JPS5931067B2 - copying device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer type image forming apparatus that forms, develops, and transfers an electrostatic latent image. However, the electrophotographic copying device of this embodiment solves these problems in service maintenance and is inexpensive and has a high level of connectivity. It provides equipment.

Conventionally, photosensitive drums have stopped at fixed positions.

Therefore, the effects of corona charging and static electricity removal during photosensitive drum processing, as well as the effects of dirt and light leakage caused by the cleaner while the photosensitive drum is stopped, may accumulate in the same area. The same part of the body may also be physically transformed. The present invention eliminates the above drawbacks, and includes a reusable endless rotating body, forming an electrostatic latent image on the rotating body, and developing the latent image.
a plurality of process means for transferring the developed image onto a transfer material and cleaning the rotary body; a driving means for rotating the rotary body for latent image formation, development, transfer, and cleaning; and a drive means for rotating the rotary body for latent image formation, development, transfer, and cleaning; In order to determine the stop timing of the rotating body, count the clock signals whose number is a constant ratio to one rotation of the rotating body, and at the timing of the clock signal that is different from the number corresponding to one rotation of the rotating body. A first counting means for outputting a count signal, a second counting means for counting a clock signal and outputting a count signal to determine the timing of starting a process, and a second counting means for stopping the rotating body at a position different from an initial stop position. a first control means for controlling the rotation 1 driving means to stop based on the count signal of the first counting means; and a second control means for controlling the rotation 1 drive means to stop the rotation 1 driving means based on the count signal of the first counting means; The present invention provides an image forming apparatus having a second control means for controlling one of the process means according to the count signal.

As a result, the stop position and start position of the drum shift from moment to moment, which can avoid the cumulative effect mentioned above, and the entire length of the photoconductor can be used evenly, extending the lifespan of the photoconductor. Contribute. Another feature is that an endless photoreceptor is used to provide a more effective control method. When an endless photoreceptor is used, the return time of the document table or optical system becomes a total loss time. Therefore, in order to increase copying efficiency, the above-mentioned quick reversal is indispensable, and in addition, regarding the control of the copying cycle, it is necessary to change the home position of the drum for each rotation of the photosensitive drum, as in the case of conventional edged photosensitive drums. Controlling the installation cycle is extremely wasteful. For this reason, the apparatus of the present invention employs an endless photosensitive drum, and has a noggle generating device from a photosensitive drum drive device at regular intervals corresponding to the rotation of the photosensitive drum, and generates pulses and related pulses. A feature is that each cycle is controlled by a counter device. For example, the clock pulse generator is configured to generate 15.75 pulses per rotation of the drum. By doing this, when the counter counts 16 clock pulses, the drum can make one complete revolution and slightly overturn. This eliminates the unprocessed portion of the photoreceptor before and after the copying cycle in the pre- or post-processing steps described below, and therefore allows the copying process to be started from any part of the photoreceptor, which is an advantage of the endless drum. make it possible. (Pre-treatment) 1) Pre-exposure: The photoreceptor has different photosensitivity characteristics depending on its prior history of light irradiation, and therefore the sensitivity of the photosensitive plate is different between the first copy and the second copy.

Therefore, by uniformly exposing the photoreceptor to light prior to forming a latent image on the photoreceptor, the characteristics of the photoreceptor become the same between the first sheet and subsequent copies due to the fatigue effect of the photoreceptor. 2) Furthermore, as described below, if the toner is left unattended after copying, toner may stick to the contact area between the cleaning blade and the photoreceptor, and in this case, it may be necessary to clean this prior to the copying cycle. .

(Post-processing) Since the photoreceptor receives high-voltage charging with various potentials,
The surface potential and polarity of each part of the photoreceptor are different, and if discharge occurs in this state, it will adversely affect the characteristics of the drum, so it is desirable to eliminate the surface charge by, for example, an AC corona at the end of the copying cycle.

Another feature of the illustrated example of the copying apparatus is that the copy cycle is not controlled by rotation of a drum or related control means as in the past, but by controlling the copy size of the document table or optical system. This is based on an inversion signal and is performed in combination with a clock normal and a counter.It is an effective circuit system that can also reset the inversion signal of the document table or optical system or the clock pulse counter at the end of post-rotation. In order to improve reliability, we use a digital circuit to improve reliability, and also switch the number of blackouts depending on the copy size, and use this and a signal from a copy paper detector installed at the exit of the fuser to prevent copy paper delays. An extremely simple and effective circuit is used as a jam detection means for monitoring stagnation.

Furthermore, even if the power switch is turned off during the post-processing period, a means for retaining the power until the post-processing is completed is provided by a non-contact circuit, and the entire control circuit also uses non-contact type elements. In combination with the digital circuit, reliability can be increased and lifespan can be extended.

In addition, instead of the microswitch that has been conventionally used in many devices of this type, a non-contact type position detection device using a magnetic detection element is often used.

These are a liquid level detector, a clock pulse generator, a copy command button, a copy port home position paper feed start timing signal generator, a B5 size inversion position, and an A
4 size reversal position B4 size reversal position All of these used in the position detection devices in 3 have a magnet attached to the movable part, and changes in the magnetic flux intensity due to the movement of the magnet can be detected at a specific position by changes in the resistance of the semiconductor due to the Hall effect or magnetism. By using this in a detection device that uses this effect, the following effects can be obtained. First of all, contact type elements such as micro switches and reed relays,
Compared to position detection devices using contact type elements or pairs of light-emitting/receiving elements that use light as a medium, it has the advantages of no contact failure, rough installation accuracy, and dirt from toner, etc., resulting in improved reliability and longer life. It becomes possible to Furthermore, as will be described later, in this example, the
Since a digital IC is applied to the circuit, one advantage of the above-mentioned device, which serves as a source of various signals, is that it does not cause a chattering phenomenon. In this circuit, digital I
C is used to improve the size and reliability of conventional relay-centered control circuits, as well as flexibility for complex sequences. Furthermore, the reliability of the switching elements for energizing each terminal element in accordance with the control signal is improved by using semiconductor switching elements such as thyristors and transistors instead of the conventional relay-based switching elements. As is well known, digital 1C and semiconductor switching elements have a great effect on relays because they are free from the disadvantages of relays, such as contact failure, large size, and high cost. The present invention uses non-contact non-contact type elements and other solid-state elements as described above to more effectively combine these elements as a control circuit in each of the circuits shown below, thereby solving some of the problems unique to conventional copying machines. can be solved, and a more reliable copying machine control circuit can be constructed. Next, the operation of the copying machine will be explained with reference to FIGS. 1 and 2.

The copying machine of this embodiment employs a digital circuit and is controlled by clock pulses, thereby making it possible to fully utilize the features of this machine as will be described later.

First, when the main switch 10 is set to 0N, since a digital circuit is used, a very short time (approximately 1 second in this case) has elapsed due to the reset of the controller part and the start-up of other electrical systems, and then the photosensitive drum, which will be described later, is activated. 15 starts rotating.

As mentioned above, a clock pulse generation mechanism is provided in a part of the drive system to generate clock pulses approximately 16 times per rotation of the photosensitive drum. When the photosensitive drum 15 begins to rotate, the drum rotates approximately once for the first 16 clock pulses (hereinafter referred to as 16CPetc). This can be thought of as a preliminary step to the copying process, and is intended to obtain high-quality copies when the copying process begins, and can be omitted in some cases. Here, if the copy button 13 is not turned ON, the photosensitive drum will stop after making almost one revolution, but if the copy button 13 is turned ON, the copying process will proceed directly. First, when the copy button 13 is turned ON, the photosensitive drum 15 rotates by an amount of 4 CP in addition to the previous 16 CP, and only then does the document table 2 with the document placed on the document table glass 5 start, and is illuminated by the illumination lamp 16. After that, an image is formed on the drum 15 at the exposure section 19 using the reflecting mirror 17 and the in-mirror lens 18 . The surface of the photosensitive drum 15, that is, the photosensitive layer covered with a transparent insulating layer, is first charged to + by a corona current from a positive charger 21 which supplies a high voltage of + from a high voltage power supply 20.

