JPS6095452A - Image forming device - Google Patents

Abstract

PURPOSE:To make a proper jam discrimination, and prevent malfunction and obtain an excellent image by controlling a process of image formation with a timing signal, and judging on whether transfer paper is discharged within a prescribed time or not and detecting a jam. CONSTITUTION:Sequence control over image formation is performed with a timing signal according to a control program from ROMs of a CPU. Probe signals O1-O3 from the CPU are inputted to a matrix circuit, and PEP (paper empty signal), LEP (liquid empty signal), size signal, etc., from respective detecting elements, microswitches, etc., are inputted to I1, I2, I4, and I8 and process to otutput driving signals from an output circuit. A jam check is made repeatedly with a signal JAMK to decide that a jam occurs unless paper is discharged within the specific time; and a fixing heater is powered off and a main motor stops, but a platen stops at its home position. Consequently, a proper jam decision is made and malfunction is prevented to obtain an excellent image.

Description

[Detailed description of the invention] The present invention relates to an image forming apparatus such as a copying machine.

To explain an example of a copying process of a copying machine to which the present invention is applied, the surface of a photosensitive drum, which has a photosensitive member consisting of a conductive layer, one light guide layer, and an insulating layer, first forms a primary band as the drum rotates.
uniformly pre-charged (for example, positively charged)
Next, as the document table (or optical system) moves, the light image is scanned and projected, and at the same time, the static electricity is removed by a recharging device with alternating current (or direct current with the opposite polarity to the precharging device), and the static electricity changes depending on the brightness of the optical image. A latent image is formed. Further, the latent image is entirely exposed to light to form a contrast electrostatic latent image, which is then visualized by a developer mainly containing toner in a developing device. After that, the visible image is easily transferred by a corona discharge with the same polarity as the toner (for example, negative if the previous charge is positive), and is transferred to plain paper and fixed on the transfer machine by a heater while being transported. be done. On the other hand, developer such as colored particles remaining on the surface of the photosensitive drum after transfer is removed by a cleaning blade, and residual charges are removed by a lamp and a corona discharger, making it possible to repeat the photosensitive drum. By repeating the copying process as described above, a desired number of copies can be obtained.

Conventionally, circuits have been constructed using transistors (referred to as TTT) to control the process sequence described above, but 'rqr' has a small noise margin,
It is extremely susceptible to noise, especially in devices that use high voltage such as copying machines. Therefore, as a noise prevention measure, many RC filters (filters made of resistors and capacitors) are used, and the number of parts increases, resulting in a complicated circuit configuration.

Furthermore, when configuring the control circuit, it was necessary to create complex logical expressions, which increased the design time.

Further, depending on the copy size, an additional circuit configuration is required to reduce unnecessary operations of the process processor Pi and operate at appropriate timing.

Furthermore, control circuits constructed from so-called hard-wired logic circuits require a large number of elements due to their complicated control circuit configurations, resulting in high costs and disadvantages in that sequence control cannot be easily changed.

In detecting paper jams (hereinafter referred to as JAM) caused by poor paper feeding, it is necessary to distinguish between copying one or multiple copies of different paper sizes, resulting in a complex circuit configuration and poor detection accuracy. It was also bad. In addition, in this type of control device, JAM detection malfunction is fatal, and a lot of time is required to design and study the prevention circuit as a countermeasure to prevent this.

Furthermore, when maintaining or assembling a copying machine, when checking the operation of the machine or performing heat running (test) without paper feeding, it is important to avoid killing the JAM detection circuit or paper presence detection circuit. In a control device such as TTL, each detection circuit is independent, so the operation for this is complicated. Furthermore, when making various long and short time timer circuits that are absolutely necessary for controlling a copying machine, independent circuits are required on each side, making it particularly expensive to make a long time timer.

The present invention is to provide an image forming apparatus that eliminates the above-mentioned drawbacks, and the present invention also provides a copying surface using a liquid development transfer method that allows good images to be obtained at all times. Another object of the present invention is to provide an image forming apparatus that can efficiently use an endless photoreceptor and produce stable images, and another object of the present invention is to provide an image forming apparatus that performs appropriate sequence timing processing according to the size of the formed image. ," Another object of the present invention is to provide an image forming apparatus that appropriately performs jam determination according to the size and number of images formed. The present invention also provides an image forming apparatus that performs stable control by preventing malfunctions of a control computer. Another object of the present invention is to provide an image forming apparatus that produces stable images regardless of the time the apparatus is left unused.

That is, an exposure operation means such as a document table or an optical system to form an electrostatic latent image on a rotating body such as a photosensitive drum or a belt, means for generating a plurality of reference signals such as the reversal position of the scanning means, and the like. It is characterized by having a control means CPU which performs sequence control of the process processing load based on the contents of a memory such as FLOM which inputs a reference signal and stores sequence steps for image formation.

