack portion in which the recording medium is loosened is formed between the image recording section and the cutting section on the recording medium transported in the second direction. Conveyance control means for controlling;
Image recording control means for controlling the image recording unit so that a plurality of color images are recorded by the image recording unit on a recording medium conveyed in the second direction by the conveyance mechanism;
A printer comprising: a cutting control unit that controls the cutting unit so that the recording medium is cut by the cutting unit in a state where the slack portion is formed . The transport mechanism is
A first conveying roller pair capable of imparting a conveying force to the recording medium by rotating while sandwiching the recording medium between the cutting unit and the image recording unit;
A second conveying roller pair capable of imparting a conveying force to the recording medium by rotating while sandwiching the recording medium between the cutting portion and the first conveying roller pair;
The transport control means is
The printer according to claim 1, wherein the first conveyance roller pair and the second conveyance roller pair can be controlled independently of each other.   The transport control unit controls the transport mechanism so that a transport speed of the recording medium by the second transport roller pair is faster than a transport speed of the recording medium by the first transport roller pair. The printer according to claim 2.   The said cutting control means detects that the to-be-cut | disconnected location of the recording medium reached | attained the cutting position by the said cutting part based on the rotation speed of the said 2nd conveyance roller pair. The printer described. Select a projecting position that intersects a line connecting the contact point of the first transport roller pair and the contact point of the second transport roller pair, and a retracted position in which the projecting amount from the line segment is less than the projecting position. A pressing member that can be
A drive mechanism for moving the pressing member between the protruding position and the retracted position;
When the length of the slack portion is equal to or less than a predetermined length, the pressing member moves to the protruding position, and when the length of the slack portion exceeds the predetermined length, the pressing member moves to the retracted position. The printer according to claim 2, further comprising a position control unit that controls the drive mechanism.   6. The printer according to claim 5, further comprising detection means capable of detecting that an end portion in the bulging direction of the slack portion has reached a predetermined position.   The pressing member is located at the protruding position on the same side as the tip of the pressing member at the protruding position with respect to a line segment connecting the contact point of the first conveying roller pair and the contact point of the second conveying roller pair. 7. The printer according to claim 5, further comprising a regulation guide for guiding the recording medium by contacting the slack portion at a certain time.

Images