Subsequently, when reaching the exposure section 19, the image of the subject illuminated by the illumination lamp 16 is slit-exposed onto the photosensitive drum 15, as described above. At the same time, AC high voltage is being supplied from the high voltage power supply 20. A by AC charger 22
C-charged. Then, a high-contrast electrostatic latent image is formed on the drum surface by full-face exposure using the full-face exposure lamp 23, and the next development process begins.
The developing device 24 includes a container 26 that holds the developer 25, a pump 27 that stirs the developer and pushes it up to the developing electrode section, a developing electrode 28, and a device for removing fog when there is a fog on the image developed on the drum. To do this, it consists of an electrode roller 29 that rotates in close proximity to the drum and one end of which is grounded. The developing electrode 28 is always kept at a constant distance from the photosensitive drum 15, and the electrostatic latent image formed on the photosensitive drum 15 is absorbed by the developer 25 pushed up onto the developing electrode 28 by the pump 27. It is developed with toner and visualized. Next, the photosensitive drum 15 is charged with a high voltage by the post charger 30 from the high voltage power source 20, and the excess developer on the photosensitive drum 15 is squeezed out without disturbing the image. Next, the transfer paper 7 fed from the paper feed section is brought into close contact with the photosensitive drum 15, and the image on the photosensitive drum 15 is transferred onto the transfer 7 by the electric field generated by the high voltage from the high power source 20 by the transfer charger 31. Ru. After the transfer, the transfer paper 7 is separated by a separation belt 32 and sent to the dry fixing section 3.
I am guided by 3. The remaining toner developer on the photosensitive drum 15 is wiped off by the edge portion 35 of the blade cleaner 34 that is pressed against it, and the next cycle is repeated again. The developer wiped by the blade cleaner 34 is guided to the developing device 24 through grooves 36 provided at both ends of the photosensitive drum 15 (FIG. 3) and used again for development. Here, the main switch 1 mentioned earlier
0 to 0N, the drum rotates by an amount equivalent to 16CP, part 1
To explain why the document table 2 starts to move only after the drum has rotated by 6CP + 4CP, this machine uses an endless type photosensitive drum, and therefore no image can be formed on any surface of the photosensitive drum. We are now able to contribute to

However, if you want to increase the number of copies per unit time by eliminating unnecessary rotations as much as possible, first of all, if there is any residual toner on the blade cleaner edge 35c for the first rotation of the drum, this machine should be operated. For example 1
This is because, in the worst case, the photosensitive drum may dry out and stick to the drum when it is not used for more than a week or 10 days, and in that case, it is necessary to clean the photosensitive drum before forming a latent image. Next is the 4CP portion, which is due to the fact that in the copying process mentioned earlier, there are 10 charging processes etc. before the slit exposure, and the cleaner edge part mentioned above is added to the first sheet. This process is based on the fact that avoiding this when copying will make the machine more reliable.

Next, the transfer paper 7 is stored in the force set 6, and by fitting the force set 6 into the paper feed section at the bottom left of the machine, the force set 6, which is removably attached, can be loaded according to the size of several types of transfer paper. Various types are available and can be easily replaced as required.

The transfer paper 7 is placed on the middle plate 37 in the force set 6, and by pushing up the middle plate 37 upwardly by the spring 38, the transfer paper 7 is always separated by the separating claws 3 provided on both sides of the tip of the force set 6.
It's being pushed to 9.

At this time, by appropriately selecting the spring constant of the spring 38, the force with which the transfer paper 7 is pressed against the paper feed roller 40 during paper feeding can be kept almost constant regardless of the amount of transfer paper 7 in the force set 6. There is. When the document table reaches a predetermined position, an operating piece fixed to the document table activates the detection means on the main body side and outputs a signal, causing the constantly rotating paper feed roller 40
descends and contacts the uppermost transfer paper in the force set 6, and by movement with the separating claw 39, one sheet of transfer paper is separated and sent out from the force set 6.

However, the register rollers 41 and 42 in the immediate vicinity are
Since the paper feed roller 40 stops descending at the same time, force set 6
The transfer paper 7 fed out from the transfer paper 7 creates a slack between the guides 43 and 44 with its leading edge touching the contact portions of the register rollers 41 and 42. Then, when the paper feed roller is about to rise, the register rollers 41 and 42 rotate again in time with the leading edge of the image on the photosensitive drum, and the transfer paper 7 is sent at a speed that matches the circumferential speed of the photosensitive drum 15. . Then, as mentioned above, the transfer paper 7 comes into close contact with the photosensitive drum 15,
The image on the drum 15 is transferred onto the transfer paper 7 by the transfer charger 30, and the transferred paper 7 is transferred to the drum 1 by the separation belt 32.
The toner on the transfer paper 7 is separated from the paper 5, passes through a drying fixing section 30, is fixed on the transfer paper 7, and is discharged onto a discharge tray 47 by discharge rollers 45 and 46.

Next, the operation for copying will be explained using FIGS. 2, 3, and 3.

Place the document to be copied on the platen glass 5 with its leading edge aligned with the leading edge A of the glass, press it with the cover 3 (Fig. 2), and press the copy button 13 (Fig. 2). starts rotating and at the same time starts operating. The document table 2 moves to the left in FIG. 1 in synchronization with the circumferential speed of the photosensitive drum 15 in response to a document table start signal after 4CP from the clock pulse generating mechanism, and performs slit exposure. When the exposure is completed, the document table 2 stops moving to the left and immediately returns to the opposite direction, that is, to the right, in response to a signal from the document table 2 itself according to the paper size in the force set. The time required for this return is loss time during copying, so it is desirable that it be short. In this machine, the return speed is approximately four times the forward speed to increase copying efficiency. Because the return speed is fast like this, it is easy to cause a shock when stopping, but this machine uses the brake mechanism described later to absorb the shock.
The document table 2 is quickly stopped at a predetermined position. Even when a large number of copies are to be made continuously from the same document, this can be easily done by using a counting device (not shown) that is linked to the copy button 13. The counting device detects the movement of the original platen 2, performs counting, and holds the switch element until the set number of sheets has been counted, so that a large number of copies can be made. The document table restart command during continuous copying is issued by 1CP after the document table 2 has stopped at a predetermined home position.

This is to ensure that the document table 2 moves smoothly when it starts moving forward. In addition, the copying machine of this embodiment can print from the maximum B4 size to the minimum B4 size.
Copies can be made in various sizes up to 5 sizes. In such a case, if the document table 2 were to move a distance of B4, which is the maximum copy size, for any copy size, the number of copies per unit time would be small, resulting in a large time loss. Therefore, this copying machine has a plurality of document table reversal signal generating members 48 (Fig. 4) corresponding to each copy size (for example, A4 and B5), and changes the copy cycle according to each copy size. , improving copying efficiency. The above-mentioned differences in cycles depending on the copy size are determined by signals from the force set 6 for each size. Next, the suspension state and restart after copying is completed will be described. If the power supply is left unplugged after all copying operations are completed, the photosensitive drum 15 will constantly rotate, and if the high voltage power supply is left on, this is not desirable in terms of the durability of the photosensitive drum 15 and the blade cleaner 34. . Therefore, in the copying machine of this embodiment, if a certain copying operation is completed and the next copying operation is not performed even after a certain period of time has passed, the drum will automatically stop even if the main switch 10 is 0N. It seems to be going into hibernation mode. This time is set longer than the time required for the transferred transfer paper 7 to be discharged outside the machine and for the entire surface of the photosensitive drum 15 to be cleaned. To perform copying during this hibernation state, use the operating section 9.
When the copy button 13 is pressed, everything returns to the state before the pause, the drum starts rotating, and after 4CP, the document table 2 starts moving forward. This copying machine enters a dormant state 26 CP after the document table reversal command in the final copying process. Next, the specific configuration of the copying machine according to this embodiment will be explained.

In FIG. 3, reference numerals 49 and 50 are front and rear frames, which are strongly constructed by a stay (not shown) and a bottom plate 51 that connect the two frames.

A drum shaft fixing member 52 made of alloy casting is fixed approximately at the center of the rear frame 50, and a drum shaft 53 is fixed to the member 52.
is fixed.