Furthermore, in addition to the reference signal, clock pulses obtained by the rotation of the rotating body are input to the CPU to perform appropriate timing processing for pre-processing, process cycles, and post-processing.

Furthermore, a size signal is input to the CPU to perform timing processing and jam determination according to the size of the process cycle and post-processing.

Here, the scanning means may be one that scans the rotating body with a light beam to form a latent image, and the reference signal is obtained after constant scanning.

The photoreceptor may be a two-layer photoreceptor without an insulating layer, and a Carlson process may be applied to the image forming process.

Also, the clock pulse is, for example, 15.7 per rotation of the drum.
It is configured to generate 5 pulses. By doing this, the J Niridrum can complete one complete revolution or slightly over in counting 16 clock pulses.

This means that during the pre-processing or post-processing (described later) of the nB photoconductor before and after the copying cycle, unprocessed areas can be eliminated, and therefore any arbitrary part of the photoconductor can be removed, which is an advantage of the endless drum. It is possible to start the copying process from

(Pre-processing) 1) Pre-exposure: The photoreceptor has different photosensitivity characteristics depending on the prior history of the optical device Ω·1. 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, the characteristics of the photoreceptor plate are made the same for the first sheet and subsequent copies due to the fatigue effect of the photoreceptor.

2) Furthermore, as will be described later, if the toner is left unattended after copying, toner may adhere 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 is charged at high voltage with various potentials, the surface potential and polarity of each part of the photoreceptor are different, and if left in this state, it will adversely affect the characteristics of the drum. It is desirable to eliminate static electricity on the surface using, for example, AC corona. Furthermore, if the drum is stopped at a fixed home position, such as a conventional photoreceptor with ends, the stopping position is always fixed, so the effects of corona charging will accumulate in the same area, and the drum cleaner will Since the photoreceptor is pressed against the drum under considerable pressure, it is inevitable that the same portion of the photoreceptor undergoes physical deformation. However, as in the present invention, by generating an appropriate lock pulse for each rotation of the drum, the stop position of the drum as well as the start potential 11t are gradually shifted, and the cumulative effect of the above-mentioned negative effects can be avoided, and the photoreceptor It can be used evenly over the entire length of the photoreceptor, contributing to longer life of the photoreceptor.

The operation of an exemplary copying machine of the present invention will be explained below with reference to FIGS. 1 and 2. First, when the main switch 1o is turned on, the digital control circuit 1-1 is reset, and other electrical systems start up, so it takes a short time (about 4 seconds here), and then the photosensitive drum 1 rotates the photosensitive drum 15, which will be described later. Approximately 1 per revolution
A clock pulse generation mechanism is provided in a part of the drive system to generate six clock pulses. When the photosensitive drum 15 begins to rotate, the drum first rotates once or approximately once for 16 clock pulses (hereinafter referred to as 160 Petc). This can be considered as a step before entering the copying process, and may be omitted in order to make a high-quality copy when the copying process begins. Here, if the copy button 13 is turned on, the copying process will proceed directly.

First, when you turn on copy button 13, the previous 16 CP will be added plus 3.
The photosensitive drum 15 rotates by the amount of CP, and then the original platen 2 with the original placed on the original platen glass 5 starts, is illuminated by the illumination lamp 16, and its image is reflected on the reflecting mirror 17.
, the drum 15 is exposed at the exposure section 19 by the in-mirror lens 18.
image on top.

The photosensitive drum is equipped with a seamless photosensitive member on the circumference of the drum to increase the efficiency of surface use. The surface of the photosensitive drum 15, that is, the photosensitive layer, is covered with a transparent insulating layer.
It is fully charged by the corona current from the Subsequently, when the exposure section 19 is reached, as mentioned earlier, the illumination lamp 1
The image of the subject irradiated on the photosensitive drum 15 is slit-exposed onto the photosensitive drum 15. At the same time, AC high voltage is being supplied from the high voltage power supply 20.

AC charging is performed by an AC charger 22. Then, a high-contrast electrostatic latent image is formed on the drum surface by the next 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 a developing solution 25, stirs the developing solution, and performs development. 11 The pump 27 that pushes up to the pole part, the developing electrode 28, and the drum 7 rotate very close to the drum in order to remove the fog if there is a fog in the developed image, and one side is grounded. The electrostatic latent image formed on the photosensitive drum 15 by the electrode roller 29 is developed by the toner in the developer 25 pushed up to the developing electrode 28'' by the pump 27.