As shown in FIG. 3, the drum shaft fixing member 52 is fixed to the rear frame 50 with a large interval, so that it has sufficient strength against the weight and other forces of the drum 15 even in a substantially cantilevered state. It is composed of

A drum gear 56 is rotatably supported on the drum shaft 53 via bearings 54 and 55. The bearing pusher fitting 57 is fixed to the drum shaft 53 with a screw, and when the drum 15 is removed as described later, the drum gear 56 and the bearing 54
, 55 are held in place so that they do not come off. The other end of the drum shaft 53 (the right end in FIG. 3) is held substantially horizontally by a support plate 58. The support plate 58 is positioned by two positioning pins so that the drum can be removed as described later, and is attached to the frame 4 so that it can be attached and detached using two wing nuts.
It is fixed at 9. The support grip 58 has a thrust holding member 59 movable in the thrust direction, which pushes a bearing 61 held on the drum by a spring 60 to the left in FIG.
The photosensitive drum 15 is designed to have no play in the thrust direction. The photosensitive drum is formed of a front flange 63, a rear flange 64, a guide pipe 65, two rods 66, and bearings 61, 67 that are press-fitted into the front and rear flanges 63, 64. It is assembled by tightening with scissors and rod 66. The guide pipe 65 is for guiding the drum so that it can be easily attached and detached when the drum is attached and detached along the drum shaft 53. The rear flange 64 has a hole that can engage with a drive pin 68 fixed to the drum gear 56, and the two engage to rotate the drum. By supporting the drum quasi-cantilevered as described above, the drum is compactly constructed and easily assembled and disassembled while providing sufficient strength. By fixing the drum shaft 53 to the machine body and configuring it with a hollow pipe, a heating element 69 is installed inside the drum shaft 53 to keep the photoreceptor at a constant temperature, thereby preventing moisture from condensing on the drum surface at times of high humidity. Furthermore, it is possible to obtain high-quality images in a low-temperature environment. The upper end of the rear frame 50 includes a guide rail 70 and control signal magnetic sensing elements 48A, 48B, . The members 73 and 74 to which the 48C71 and 72 are attached are fixed (see Figures 3 and 4).
figure).

Further, guide rollers 75 and 76 as shown in FIG. 3 are installed at the upper end of the front frame 49, and cooperate with the guide rail 70 to cause the document table 2 to move back and forth smoothly. The document table has a front angle 78 and a rear angle J and V connected by a stay, and has a refined frame that has sufficient rigidity to withstand various forces during forward movement, backward movement, and reversal. A transparent glass 5 is placed in the center of the frame, and other pages of the book are placed on the front side of the frame (the left end in Figure 1) when copying a book, etc., so that the entire page to be copied is placed well on the glass surface. The document table 2 is constituted by a case 4 provided for close contact. The rear guardrail 70 is attached to the rear frame 50 by mounting members 73 and 74.
The lower rail 79 and the rear angle of the document table are fixed through the
It is composed of an upper rail 81 fixed to the JMoV and a retainer having a metal ball 80 that is rotatably held between the upper and lower rails and is positioned at the rear angle of the document table. and the position in the front-rear direction (left and right in FIG. 3). Further, the reciprocating movement of the document table is guided by the rolling movement of the metal ball 80. On the other hand, the angle 7 in front of the manuscript table
The protruding rail portion 3 of 8 is sandwiched between a lower guide roller 76 and an upper guide roller 75 to regulate the vertical position of the document table. Guide rollers 75, 76
are rotatably held by shafts 82 and 83, which are fixed to a mounting plate 84 and firmly held by the front frame 49. As described above, the rear guide rail 70 regulates the vertical and front-back (left-right in FIG. 3) position, and the guide roller regulates the front angle of the document platen only in the vertical direction. The reciprocating movement of the table is performed very smoothly regardless of manufacturing errors or assembly errors of the machine. The guide rail mounting bases 73 and 74 are provided with magnetic sensing elements 48A.
, 71, 72, 48B, and 48C are fixed, and control signals are sequentially outputted by magnets 161, 162 attached to the document table 2. When the copy button is pressed and the document table 2 starts moving forward, the magnet 161 and the element 71 first issue a paper feeding command. Furthermore, the document table moves forward and each copy size (
B5, A4, B4) has been exposed and the magnet 161 is attached to the element 4.
When reaching above 8A, 48B or 48C, a reversal command is issued,
The document table 2 moves from forward movement to backward movement. The double movement progresses and magnet 1
When the document plate 62 reaches the element 72, a stop command causes the document table 2 to stop at a predetermined position. The size switching command is issued by force set 6. One drive relationship will be explained with reference to FIGS. 5 and 6. The main motor M1 is driven by a sprocket wheel 85 via a chain 86 and a sprocket wheel 87 to a drum drive shaft 89 to which a gear 88 interlocking with the drum gear 56 is fixed at one end.
The chain 86 further drives a sprocket wheel 90 rotatably mounted on the shaft of an electromagnetic clutch 94.
Drive. A rudder wheel 143 is fixed to the shaft of the electromagnetic clutch on the back side of 94.

(Figure 10) The rudder wheel 143 is the rudder chain 142
is connected to the rudder wheel 141 fixed to the output shaft of the clutch motor 95. A winding drum 91 is attached to the other end of the electromagnetic clutch shaft, and a document table 1 driving wire 92 is wound several times around the drum 91. Both ends of the wire 92 are guided by free guides 93, forming a document table. It is fixed at the tip and rear end of the rear angle JMoV. The electromagnetic clutch 94 and the clutch motor 95 are switched and driven once to rotate the winding drum 91 in the forward and reverse directions, thereby causing the document table 2 to reciprocate. A gear 96 is fixed to the drum 1 drive shaft 89, and the drive of the main motor M1 is transmitted via a gear 97 to a gear 99 fixed to the paper feed roller drive shaft 98. The main motor M is driven by a gear 100 which is integrally fixed with the gear 99, and the gear 101 is driven by the clutch 10.
2 to drive register rollers 41 and 42. Also, gear 100 is interlocked with gear 103, and clutch 1
A paper feed roller control cam 139 is driven via the feed roller control cam 37. The drum gear 56 intertwines with a gear 105 fixed to the separation shaft 104 to drive the separation roller 106. A ladder wheel 107 is fixed to the other end of the separation shaft 104, and discharge rollers 110, 111 are connected via a ladder chain 108 and a ladder wheel 109.
1 drive. 1 through a chain 86 from a sprocket wheel 85 attached to the main motor M1.
The gear 11 is attached to the driven sprocket wheel 112.
3 are integrally fixed, and the gear 113 intertwines with a gear 115 fixed to an arm 114 holding a tarok pulse generating magnet 163 to rotate the magnet, thereby rotating the magnet 115 fixed to the rear frame 50. The detection element 164 and the magnet generate clock pulses at regular intervals synchronized with the rotational speed of the main motor M1. 1 shown in Figure 4
38 indicates the paper feed control section and the copy button 1
3 is pressed and the document table 2 moves forward and reaches a predetermined position, a paper feed signal is output, and the constantly rotating paper feed roller 40 descends to feed out one sheet of transfer paper in the force set 6. Paper feed roller 4
The leading edge of the transfer paper hits the register rollers 41 and 42, which are stopped at the same time as the guides 116 and 11.
A transfer paper loop is created between 7. Then, the paper feed roller 40 rises, the register rollers 41 and 42 rotate again, and
The transfer paper 7 is fed into the machine at a speed that matches the circumferential speed of the photosensitive drum 15. The document table moves forward and backward by the drive system as described above.
In the copying machine of this embodiment, the speed of the backward movement is approximately four times that of the forward movement (approximately 200 m7IL/Sec) in order to improve the copying efficiency, that is, to reduce the loss time during the backward movement.

In order to stop the document table, which moves at such a high speed, at a predetermined position on the machine body without applying a shock, this machine has a lock mechanism as shown in FIG. 12. The locking mechanism basically consists of a combination of a one-way clutch and a brake.
In FIG. 4, the solid line in one position of the lock lever indicates the document table in a stopped state. Rear angle J that makes up document table 2
A pin 155 fixed to the motor V engages with a notch 154 of the lock lever 153. Now, when the document table 2 starts to move forward (rightward in FIG. 4) in response to the document table start command, the lock lever 153 is pushed by the pin 155 and rotates clockwise in FIG. At this time, the one-way clutch 156
Since the brake disc 157 is in the releasing direction, the brake disc 157 remains stopped, and the brake disc 157 and the brake shoe 11
The frictional force caused by 58 and 159 does not act as resistance to the movement of document table 2. When the document table further continues to move forward, the rotary lever 153 stops at the broken line position. When the document table 2 reaches a predetermined position and a reversal command is issued, the document table stops forward movement and starts backward movement, heading toward the stop position at about four times the forward movement speed. The pin 155 engages with the lock lever cutout 154 and the lock lever 153
When the brake disc 15 is rotated counterclockwise from the dashed line position to the solid line position, the brake disc 15
7 rotates counterclockwise. The brake disc 157 is sandwiched between brake shoes 158 and 159 and is pressurized by a spring 160, and this frictional force absorbs the inertia of the document table without giving a large shock to the document table. It can be stopped. With this structure, there is almost no load on the document table when it starts, and sufficient braking can be applied when it stops. A developing device of a copying machine according to an embodiment will be described with reference to FIG. 1 and FIG. 3.

In FIG. 1, the developer 25 stored in the developer tank 26 is supplied between the photosensitive drum 15 and the developing electrode 28 by a pump 27, and the latent image on the photosensitive drum 15 is developed with toner. become Capris are removed from the drum surface after development by a capri removal roller 29 disposed close to the drum surface. The capri removal roller 29 is rotated by a driving source (not shown) at a speed relative to the photosensitive plate surface, and the capri removal roller surface is constantly cleaned by a cleaning member 118. A starrer bar 119 located behind the capri removal roller 29 comes into pressure contact with the photoreceptor and removes the developer from the surface of the photoreceptor plate corresponding to the separation belt, thereby preventing the separation belt from becoming contaminated. As described above, the transfer paper 7 that is sent out from the force set, transfers the image on the photosensitive drum, and is separated from the photosensitive drum is guided to the fixing section where it is dried and fixed by heat from the hot plate. In FIG. 4 and FIG. 8, the cross flow fan 120 is fixed to the rear frame 50.
The first suction port 121 of C.
This air flow assists the separation by the separation belt 32 and also improves the adhesion of the transfer paper to the hot plate. Further, the second suction port 125 is not engaged with the conveying section and performs suction from the outside. cross flow fan 12
The air outlet 126 located above the hot plate 124 is guided onto the hot plate through a blow duct 128 fixed to the upper cover 127, and contributes to the feeding and drying of the transfer paper.

As mentioned above, by performing suction and spraying with a single 7-amp, it is effective in downsizing the device and reducing costs, and by forming a semi-circulating system, the surface of the transfer paper is not covered with saturated steam. Drying is also good. Next, we will discuss the operation when paper feeding is defective.

In the copying machine of this embodiment, the transfer paper is processed through predetermined processes (paper feeding, transfer,
The printer is equipped with a jam detection means to check whether the transfer paper has finished separating and fixing and has been ejected outside the machine outside of the predetermined time. The system is designed to stop the machine if it is not discharged, so as to prevent accidents such as fire. In FIG. 1, 129 is a light emitting element, and 130 is a light receiving element.The presence or absence of a jam is determined by counting a predetermined pulse by the clock pulse generation mechanism from the document table reversal command and detecting the presence or absence of transfer paper. However, the details will be explained later. When a jam is detected, the fuser heater is turned off, the main motor M is stopped, the drum 15 is stopped, and the document table 2 is stopped after returning to a predetermined position (home position). When the machine is stopped, the upper cover 127, which can be opened about the hinge 131 in FIG. 1, is opened substantially vertically together with the duct 128.
In this state, nothing remains on the hot plate 124, and if a jam occurs in the fixing section, the transfer paper can be easily removed by hand by opening the upper cover 127. Next, the main body 122 of the transfer paper transport section including the hot plate 124 is rotatably supported by a shaft 132 together with the separation section including the separation belt 32 and the like.
Normally, it is held in place by a locking mechanism 133, and by removing the locking mechanism after opening the upper cover 127, it rotates counterclockwise around a shaft 132, and transfers the data after the register curlers 41 and 42. The paper path is opened and jammed transfer paper can be easily removed by hand. At this time, the separation belt 32 is separated from the photosensitive drum feeder 15, and it is easy to take out the transfer paper jammed in the separation section. After removing the jammed transfer paper, the jam release operation is performed and the upper cover 127 is closed, thereby restoring the entire machine to its original state.

Even if an attempt is made to close the upper cover 127 without performing the jam release operation, the upper cover will not close, the door switch 134 (FIGS. 6 and 7) will not work, and the machine will not be in operation. Further safety is ensured by performing the confirmation operation as described above. Next, a method of attaching the force set 56 to the main body 1 will be described. Place the foot part 145 of the force set 6 on the force set stand 144 fixed to the aircraft body,
When the force set is pushed into the inside of the machine, the force set 6 is moved by the spring 149 which moves the roller 1484 to the right so that the protrusion 146 at the bottom of the force set hits the positioning plate 147 of the force set holder.
is pressed into place. At this time, a cam 150 provided on the force set side wall and micro switches 151, 152 provided on the force set mount 144 output a force set installation signal and a size switching signal. The document holding cover provided on the document table is fixed to the document table with screws 135 and 136, and can be easily removed when it is desired to copy a large three-dimensional object. The paper ejection tray 47 is located behind the paper ejection rollers 46 and 45 (slightly upward as shown in FIG. 2). The tray portion 47b is rotated to an approximately vertical position and fixed. With the above configuration, the force set 6 can be easily attached and detached without removing the entire paper discharge tray 47 from the machine body. As shown in FIG. 3, since the guide rail 70 is installed in a horizontal position, dust and foreign matter are not accumulated on the runner portion 70a, and the movement of the document table 2 is always smooth.

Also, when the document table 2 is in a predetermined position, the guide rail 70
are all located under the document table 2, which is effective from the standpoint of safety and protection. Next, a sequence control circuit using a digital IC will be explained first.

(Reset circuit) The circuit shown in Fig. 14-a is a signal (hereinafter referred to as STOP) that commands to stop the copying operation of the copying machine when the transfer paper is jammed or a spark discharge occurs in the charger, and to reset the entire circuit when the power is turned on. 14th-
Figure b is the time chart.

In FIG. 14-a, an inverted signal "M" of a signal (hereinafter referred to as JAM) output from a transfer paper jam detection circuit, which will be described later, when a jam occurs is input from the terminal 201 to one input terminal of the three-input AND gate 207. Added. However, here, for example, the signal ゞXYZ〃 is a signal at a level that is considered to be a high level signal or logic ~ 1〃 if the event it means occurs, and a level that is considered to be a low level signal or logic XO〃 if it does not occur. Below, each level is simply written as 1 and 0. Further, the signal has a level completely opposite to that of the inverted signal, and is expressed as XYZ. Further, the circuit 202 is a circuit that outputs 1 when a spark discharge occurs in the charger.Detailed explanation is omitted here, but the signal will be hereinafter referred to as DISCH.This DISCH is input from the terminal 203 and is connected to the inverter 20.
4 to the other input terminal of gate 207.
Further, the circuit 205 is a circuit that generates a signal for resetting the necessary parts of other digital circuits to the initial state before starting when the power is turned on. A circuit that outputs 1 after a certain period of time TR is usually an extremely short period of time, and the time interval does not require high precision.It is a circuit that can be easily designed by the engineer concerned, so the details will be omitted. . WU this output below
Represented as P. This WUP is input from terminal 206 and applied to another input terminal of gate 207. Therefore, the first
As shown in Figure 4-b, the input signals from terminals 201, 203, and 206 are 20V, 203'', and 206'', respectively.
The output of the inverter 204, that is, the output of the gate 207 with the inverted signal of 203/ as 204' is 208.
'', it becomes 0 when any one or more of 202', 204', 206' is 0, that is, if JAM becomes 1, DISCH becomes 1, or WUP becomes 0, 0 and is output from the terminal 208 as STOP, causing other necessary circuits to be reset.In addition, the reason for outputting the inverted signal of STOP as the reset signal is to reset the signal in the following circuit. Since it is most convenient to set it to 0 when setting STO
This is to be output as P. (Pre-rotation circuit) Next, a signal to perform pre-rotation when the power is turned on (hereinafter NTR
Figure 15-a shows a circuit for generating .