Next, the post charger 30 receives a high voltage charge from the high voltage power source 20 and squeezes out excess developer from the photosensitive drum 15' without disturbing the image. Next, the transfer paper 7 fed from the paper feed section comes into close contact with the photosensitive drum 15, and the transfer charger 31
The photosensitive drum 1 is exposed to the electric field caused by the high voltage from the high power supply 20.
The image on 5 is transferred onto transfer 7. After the transfer, the transfer paper 7 is separated by a separation belt 32 and guided to a drying and fixing section 33. The photosensitive drum 15 is pressed into contact with the blade cleaner 34.
The remaining toner developer is wiped off at the edge portion 35, 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 (FIG. 3) provided at both ends of the photosensitive drum 15, and is used again for development.

Here, turn on the main switch 10 mentioned earlier and
To explain why the document table 2 only begins to move after the drum has rotated by the amount equivalent to CP, and the drum has rotated by 16 CP + 3 CP, this machine uses an endless type drum as the photosensitive drum. for that,
Any surface of the photosensitive drum can contribute to image formation. Therefore, if you want to increase the number of copies per hour by eliminating unnecessary rotations as much as possible, if some toner remains in the blade cleaner edge 35 for the first rotation of the drum, this machine will last for a week, for example. In the worst case, the photosensitive drum dries out when not in use and becomes stuck to the drum, in which case it is necessary to clean the photosensitive drum before forming a latent image.

Next is 3CP, which is because there are 10 charging steps before the slit exposure in the copying process mentioned earlier, and the cleaner edge part mentioned above is added to the first copy. This process is based on the idea that avoiding this will make the machine more reliable.

The transfer paper 7 is stored in a cassette 6, which is removably attached to a paper feed section at the lower left of the machine, and various types are prepared depending on the size of the transfer paper. When the document table reaches a predetermined position, an actuating piece 161 (FIG. 4) 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 to operate. descends and comes into contact with the topmost transfer paper in the cassette 6, and by the movement of the separation claw 39, one sheet of transfer paper is separated and sent out from the sumo wrestler 6.However, the register rollers 41 and 42 located immediately nearby are paper feed rollers. transfer paper 7 fed out from the cassette 6.
creates slack between the guides 43, 44 with their tips touching the contact portions of the register rollers 41, 42. Then, when the paper feed roller is about to rise, the registration roller 41 is moved again at the leading edge of the image on the photosensitive drum.
42 rotates, and the transfer paper 7 is sent at a speed that matches the circumferential speed of the photosensitive drum 15.

Next, the movement of the document table will be explained. Place the original to be copied on the original platen glass 5 with its leading edge aligned with the leading edge A of the glass, press it with the pusher cover 3 (Fig. 1), and press the copy button 13 (Fig. 1). 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 9 CP from the clock pulse generating mechanism, and performs slit exposure. When the exposure is completed, the document table 2 stops moving to the left in response to a signal from the document table 2 itself according to the paper size in the cassette, and immediately returns to the opposite direction, that is, to the right. 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.

Since the return speed is high as described above, a shock is likely to occur when stopping, but in this machine, the shock is absorbed by the brake mechanism and the document table 2 is quickly stopped at a predetermined position 11t. A counting device (not shown) linked to the copy button 13 makes it easy to make multiple copies of the same document in succession.

Restarting the document table during continuous copying is performed immediately after the document table 2 has stopped at a predetermined home position. The copy button remains on until the number of copies set in the number of copies setting field (FIG. 1) is fed. Further, the copying machine of this embodiment is capable of making copies of various sizes from the maximum B4 size to the minimum B5 size. In such a case, the document table 2 is set to B4, which is the maximum copy size, regardless of the copy size.
, the number of copies per unit time is small and the time loss is large. Therefore, this copying machine supports each copy size, for example, A4. A plurality of document table reversal signal generating members 48A, B, and C (corresponding to B5) are provided (FIG. 4), and the copying cycle is changed in accordance with each copying size to improve copying efficiency. The difference in cycles depending on the copy size as described above is determined by signals from the cassettes 6 for each size.

Next, the suspension state and restart after copying is completed will be described.

If the power is left on after all copying operations are completed, the photosensitive drum 15 will constantly rotate, and if the high-voltage power is turned 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, when a certain copying operation is completed and the next copying operation is not performed even after a certain period of time has passed, the main switch 10 is turned off.
Even if it is N, the drum automatically stops and enters a rest state. 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 copy during this hibernation state, press the copy button 13 on the operation section 9.
When is pressed, everything returns to the state before the pause Ml l-, the drum rotates, and after QCP, the document table 2 starts to move forward. When the copy button 13 is pressed during this pause, the high voltage power supply 20 is turned on and the photoreceptor 15 starts rotating.