First, the D-type edge-triggered flip-flop 214 will be explained. When a rising pulse waveform that changes from 0 to 1 is applied to the CP input terminal, this flip-flop changes from the output terminal Q to the input terminal D. The same signal as the digital signal being applied at that time is output,
The output state is maintained until a rising signal is applied to the CP terminal again, but when 0 is applied to the input terminal S or 0 to the input terminal R, the CP. Regardless of the state of each input terminal of D, the Q output becomes and remains 1 and 0 in each case. Also, the output terminal Q is
This is a terminal that outputs an inverted signal of the Q output. Hereinafter, a flip-flop having this function will be referred to as FF. In FF2l4, first, power supply voltage Vcc2l3 is applied to the D terminal. Vcc is a level that is regarded as 1 as a digital signal in the circuit. Further, STOP is applied to the R terminal from the terminal 208. Therefore, since 0 is first added to the R terminal for the time TR from the time the power is turned on, 1 is output from the terminal Q and this state is maintained, but the details will be described later. A signal 16CP from the clock pulse counter circuit indicating that the drum has rotated approximately once is sent to terminal 211.
is applied to the CP terminal, and when this 16CP rises, the Q terminal becomes 0. The output of this Q terminal is further N
In addition to one input terminal of AND gate 215, STOP is applied to the other input terminal. Therefore, the output of the gate 215 is as shown in the time chart No. 15-b in Fig. 21.
As shown in 6', the output 214'' of the Q terminal becomes 0, which is obtained by subtracting the period TR from the time the power is turned on, from the period 1, and the output I indicates that the pre-rotation is to be performed for this period.
It is output from the terminal 216 as an inverted signal 1NTR of NTR. Here, outputting the inverted signal is convenient for subsequent circuits. In addition, in Figure 15-b, 2
1V and 208'' indicate signals input from terminals 211 and 208, respectively. (Counting means) Next, the clock pulse counter circuit will be explained with reference to FIG. 16a and its time chart in FIGS. 16-B and 16-c.

First, the circuit 221 is a clock pulse generator, which detects periodic changes in magnetic field strength using a magnetosensitive element, generates a pulse according to the output of the element, and uses it as a clock pulse. 161) is periodically passed near the magnetic sensing element 71 in FIG. This generates a panel-shaped output as the output. The circuit 231 is a known binary counter, and is triggered when a falling signal from 1 to 0 is applied as a clock pulse to the CP input terminal, and the output terminal A outputs the clock divided into 1/2. , an output whose frequency is divided to 1/4 is generated at the output terminal B, an output whose frequency is divided to 1/8 at the output terminal C, and an output whose frequency is divided to 1/16 to the output terminal D. That is, these outputs are 231'A and 23V in Figure 16-b, respectively.
B, 23 "C, 23l" as shown in D. However, the first
6-b, 22γ is a signal input from the output terminal 222 of the clock pulse generator 221 in FIG.
The clock pulse signal at the terminal 222 will be referred to as CLCK below.
When 1 is added to the CLEAR input terminal of A, B, C
, D are all 0, and the state at this time is as shown in Figure 16-b.
The result is exactly the same as when adding the th. Also, CLEAR
Unless 1 is added to the terminal, the output state is 1 from the Oth
Repeat the fifth state and use CLEAR in the following explanation.
When 1 is applied to the terminal, the times when clock pulses corresponding to the 0th and 16th clock pulses are applied are all referred to as the state in which the 16th clock is applied.

In FIG. 16-a, the following three types of reset signals are applied to the CLEAR terminal of the counter 231 in order to effectively operate other circuits. First, when the power is turned on, STOP is input from terminal 208 as a reset signal to input N.
is applied to one input terminal of AND gate 225, and also indicates that the document table (FIG. 1, 2) has reached the reversal position. An inverted signal CBBP of signal CBBP (details will be described later) is applied from terminal 223 to another input terminal of gate 225. A pulse signal indicating the end of post-rotation is applied to the other input terminal of the gate 225, and this can be created as follows. First, signal L indicating that the rear rotation is in progress.
The inverted signal LRT of RT (details will be described later) is connected to the terminal 224.
is first directly applied to one input terminal of the two-man power AND gate 242, and then applied to the inverters 227, 228, 22.
9 to the other input terminals. At this time, the 16th
Signal 224'' at terminal 224, as shown in figure -c.
and the output 229'' of the inverter 229 are inverted, but since the signal 229'' passes through three inverters, there is a delay in the signal compared to the signal 224''. Let this delay time be TD. , output signal of gate 242, 2
42' is at the falling edge of LRT as shown in the figure, that is, when the signal 22
T from the rising edge of signal 4' to the falling edge of signal 229'
It becomes time 1 of D. After this, a signal indicating the end of rotation (hereinafter L
(written as RTEP) is output from a terminal 243 to other circuits and is further applied to a gate 225 via an inverter 226. Therefore, it becomes a reset signal. gate 22
The output signal 225'' of 5 is STOP,
When either CBBP or LRTEP becomes 1, the counter 231, which is output as 1, is reset (cleared). Next, the outputs of the counter 231 are further combined as follows. First, to the two-man power AND gate 235, the D terminal inverted output via the inverter 234 of the C terminal output and the D terminal output is applied to each input terminal, and to the two-man power AND gate 236, the output of the gate 235 and the B The terminal output is added to each input terminal, and to the three-input AND gate 237, the C terminal inverted output via the inverter 233 of the B terminal output and the C terminal output, and the D terminal output are added to each input terminal. The input AND gate 238 has terminal outputs of B, C, and D connected to inverters 232, 233, and 23, respectively.
An inverted output via 4 is applied to each input terminal. Therefore, the outputs of the respective AND gates are as shown in FIG. The period of the clock pulse is 1, and the output 241'' of the gate 237 is 1 from the 10th clock pulse.
Period 1 of the first clock pulse, and gate 2
The output 21 of 38 is the period 1 of the 16th (Oth) to the 1st clock pulse, and the outputs 21 of 38 are the period 1 of the 16th (Oth) to
From 240, 241, 211, 4CP, 6CP, 10
It is output as a CP, 16CP signal. In addition, the clock pulse mentioned above is 15 per drum rotation in this embodiment.
．． 75 occur. This means that in the 16-bit counting method described above, when 16 clock pulses are counted, it can be effectively determined that the drum has made almost one revolution. Next, the copy size signal generation circuit will be explained with reference to FIG.

In this embodiment, in order to improve the time efficiency of the copying process, an endless photosensitive drum is used as described above, and control is performed according to each copy size. Each copy size is automatically determined at the same time as the transfer paper force set is inserted into the main body. Specifically, the circuit shown in Fig.
Four types of status are discriminated: size cassette and B5 size cassette. In Figure 17, micro switch 2
46 and 247 are both in the open state (when no force set is inserted), and at this time, the output parts 246' and 247'' are connected to the power supply voltage Vcc through the resistors 248 and 249, respectively, so the signal state is 1. However, when the microswitches 246 and 247 are switched to 0N by inserting the force set, the output sections 2465 and 247'' are connected to the zero potential section GND (earth) and become in the signal state of 0. In this embodiment, when a B4 size cassette is inserted, the micro switch 247 is switched to the ON state, and when an A4 size cassette is inserted, the micro switch 246 is switched to the ON state, and then the B5 size cassette is switched to the ON state. When inserted, the micro switch 246,
Both the 247 and 247 are switched to the 0N state. Here, to the two-man power AND gate 252, the signals at the output parts 246'' and 247" of the microswitch are applied to each input terminal, and to the two-man power AND gate 253, the signals at the output part 247" are applied to the two-man power AND gate 253.
' and the inverter 251 at the output 246''
The signal via is added to each input terminal and
The signal at the output section 246'' and the signal via the inverter 250 at the output section 247'' are applied to the gate 254, and the two-man AND gate 255 receives the signal at the output section 246''.
, 247'' through inverters 250 and 251, respectively. Therefore, the output of gate 252 becomes 1 when no force set is inserted, and is output from terminal 256 as a signal without force set (hereinafter referred to as CEP). Furthermore, the output of the gate 253 becomes 1 when a B4 size cassette is inserted, and is output from the terminal 257 as a B4 size copy signal (hereinafter referred to as B4C).
The output of gate 4 and the output of gate 255 are an A4 size copy signal (hereinafter referred to as A4C) and a B5 size copy signal (
(hereinafter referred to as B5C) is output from terminals 258 and 259. Next, a copy execution command signal (hereinafter referred to as CCMD) generation circuit is shown in FIG.

First, the circuit 261 uses a magnetic Hall element in the same way as the circuit 221 in FIG. This circuit performs electromagnetic conversion using the output of a Hall element that detects changes in the magnetic field strength using the Hall effect, and generates an output of 1 when the copy button is pressed. This output is used as a CCP. , is input from terminal 264 and applied to one input terminal of four-power AND gate 270. Further, the circuit 262 is connected to a developing device (
In this embodiment, the circuit 261 is a circuit that outputs 1 as LEP when the developer becomes low in FIG. 124).
Similarly, a pair of magnet and Hall element is used.
This output LEP is applied from terminal 265 via inverter 267 to another input terminal of gate 270. The circuit 263 is a circuit that outputs 1 as PEP when there is no more paper in the force set. This circuit detects the presence or absence of paper by utilizing the fact that when the paper runs out, the light emitted from the lamp is strongly irradiated on the CdS, and this output becomes 1 as a PEP signal when the paper runs out. Next terminal 2
66 through an inverter 268 to another input terminal of gate 270. Furthermore, CEP generated from the circuit of FIG. 17 and output from terminal 56 is applied to another input terminal of gate 270 via inverter 269. Therefore, the output of the gate 270 is that when the copy button is pressed, COP becomes 1, and when the current liquid is filled, LEP becomes 0, and when there is transfer paper during force setting, PEP becomes 0, and further force setting is performed. CEP itself is installed
becomes 1 when CCM is 0, and CCM is output from terminal 271.
It is output as D. Next, FIG. 19 shows a circuit that generates a signal CEXC (hereinafter simply referred to as CEXC) indicating that a copy operation is in progress.

The signal CEXC starts from the time when the copying machine starts moving forward to copy the first page after the copier is turned on.
As will be explained in detail later, this is the signal for period 1 when the last copy is completed and the subsequent post-rotation is completed.
6, the original table advance command signal CBFOR is sent to the inverter 2.
82 to the S terminal of the FF 28l. Therefore, as will be described later, when the first manuscript table advance command signal CBFOR becomes 1, the output Q of the FF 28l, which is preset by the STOP 0 signal when the power is turned on, becomes 1, and the terminal 28
3 is output as CEXC. Furthermore, since the STOP signal including the reset signal when the power is turned on is applied from the terminal 208 to one input terminal of the two-man AND gate 280, when STOP becomes 0, the output of the gate 280 also becomes 0, and this output is further applied to the FF 28l. Since it is applied to the R terminal of , the output Q becomes 0. Further, the FF28l Noriset is further inputted from the terminal 243. LRTEP signal is 1
It is also done by becoming. LRTEP is the 16th a
, as explained in FIG. 16-c, is a signal that becomes 1 only during the time TD at the end of the post-rotation, and the two-man power N is output from the terminal 208.
It is applied to one input terminal of AND gate 279. Also, since the CCMD signal is applied from the terminal 271 to the other input terminal of the gate 279 via the inverter 278, LRTEP is inverted only when CCMD is 0 and is applied to the gate 280, but this is not possible during post-rotation. This is to prevent CEXC from being reset even if the copy button is pressed and CCMD becomes 1 and LRT falls at this time as will be described later.

Next, FIG. 20 shows a pre-exposure strong illuminance lighting command signal BRIGHT (hereinafter simply referred to as BRIGHT) generation circuit.

As described above, in order to improve the efficiency of the copying process in this embodiment, the following photosensitive drum (hereinafter simply referred to as drum) rotation sequence is set up. After the power is turned on and each circuit is reset by the WUP signal, this copying machine first performs one rotation of the drum as a pre-rotation, and if the copy button is not pressed at this time, the drum stops rotating and is in a rest state. to go into. In this dormant state, the copy button is pressed and the CCM
When D becomes 1, the cleaning blade (Fig. 1, 34) marks that may be formed on the drum when the drum is stopped is avoided when copying the first sheet, and the 4-clock clock is used to wait for the delay in lighting time of the fluorescent lamp. After waiting, the advance of the document table is started, and when the latent image is formed for this first copy, the drum is exposed to light immediately before the primary charger (Fig. 1, 21), and the drum photosensitive layer is exposed during continuous copying. Difference in condition. is being corrected. However, this exposure (hereinafter referred to as pre-exposure) remains dark even when copying the second and subsequent sheets, but the circuit shown in Figure 20 generates a BRIGHT signal as a signal to turn on the pre-exposure strongly when copying the first sheet. This is a circuit that allows First, C
The state where CMD is 1 and CEXC is 0 appears only immediately before the first copy is executed, as described in the CEXC generation circuit (FIG. 119). The CCMD signal is applied from terminal 271 to one input terminal of two-person NAND gate 293, and the CEXC signal is applied from terminal 283 through inverter 289 to the other input terminal of gate 293. Therefore, when CEXC is 0 and CCMD is 1, the output of gate 293 is 0, which is added to the S terminal of FF 295, and the output Q of FF 295 becomes 1, which is applied to terminal 2.
98 is output as a BRIGHT signal. BRIG
The pre-exposure illuminance, which has become strong when the HT signal becomes 1, must be returned to weak illumination after the drum has rotated approximately once in order to achieve the above-mentioned purpose. Therefore, in the case of A4 size copy and B4 size copy, when the signal A4BP (details will be described later), which indicates that the document table has come to the A4 size inversion position, becomes 1, and in the case of B5 size copy,
Since the document table does not reach the A4 size inversion position, the document table reaches the B5 size inversion position, the counter 231 in FIG. 16-a is reset as described above, and then the fourth clock pulse is input. Therefore, when the rising 4CP signal is issued, the FF 295 is reset, thereby stopping the pre-exposure high illuminance and irradiation. In the circuit, first, the A4BP signal is sent from the terminal 287 to the FF 29 via the inverter 291 and the three-input AND gate 297.
5 is added to the R terminal. Therefore, when A4BP becomes 1, 0 is added to the R terminal, FF 295 is reset, and the output Q becomes 0. Further, since A4BP does not become 1 and the signal where the 4CP signal rises is applied from the terminal 288 to the CP terminal of the FF 295, and the D terminal is connected to GND (earth), the output Q of the FF 295 becomes 0. Here, as a signal to further reset the FF295, STOP
CEC from l and terminal 283 via inverter 289
EXC is inverted and applied to one input terminal of two-power NAND gate 294, and terminal 271 is applied to the other input terminal.
CCMD is applied from the inverter 292 through the inverter 292.
The outputs of the gates 294 are applied to the R terminal of the FF 295 via gates 297, respectively. This is because STOP, which is a reset signal when the power is turned on, resets the FF295, and CCMD becomes 1 and CE
If XC is 0 and after setting FF295 (output Q is 1), even if 4CP rises and CBFOR rises, CCMD becomes 0 before CEXC rises. Since the table does not move and no copying is performed, at this time, CEXC becomes 0, CCMD becomes 0, and the output of gate 294 is set so that the pre-exposure is returned to a weak illuminance.

Here, the 4CP signal is FF29 during B5 size copying.
5 is reset, so it is added to the CP terminal, but the CC
Even if the 4CP signal rises after MD becomes 1, as will be described later, {ζ Original table advance command signal CBFOR becomes 1 when 4CP rises and CEXC when CBFOR rises.
CEXC remains 0 immediately after 4CP rises, and at this time, due to the rise of 4CP, FF295
The beam is not set. Next, the post-rotation command signal LRT generating circuit is shown in FIG. 21-a, and its time chart is shown in FIG. 21-b, and will be explained. In this embodiment, the post-rotation is performed after the latent image formed on the photosensitive drum and left in the gap in the last copying process is transferred to the transfer paper, and ends after the drum has rotated approximately one revolution. First, FF3O5 is reset by the STOP signal applied from the terminal 208 to the R terminal via the two-man AND gate 304 when the power is turned on, and the Q output and the Q output become 0 and 1, respectively. Next, the 10CP signal is applied from the terminal 241 to the CP terminal of FF3O5,
This signal becomes 1 during the forward rotation, while the document table is moving forward, and at the time when transfer ends after the document table reaches the reversal position and the counter 231 in Figure 16-a is reset. do. Therefore, first, the D terminal of FF3O5 is connected to the terminal 2.
CEXC from 83 is applied to one input terminal of the three-input AND gate 303, the inverted signal of CBFOR is applied from the terminal 276 to the other input terminal via the inverter 301, and the output Q of FF3O5 is applied to the other input terminal. By adding the output of the gate 303 to FF3
When O5 is set, the Q output becomes 1 because CEXC is 1.
And only when CBFOR is 0 and LRT is 0,
Occurs at the end of transcription. By 10CP, F
A state is reached in which F3O5 can be set.