Before the copy button 13 is pressed, the potential on the photoreceptor 15 is maintained at a uniform potential by the AC static eliminator 22. Then press the next copy button 13. Charger 30, transfer charger 31
When the photoreceptor 15 starts rotating, - the charger 30,
The area between the ten transfer chargers 31 is charged to ten, and the potential after the - charger is neutralized by the ten chargers 31. Therefore, there is an extreme potential difference in the photoreceptor 15-1 near the charger 30, and if this area enters the image forming area, it will have an adverse effect on the image.

This charger 3 starts from the AC static eliminator 22 where image formation begins.
Converting the distance to 0 into the number of clocks, the number of clocks that does not affect the image is 9. It is CP.

FIG. 4 shows the drive system and signal generator.

At the two ends of the rear frame 50, members 73 and 74 for attaching the control signal magnetic sensing elements 48, 71 and 72 are fixed. (Figures 2 and 3) Guide rail mounting base 73
．． 74 has magnetic detection elements 48A, 71, 72.48B,
48C is fixed, and control signals are sequentially outputted by magnets 161 and 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. Further, the document table moves forward, and the exposure of each copy size (Bs, A4, B4) is completed, and the magnet 161 moves to the element 48A, 48B, or 48C.
When it reaches the top, a reversal command is issued, and the document table 2 moves from forward movement to backward movement.

As the backward motion progresses and the magnet 162 reaches the element 72, the document table 2 is stopped at a predetermined position in response to a stop command. The size switching command is issued by the cassette 6.

In the clock pulse generation mechanism, a gear 113 is integrally fixed to a sprocket wheel 112 that is driven via a chain 86 from a sprocket wheel 85 attached to the main motor M1, and the gear 113 is connected to a clock pulse generation magnet 163. The magnet engages with the gear 115 fixed to the arm 114 holding the main motor M, and rotates the magnet. Generate clock pulses.

Next, we will discuss the operation when paper feeding is defective.

In the copying machine of this embodiment, the transfer paper is
The printer is equipped with a jam detection means to check whether the transfer paper has completed the separation and fixing process and is ejected from the machine within a predetermined time. The system is designed to stop the machine if it is not discharged within the specified time to prevent accidents such as fire. The method of detecting the presence or absence of transfer paper is such that when the transfer paper passes through the fixing heater 124 and reaches the paper ejection roller 46, the transfer paper is placed coaxially with the paper ejection roller 46. Boost TAM kenkoro 180. Then, the lever 181 is pushed upward to the left, and the tip f1 of the lever 181
] The magnet 130 shown in step 1 is also pushed up, moves away from the fixed magnetic sensing element 129, and outputs a signal.

When a jam is detected, the fuser heater is turned off and the main motor M stops, so the drum 95 stops, but the original platen 2
stops after returning to a predetermined position (home position). When stopped, the upper cover 127, which can be opened around the hinge 131 in FIG. 1, opens vertically together with the duct 128. In this state, if there is nothing left on the hot plate 124 and a jam occurs in the fixing section, the upper cover 124
Once opened, the transfer paper can be easily removed by hand. Next, it is rotatably supported by a shaft 132 together with the separating section including the hot plate 124, and is usually held in place by a locking mechanism 133, and is rotated around the shaft 132 by removing the locking mechanism after opening the top cover 127. It rotates clockwise, and the transfer paper path after the register rollers 41 and 42 is opened.
Jammed transfer paper can be easily removed by hand. At this time, the separation belt 32 separates from the photosensitive drum 15, so that it is easy to remove the transfer paper jammed in the separation section.

After removing the jammed transfer paper, perform the jam release operation and close the upper cover 127.'' The machine returns to its original state.

Next, a method of attaching the cassette 60 to the main body 1 will be described. When the Ube 145 of the cassette 6 is placed on the '7144 fixed to the fuselage and the cassette is pushed into the fuselage, a spring 149 having a roller 148 is arranged so that the protrusion 146 at the bottom of the cassette hits the positioning plate 147 of the cassette stand. As a result, the cassette 6 is pressed into a predetermined position.

At this time, the cam 150 installed on the side wall of the cassette and the micro switch 1'51 installed on the cassette stand 144 (
MSI) and 152 (MS2) output a cassette loading signal and a size signal.

Next, FIG. 6 shows the overall circuit configuration for controlling the operation of each device in this copying machine. Computer ■I+I2. I. ,
Signals are input to the device 8 as input signal groups from each of the aforementioned magnetic sensing elements, microswitches, etc. 01~0
4 outputs signals for driving pulse transformers, small lamps, solenoids, electromagnetic clutches, etc. as an output group.

In the center is a microcomputer that processes signals from the input signal group, and since the microcomputer performs time-series processing, it must read one input signal from many input signal groups. Therefore, the signal is used as a microcomputer probe signal, inputted to the matrix circuit (FIG. 15), and the microcomputer reads one signal from (1) to (8). The microcomputer processes the read information and performs the 11th process described below.
The signals are sequentially output to the output terminals θΔ to θ15 according to the flowcharts shown in FIGS. This output signal is input to the output control circuit (FIG. 16), subjected to logic processing, and then output as an output signal group to drive each load.