However, since CCMD is inverted and applied from the terminal 271 to the R terminal of FF3O5 via the gate 304, FF3O5 is actually set when CCMD runs out and becomes 0, that is, when the last one This happens when copying. This further means that if the copy button is pressed and CCMD becomes 1 while FF3O5 is set and LRT is 1 and post-rotation is being executed, post-rotation will be stopped at that point. Also, 10CP signal is 1
After rising, 10CP rises again when 16 clock pulses occur, as described in the explanation of FIG. 16-a. Therefore, during this period, the drum rotates approximately one revolution, and at this time, the output Q of FF3O5 applied to the gate 303 is O, and the D terminal is 0, so the output Q of FF3O5 is 0. is set and post-rotation is completed. Note that the output QlQ of FF3O5 is outputted from terminals 306 and 224 to other circuits as LRTlLRT, respectively. A time chart is shown in Fig. 21-b. Signal 208″, 27″, 276″, 283″, 24
", 306" are terminals 208, 271, 276, respectively.
In the signal waveforms at 283, 241, and 306, after two consecutive copies, the 10CP signal rises and LRT rises, but after this, one copy is performed again after rotation. It is. Next, a circuit for generating a command signal for advancing and retracting the document table is shown in FIG. 22 and will be described.

First, to explain the document table moving sequence, after the power is turned on, forward rotation is performed, but when CCMD becomes 1 after the end of the forward rotation (although CEXC is still 0 at this time), the document table waits for 4 clock pulses. When it starts moving forward from , and reaches each reversal position of B5, A4, and B4, it starts moving backward and returns to the document table home position (starting position). However, in this embodiment, if the document table is not at the home position, the document table cannot be started, but when the power is turned on, the document table automatically moves to the home position. In this embodiment, the position detecting device for these document tables is the 16th-
Similar to the clock pulse generator shown in Figure A, this is done using a pair of magnet and Hall element.

That is, a magnet is attached to the document table, and a Hall element fixed to the main body detects changes in the magnetic field strength due to the movement of the magnet, so that the document table returns to the home position.
A signal indicating that the reversal position has been reached for each copy size of B5, A4, and B4 is generated. In the circuit shown in FIG. 22, a signal CBHP (hereinafter referred to as CBHP) indicating that the document table is at the home position is applied from a terminal 311 to one input terminal of a two-man power AND gate 315, and a signal CCMD is applied from a terminal 271 to the other input terminal. Applied to human power terminals.

Therefore, if CCMD becomes 1 when the document table is at the home position, the output of gate 315 becomes 1, and FF 324
is added to the D terminal of Also, two-person NA from terminal 222
Since the CLCK signal is applied to one input terminal of the ND gate 316 and the CEXC from the terminal 283 is applied to the other input terminal, when CEXC is 1, the gate 316 outputs an inverted signal of CLCK. Also two-person NA
The 4CP signal from the terminal 288 is applied to one input terminal of the ND gate 319, and CEXC is applied to the other input terminal via the inverter 318, so when CEXC is 0, an inverted signal of 4CP is output from the gate 319. Ru.
The outputs of these gates 316 and 319 are further connected to three inputs NAN
It is applied to the input terminal of the D gate 317, and the Q output of the FF 324 is further applied to the input terminal of the gate 317. Therefore, when the Q output of FF324 is 1, C
The LCK or 4CP signals are sent to the gates 316 and 316, respectively.
319 and added to the CP terminal of the FF 324. Therefore, when copying the first sheet, that is, when CCMD becomes 1 when CEXC is 0, the FF 324 is set and the output Q becomes 1 at the rising edge of the 4CP signal, and the terminal 27
6 to document platen advance command CBFOR (hereinafter simply CBFOR)
) is output.

In addition, for the second and subsequent copies, CEX has already been used at this time.
Since C is 1, when the document table returns to the home position and CBHP becomes 1, the next input CLCK
When the signal rises, CBFOR becomes 1 and the document table moves forward. Next, for reversing the document table, the output of the three-input AND gate 322 is transferred to the FF 32 through the two-man AND gate 323.
This is done by adding it to the R terminal of 4. That is,
For B5 size copy, the B5C signal is set to 1 and terminal 2
59 is applied to one input terminal of the two-power NAND gate 320, and B5BP is applied from terminal 312 to the other input terminal. Therefore, when B5BP becomes 1 at this time, it is inverted through gates 320, 322, and 323 and becomes FF.
324 and resets the FF324.
In the case of A4 size copy, terminals 258 and 28 are used in exactly the same way.
The A4C and A4BP signals respectively input from 7 are applied to each input terminal of a two-man power NAND gate 321, and the output is further applied to one input terminal of a gate 322. In the case of B4 size, B4BP is inverted from the terminal 313 via the inverter 327 and applied to another input terminal of the gate 322. Therefore, each document table inversion signal is inverted via gates 322 and 323 and sent to FF 32.
is added to the R terminal of 4, and at this time the output Q becomes 1,
A terminal 32 receives a document table backward movement command signal CBREV (hereinafter simply referred to as CBRE) through a two-man power AND gate 325.
6 to other circuits. However, when the document table returns to the home position at the gate 325 and CBHP becomes 1, 0 is applied to one input terminal via the inverter 314, so CBRE becomes 0 and backward movement is stopped. Note that STOP is also applied from the terminal 208 to the R terminal of the FF 324 via the gate 323 in the same way as other circuits.

Further, the output of the gate 322 is an inverted signal of the document table reversal position signal, and is outputted as CBBP from the terminal 223 to other circuits. Figure 22-b shows a time chart of 31V, 222'', 322', 276'', 3 in the circuit shown in Figure 22-a when CCMD and CEXC are 1.
The signal waveforms shown at 26″ are CBHP, CLCK, and
These are the symbols CBBP, CBFOR, and CBRE. Next, FIG. 23 shows a paper feed start command signal PFSD (hereinafter simply referred to as PFSD) generation circuit.

In the figure, from the terminal 331, a signal indicating that the document table has reached a specific position is generated using a means completely similar to the document table reversal position detection means shown in FIG. 22-a, and this is the paper feed timing signal PFSP. As input, two-man power A
It is applied to one input terminal of ND gate 332. Other input terminals of gate 332 include CBFO from terminal 276.
Since R is added, the PFSP becomes 1 while the document table is moving forward.
When input as PFSD, the output of gate 332 becomes 1, and is output from terminal 336 as PFSD. Further, in this embodiment, the PFSD signal and each copy size signal are added to each input terminal of a two-man AND circuit, and the output thereof is used as a count signal for the number of copies. That is, in FIG. 23, B5C, A4C, and B4C are terminals 259 and 258, respectively.
, 257 and input AND gates 333, 33
In addition to one input terminal of 4,335, the output of each gate is connected from terminals 337, 338, and 339 to B5COUNT, respectively.
Output as T, A4COUNT, B4COUNT. Next, Figures 24-A, b, and c are circuit diagrams and time charts for detecting the occurrence of phenomena such as abnormal conveyance of transfer paper in the copying process, that is, extreme delays, and phenomena such as jamming in the conveyance path (hereinafter simply referred to as jams). Show and explain.