The microcomputer will be explained with reference to FIG.

Figure 7 shows the microcomputer TMS- made by TEXAS.
1000 is an internal circuit block diagram. Among them, TiL
The OM is a read-only memory in which the sequence contents of the multiple qI device shown in Figures 11 and 12, which will be described later, are pre-ordered in code and stored in each address, and the contents can be retrieved each time an address is set.

The control contents are stored in binary code 81:+it from address 0 to the desired final address.

RAM is a read/write memory that temporarily stores data and the like during program execution, and is a memory that stores one set of binary codes. More specifically, as shown in FIG. 8, each bit is constituted by a flip-flop, and a set is selected by an address designation signal, and data is written to or read from a plurality of flip-flops within the set. T(, A M r
The address of information stored in lt is specified by the X register and the X register. In addition, Cp 11 is an AL that has addition/subtraction logical operation functions to decode input data and process data.
U, a program counter PC for specifying the address of an instruction stored in the ROM, and a page address register PA for specifying a page address group of instructions stored in the ROM.

The page buffer PB1 subroutine for changing the ROM page is called, and the execution of the subroutine is completed.
Subroutine return register SR for storing the original return address, accumulator AR for temporarily storing the ID operation result for decoding instructions stored in ROM
It is composed of etc. Input terminals I,, I2. I,
, I.

is connected to INPUT, and output terminals 01-0, , are connected to Ol R, 0VTPvT.

To give an overview, the CPU first specifies the address of the ROM in which the sequence is programmed, the contents of the specified address are read into the CPU through the data line, the CPU decodes this, and according to the decoded contents, the program starts from power-on. Sequentially, in chronological order, sometimes the data is processed within the CPU itself, sometimes the data in the CPU is stored at a specified address in R and AM, and sometimes the data is stored at a specified address in RAM. Sequence control is performed by inputting data into the CPU, sometimes outputting data in the CPU to an output signal line of an output section, or inputting data into the CPU from an input signal line of an input section.

The basic timing for TMS 1000 program processing is shown in FIG.

The several μsec clock 0 (from the OSC in FIG. 8) in FIG. 9 is the basis of program processing.

That is, it takes two clocks to decode the program counter, two clocks to specify the decoded ROM address, and at the same time, the program counter PC is +IL, R.
, 1 clock is required to decode one program instruction in OM, 1 clock is required to write to I''LAM, and total i
tl' One instruction is completed in 6 clocks. The programmed instructions following the above address are executed at similar time intervals.

(Input Code) The number of status signals input from the copying machine is large, and the number of bits of the input port of the computer is not equal to 4 bits, so the matrix circuit shown in FIG. 15 is provided as a converter. Table 1 shows the relationship between probe terminals θ1-3 and input ports 1-I8.

Table 1 CLKP is a clock pulse (generated in synchronization with the photoconductor), PEP is a paper out signal, LEP is a liquid out signal, C3T
P is the copy button, CBHP is the document platen home position, TSC is the toner supply command, PDP is the paper detection signal (transfer paper), B5゜A4, B4BP is the document platen reversal signal for each paper size, MSI, MS2 is the micro switch (paper (for size detection), JAMK is JA, M undetectable.

In addition, the input yy-1-t is the drum clock CT, K
P and an idle time signal TJD EN (described later) are input.

In Table 1, the status from the input signal group changes every moment,
The computer reads B1°θ2. at the time you want to read it. A probe signal is output to any of θ3 (these θ1, θ2, .
θ3 signals are not output at the same time) The desired state signal is 4
1) i 1. (T1+, T2゜I,, I8 parallel)
and determine whether the content of I) i + is 1 or O.

By repeating this operation in chronological order, it becomes possible to judge the input state signal that changes from moment to moment.

Figure 15 shows the IJ rack circuit. 300～
308, 310, 311. , 313, 314 are Nant gates, 309 is an inverter, and 312 is an OR gate. The terminal numbers of the circuit correspond to the numbers in FIG.

This will be explained using an example of data reading when the cassette runs out of paper and lighting of the paper out indicator lamp.

This paper-out signal is obtained from a combination of a lamp and a light-receiving element set near the cassette attachment in the main body. When the paper runs out, the resistance of the light-receiving element decreases and the detection circuit outputs a paper-out signal (P EP = 1.
) is output. Therefore, the input 3' of the NAND gate 300 of the matrix circuit becomes 0 level. On the other hand, NANT)
A probe signal θ1 from the microcomputer shown in FIG. 6 is input to 4' of 300. This PEP belief υ is read from the input terminal 2 by setting B1. Reading other input signals 6 Follow Table 1.

In the control flow, reading paper, etc. is performed at 5TEP in Figure 11.
The command is executed at 5UB2P of 8, and when the program progresses to 8TEP8, a level is set in B1 every time 5UB2P is passed, and 01 is reset to O level immediately after reading is completed. . The time from when B1 is set to when reading is completed is approximately 60 μsec.
It is.

While this B1 is set, other reading probe signals θ2. θ3 is at 0 level.

That is, since θ1 is now set, NAN in Figure 15
Input 4' of D300 becomes 0 level, and output of 300 becomes 1. The output of NAND308 becomes 0 level. This is because the input of the pond 308, that is, the output of 303 and the output of 307, is a level because B2 and B3 are not set.

The output 24' line of this 308 is input to the microcomputer shown in FIG. 6 and read by the 5UBLP program. The read data is stored at address 0 BITI (hereinafter referred to as (0, 1)) of the Y register in the RAM area shown in FIG.
is stored in SUB LP determines whether BITI is 0 or 1, and when it is 0, a paper out signal is output as a rubel to B13 in FIG. When the label is output as shown in FIG. 16 34', the buffer inverter 432 is turned on, the output of the buffer inverter 432 becomes 0 level, and the paper out indicator lamp lights up.

If there is paper in the cassette, the input 3' of 300 in FIG. BITI of the figure RAM becomes Lebel.

If BITI is Lebel, it is determined that there is paper, so no paper out signal is output to B13.

In each of the above program steps, the data of other input groups is read and judged in the same way, but in Figure 15 (Ma)
The input group signal of the IJ rack circuit and the logic gate 310 are P
EI', CnLTP, BP double signal on, aii is LT
;! T', 'rsc, MS 1 signal 0J31
3 is for supplying C5TTF, PI)P, and the OI(,,,) of the MS2°JAMK signal to the CPU.

The feature of the IJ rack path embodiment is that the document table reversal signals for each paper size, namely B5, A4, and B4, are input to the OR circuit, and only one reversal position signal is provided on the IJ rack. There is no such thing. Normally, the number of input signals to be controlled should be 11, but in this case, the number of probe signals must be increased by one, and there is a limit to the load to be controlled, so only three probe signals can be used. It has become.

However, at the same time, we focused on the fact that document table reversal signals for different paper sizes were not input, and used a method to store the paper size in the R and AM areas in the size subroutine, thereby distinguishing document table reversal position signals (described later). ) is adopted. This has the effect of requiring only three probe signals.

Next, the output circuit will be explained with reference to FIG. The terminal numbers of the circuit correspond to those in FIG.

In Fig. 16, inverter 4o2, inverter 40
5. The circuit composed of resistor 401, resistor 406, capacitor 403, and capacitor 404 is a 5 KHz oscillator. This oscillator uses a triac (not shown) to drive an AC load such as a main motor, and uses a pulse transformer to trigger the triac. This is an oscillator for driving the triac. Therefore A. ND gate 4 0 9 , 4 1 0
, 4 1. i, 4 1 2 and 4 1 3 all serve as pulse transformer loads.

The output 52 is the 4-second timer output from the time the power is turned on. 76' is a main motor signal. This signal is at 0 level for 4 seconds after the power is turned on, and becomes a level level after 4 seconds.

The output of the inverter 407 is level for 4 seconds. On the other hand, the other three inputs of the AND 408 are developer motor signals, and output a level from when the power is turned on until post-processing starts.

Therefore, these AND signals output a level for 4 seconds from the time the power is turned on. After that, it will never reach level 0.

37, the document table moves forward and a paper feed signal is inputted before it reaches the reversal position of B5. When a paper feed signal is input, 37 becomes 0 level. On the other hand, 27 becomes a rubel when the document table moves forward. Therefore, AND4 1 5 outputs a paper feed signal only when the document table moves forward, and when the document table moves backward, the signal is input at the same position 37 as when it moves forward; Since it is at level, no level is output to AND415.

Inverters 416 to 429 are Darlington type transistors for driving a load, and drive the load with an input signal.

Next, the contents of the loads on the inverters 416 to 429 will be shown.

Table 2 Inverter 416 is an all-over exposure lamp (AEXP).

417 is in front of Russia (PEXP).

418 is AC static eliminator (HVAC) to the main motor (DRMD).

419 is the document platen advance motor (C B FW).

420 is l backward % - data (CBR, V) [.

421 is a ten-form charger, a -charger, a ten-transfer charger (HV
DC), fJXmW! , the light 5>pu (IEXP) 422 is turned into a blank exposure lamp (BEXP).

423 is the developer motor (DVT, D).