First, in Figure 24-a, from the terminal 223 to the 22-
The CBBP signal whose generation process is explained in figure a is input and F
It is applied as a set signal to the SD terminal of F344. Therefore, when CBBP becomes 0, the output Q of the FF 344 becomes 1, and this signal is further applied to one input terminal of the two-man NAND gate 345. Also, the other input terminal of the gate 345 receives the jam timing signal JTP from the terminal 342.
(hereinafter simply referred to as JTP) is added. This JTP determines how long it takes to reach a specific position in a predetermined path through the normal conveyance process when the leading edge of the transfer paper reaches a specific position in a predetermined path after the transfer process and the drying/fixing process are completed. A pulse signal that is generated after a period of time including a minute margin.
When JIP becomes 1 when the output Q of FF 344 is 1, the output of gate 345 becomes 0, which is applied to the SD terminal of FF 346 to set FF 346. That is, the output Q of the FF 346 becomes 1, and the jam generation signal JAM is sent to the terminal 34.
Output from 3. Note that the JAM inversion signal JAM is FF3
The Q output of 46, that is, is output from the terminal 201 to other circuits. Here, if the transfer paper is conveyed normally, a signal PDP (hereinafter simply P
(written as DP) is applied from the terminal 341 to the CP terminal of the FF 344, and the D terminal is connected to GND (earth) and set to 0, so when the PDP signal rises from 0 to 1, the output Q of the FF 344 changes. becomes 0, and even if JTP becomes 1 at gate 345, the output does not become 0 and FF34
6 is not set. In the time chart of FIG. 24-c, part A shows the signal waveforms during normal conveyance, and part B shows the signal waveforms when a jam occurs. However, the signal waveform 223″, 3
4", 342', 344", 343" are CBB respectively
P, PDP, JTP, Q output of FF344, FF346
These are the signal waveforms of the Q output (JAM) of . Furthermore, signal 34V
The broken line in indicates the case where the transfer paper did not reach the specific position or the arrival was extremely delayed. In this embodiment, the paper detecting means at the specific position is as shown in FIG.
Similar to the paper detection device described in the EP signal generation circuit, this device uses a lamp and a pair of CdS photosensitive elements. Next, regarding the JTP generation circuit described above, the circuit shown in FIG. 24-b was used in this embodiment. In this embodiment, as shown in FIG. 16-a, the clock pulse counter 2
31 The document table is reset to the reverse position, and then,
The number of times the leading edge of the transfer paper reaches the specific position due to normal conveyance is 1 for each size of B5, A4, and B4.
This is about one second before the 0CP, 6CP, and 4CP signals are generated, and therefore, each signal is used as a jam timing signal. That is, as shown in FIG. 24-b, the A4C signal from terminal 258 is applied to one input terminal of two-power NAND gate 348, and the 6CP signal from terminal 240 is applied to the other input terminal. Therefore, the output of the gate 348 is an inverted 6CP signal and is applied to one input terminal of the three-input N/D gate 350 only in the case of A4 size copying. Also, in the case of B4 size copy, B4C and 4CP are input from terminals 257 and 239, respectively, and two-person NAND
The output of gate 349 is applied to the input terminal of gate 349 and is applied to another input terminal of gate 350.
Further, the 10CP signal is inverted via an inverter 347 and applied to another input terminal of the gate 350.
Therefore, in the case of B4 size copy, 4CP and 10CP signals appear in the output of gate 350, and in the case of A4 size copy, 6CP and 10CP signals appear, and in the case of B5 size copy, only the 10CP signal appears, terminal 342
is output as a JTP signal. Note that, apart from this embodiment, the JTP signal may also be generated, regardless of the copy size, for example, after a certain period of time has elapsed from the time when the document table starts moving forward or from the time when the paper feed start timing pulse is generated. Next, the aforementioned control signals are appropriately combined to control the energization switching elements in order to energize each terminal element according to the process conditions of the copying process. When a pulse transformer is used as the triax ignition circuit, an output circuit, an example of which is shown in FIG. 25, is used.

Figure 25 shows an example of a signal generation circuit that controls the energization of the main motor (M in Figure 5).
Terminals 271 and 283 are used to drive the main motor when any one of EXC and INTR becomes 1.
, 216, CCMD, CEXC,
The INTR signals are added to each input terminal of the three-input 0R gate 408 and combined, and the output of the gate 408 is further combined with the two-input A
It is applied to one input terminal of ND gate 409. In addition, by adding the output signal 0SC from the astable multivibrator circuit 402 to the other input terminal of the gate 409, the output of the gate 409 will produce an output from the circuit 402 only when the output of the gate 408 is 1, and from the terminal 4611 to the main Switches energization to the motor. It is amplified and added to the pulse transformer in the triac's ignition circuit.
The digital circuit that is the core of the control circuit has been described above, including sequence control. Next, FIG. 26 shows a circuit that switches the current supplied to each terminal element in accordance with the output of the control circuit.

In the figure, P is an AC input power supply, RLl, RL2, RL3
are each terminal element, and Gl, G2, and G3 are tri-amps for switching the current to each terminal element. Tl, T2,
T3 is a trigger pulse generated from a normal triac trigger generation circuit (not shown) in accordance with a signal from the control circuit (for example, FIG. 25). Further, S, , S2 are main switches with two interlocking circuits. Therefore, RL1 has the main switch 0N.
, 0FF, the current can be energized by the generation of the trigger signal T1 until the completion of a predetermined sequence.
In this circuit example, RLl includes a main motor, high voltage AC output, etc. Furthermore, when main switches Sl and S2 are turned ON, RL2 applies a trigger voltage to G2 via S2 and resistor R2, making G2 conductive and can be energized.Furthermore, even if the main switch is turned OFF, It continues to be energized as long as the trigger signal T2 from the control circuit is generated, and in this circuit example corresponds to a power transformer for maintaining the control function. Further, RL3 stops energizing when the main switch is turned OFF even if the trigger signal T3 from the control circuit is generated, and in this circuit example, it includes a fuser heater and the like. Here, including a power transformer of a power supply circuit for applying power supply voltage to the control circuit in RL2 means that the control circuit is connected to the main switch S.
This is necessary in order to keep the control circuit in an operable state even when l and S2 become 0FF. It should be noted that the power supply circuit and the trigger pulse generating circuit may be ordinary ones, and other associated circuits not directly related to the present invention may be ordinary ones, and have been omitted for the sake of simplifying the explanation. Also, No. 26-a
In the figure, if it is necessary to cut both sides of the input power supply of each terminal element included in RL3, the connection at point t may be changed from point u to point s, and the current-carrying circuit of RL2 is connected to the second
As shown in Figure 6-b, one line L from the AC input power supply P
Connect one terminal of each of Sl and S2 to 1, and connect S1 to RL3.
, G3, and the trigger voltage is supplied from S2 to G2 via R2, the above effect can be obtained. Although the case has been described here in which the switches S3 and S4, which directly turn on and off the power, are in the on state, it is convenient to use the switches S3 and S4 as door switches for the case of the copying machine. In other words, when performing jam removal after detecting a jam, when the door is opened, this switch is shut off and the voltage applied to switching elements Gl, G2, and G3 is turned off, so conduction to all loads and control circuits is turned off, and even more Safety can be ensured.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the copying device, Fig. 2 is a perspective view of its external appearance, Fig. 3 is a longitudinal sectional side view of Fig. 1, and Figs. 4 and 5 are sectional views showing the driving relationship of the copying device. and a perspective view, FIGS. 6 and 7 are partial sectional views showing the operation of the safety device, FIG. 8 is a perspective view showing the fixing device, FIG. 9 is a sectional view showing the sheet feeding device drive section, and FIG. 10. 11 is a perspective view showing the force setting, FIGS. 12 and 13 are sectional views showing the document table stopping device, and FIG. 14-a shows the beam set command signal generation circuit. Figure 14-b is the time chart, 15th
Figure 15-a is the pre-rotation signal generation circuit, Figure 15-b is its time chart, Figure 16-a is the clock pulse counter circuit, Figure 16-b is its time chart, and Figure 16-c is the counter. Clearing waveform diagram, FIG. 17 shows a copy size signal generation circuit, FIG. 18 shows a copy execution command signal generation circuit, FIG. 19 shows a copy execution signal generation circuit, FIG. 20 shows a pre-exposure strong illuminance lighting command signal generation circuit, Fig. 21-a shows the backward rotation command signal generation circuit, Fig. 21-b shows its evening time chart, Fig. 22-a shows the document table, forward and backward command signal generation circuit, and Fig. 22-b shows its time chart. FIG. 23 shows a paper feed start command signal generation circuit, FIG. 24-a shows a jam occurrence detection circuit, FIG. 24-b shows a jam timing signal generation circuit, FIG. 24-c shows their time chart, and FIG.
The figure shows a signal generation circuit for controlling conduction, Figures 26-a and 26-b show circuits for switching conduction to each terminal, 48A, 48B, 48C, 71, 72 are magnetic sensing elements, 161 and 162 are magnets, and in Fig. 22-a, CBHP: document platen home position signal, CCMD: copy execution command signal, CLCK: clock pulse signal, CEX
C: copy execution signal, 4CP: counter pulse signal,
324: Binary counter, CBFOR: Original platen forward command signal, CBREV: Original platen backward command signal, B5C, A
4C: Cassette size signal, B5BP, A4BP, B4
BP: Original platen position detection signal, CBBP: Original platen reversal position signal, STOP: Reset signal.

Claims (1)

[Scope of Claims] 1. A reusable endless rotating body, forming an electrostatic latent image on the rotating body, developing the latent image, transferring the developed image to a transfer material, and moving the rotating body. a plurality of process means for cleaning; a driving means for rotating the rotary body for latent image formation, development, transfer, and cleaning; a first counting means for counting clock signals having a constant ratio of numbers, and outputting the count signal at a timing of the clock signal different from a number corresponding to one rotation of the rotary body; and a process start timing. a second counting means for counting clock signals and outputting a count signal in order to determine the rotational body, and a rotation driving means based on the count signal of the first counting means to stop the rotating body at a position different from the initial stop position. and a second control means for controlling one of the process means according to the count signal of the second counting means so that the rotating body rotates by a predetermined amount after starting rotation and starts image formation.
An image forming apparatus having a control means.