424 is Power Ho/L/Do IJ Ray (T'TT
CD) to.

425 is paper feed clutch, paper feed counter (PESD/CNTD) 426 is the toner empty indicator lamp (TET,).

427 is on paper (PET, ).

428 is liquid (　L　ET,　).

429 is the JAM indicator lamp (JAMT,).

Connected.

The paper feed clutch is used to lower the rotating paper feed roller 4o onto the paper when the main switch is turned on, and the power hold relay is used to lower the paper feed roller 4o onto the paper when the main switch is turned on.
This turns on the LD. Also, flank exposure is the first
3. As shown in the time chart in Figure 14, the exposure lamp (
IEXP') is lit in substantially the opposite direction to eliminate the difference in the surface potential of the photoreceptor. The paper feed counter counts the number of copies that have been completed, and compares the cNTD signal every 10 signals with the set number of copies, and outputs a copy end signal (turns off the copy button) when the number of copies is the same. Figures 13 and 14 show time charts of input signals and output loads. Since it is clear from the figure, the explanation will be omitted.

Figure 10 shows a sequence control system flowchart.
Further detailed flowcharts are shown in FIGS. 11 and 12. FIG. 10 clearly shows the outline of power-on, process execution, and standby.

The terms "front rotation" and "back rotation" correspond to pre-treatment and post-treatment of the photosensitive drum surface. The pretreatment wipes away toner adhering to the drum surface and blade, contributing to the formation of a good latent image. Also, post-treatment can remove residual toner on the drum surface before it dries. Also, by keeping the charger in operation during pre-treatment and post-treatment, it is possible to reduce uneven potential on the drum surface. In this example, the blade remains in contact with the drum from beginning to end, but by making contact and non-contact depending on whether the power is turned on or off, the blade marks on the drum surface can be reduced.

[Reset] Following the power-on, the power-up reset (, Create T (PU-R8).These 4 seconds are created by the program.In other words, as mentioned above, R
The number of clocks required to execute one instruction out of the instruction group stored in the OM is 6 clocks. This clock frequency is 300 K due to O20 shown in Figure 8.
It is set to Hz. In other words, the time of one clock is T
From =1/'f (seconds), it becomes approximately 3.3 [μ5ec],
With 6 clocks, it will be about 20 [μ5ec]. Therefore, since it takes 20 [μ5ec] to execute one instruction, a 4-second timer is created using 200,000 instructions. That is, following power-on, 10 is put in RA, M area Y address 1, 15.2, 15.3, 15.4, and first the subtraction of the number 15 in ThAM area 1 becomes 0. Repeat until. If it becomes 0, RAM area 2
Subtract 1 from the 15 in the box to get 14. Then 0
Enter 15 again into RAM area 1, which is now . Then, the subtraction of RAM area 1 is repeated until it becomes O.

Each time it becomes 0, subtract 1 from the contents of R, AM area 2, and
Each time the area of AM2 becomes 0, 1 is subtracted from the area of RAM3, and the process is repeated until all of RAM areas 1, 2, 3, and 4 become 0. The numerical value of the I' (AM area) is determined so that the number of instructions during this period is about 200,000. In addition to this embodiment, a method for realizing this 4-second timer is shown in FIG.

The method shown in FIG. 20-1 is an oscillator that oscillates a signal at intervals of, for example, one second. A certain output signal of the microcomputer is used to read the oscillator signal into the microcomputer. For example, if the oscillator is used for one second, the microcomputer only needs to count four times, and the number of program steps can be extremely reduced. Also, 20
-The method shown in Figure 2 uses a clock generated in synchronization with the photoreceptor,
This is a method of counting this clock when the frequency is relatively low. The method shown in Figure 20-3 is a method in which the microprocessor driving clock frequency is reduced to a low frequency using a frequency divider and this frequency is counted. This method is effective when creating a highly accurate timer.

Also, since this copier will not be used for a long time, toner tends to stick to the cleaning blade if it is left unused, so if it is left unused for more than 7 hours, pre-processing will be performed more than usual (approximately 40 seconds). It looks like this.

Figure 21-1 shows the external circuit configuration for this purpose, and Figure 21-2 shows a time chart. The circuit configuration consists of a CR timer circuit, a reset circuit, a delay circuit, a comparison circuit, and a driver circuit.

To explain the operation, when this copier is in operation, the main switch (S
Since W) is ON, the capacitor of the CR timer is being charged via DC 24V. If the charging time is 30 seconds or more, the capacitor will be charged up, and this capacitor has very low leakage current. When the main switch is turned off, the capacitor starts discharging, and if the left time is 7 hours or more (time for the toner to stick to the cleaning blade), the potential of the capacitor decreases and the next time the main switch is turned on, the comparator (
CMP) is activated by inputting a potential below a predetermined value, turns on the output transistor for a time determined by a delay circuit (approximately 10 seconds), and outputs a long-time leaving signal LDEN signal.

When the delay time ends, the reset circuit works and starts charging the capacitor again. On the other hand, if the standing time is less than 7 hours, the capacitor potential is above the predetermined level, so the comparator does not operate.
The output transistor starts charging the capacitor again in the OFF state. The setting time is determined by the capacitance of the capacitor.

After the power is turned on, 5TEP1 is first executed in the manner described above, and the developing device motor is turned on. (STBP2) This developer motor can also pour developer into the vicinity of the contact between the blade and the drum surface, thereby dissolving dried toner on the reblade and drum and facilitating cleaning in pre-treatment.

Next, in 5TEP3, it is determined whether or not to disable the JAM detection circuit (hereinafter referred to as JAM killing).

JAM killing is often carried out when performing maintenance services on this copying machine to check the operation of the sequence without feeding paper. In this case, in computer control, unless the T A, M detection circuit is disabled, the JAM indicator lamp will operate and the sequence will stop, making it impossible to confirm the sequence.

Therefore, in this embodiment, if CPI is short-circuited to ground before power is turned on as shown in FIG. ) Enter 21'. On the other hand, Ma) IJ
Lebel is input to the rack path 1' from the output terminal 52 for 4 seconds after the power is turned on. Therefore, the output of NAND 314 remains at O level for 4 seconds. AND310 output ld,
It is a rubel for m(7). This is because the 4-second timer is created only by a microcomputer program, and θ
1. θ2. This is because the probe signal is not output from θ3. Then, the output of NAND311 becomes 0 level.

5TEP3 reads this O level. As will be described later, the information read in this 5TEP3 is stored in R and AM, and
This is used when determining whether the transfer paper has arrived at TEP38 in FIG. 2. Next, proceed to s'rgp4, determine whether the 4-second timer mentioned above has timed up, and when the timer has timed up, set 5TEP.
Proceed to step 5 and the load of the main motor etc. is turned on.

In the 8'l'' EP6, the LDEN signal is set at approximately 90 seconds after the power is turned on by the above-mentioned leaving time measuring circuit shown in Fig. 21.
Since the output is 0 seconds, the LD will be output 4 seconds after the power is turned on.
The computer reads the EN signal and flags one stroke of R and AM.At this time, the photoreceptor has not yet rotated, so C
LKP is not input.

Furthermore, after the 4-second timer ends, the PUR8 signal of AND201 becomes 0 level, so even if the LDEN signal level is input, the output of A, N'D 201 is 0 level, so the output of OR gate 202 is the photosensitive drum. Only the clock pulse CLKP signal generated in synchronization with is input to the computer.

After the 4-second timer ends, STEP (determine the contents of the data read in step 3 in step 5TEP7). If the left time is over 7 hours, the drum is further rotated in step 8TEP8.9 and pretreatment is performed for 40 seconds. During this time Only the load turned ON at 8TEP5 is being driven.If the left time is less than 7 hours, the preprocessing 40 second timer will not operate and 5TEP will be turned on.
10. Here, while the 40 second timer is not up, subroutine 5U13CBRV, SUB
Execute LP, SUB 8IZE.

This SUB CBRV, SUB T, P, 5UI3SI
While the 40-second timer is running, the ZE always detects if the document table comes into contact with the document table and moves out of its normal position, if there is no paper inserted in the paper cassette, or if a cassette with a different paper size is replaced midway. This is a routine for

These 5UBROUTBNs will also be used in subsequent steps.
are installed everywhere.

The 40-second timer generates a clock pulse (CLKP) in synchronization with the photoreceptor (one clock time fd approximately 0.5).
(seconds) by counting 80 clocks. 4
When 0 seconds of processing is completed, CL at 5TEPI 0.11
Count 10 KP. As mentioned above, this copier has 4
Preprocessing is performed once regardless of whether preprocessing is executed for 0 seconds. If you pre-processed for 40 seconds, repeat the pre-process once after this,
If you do not perform 40 seconds preprocessing, perform 1 preprocessing after PUR8.
Rotate. 5TEPI 1 determines whether 10 CLKPs have been counted.

This is to prevent the copy operation from starting until at least 10 clocks have been counted, assuming that the copy button is pressed during preprocessing.

FIG. 17 shows the details of 5TBPI 0.8TEP11. In FIG. 17, counting of 10 clocks is started at 5TEPIO-1, clock reading is started at 5TEP10-2, and it is determined whether the clock signal CLKP is level or 0 level. Now when CLKP is Rubel, S T EP
Proceeding to step 10-4, it is determined whether the document table is at the normal position (home position) before scanning. If it is not in the normal position, a document table back motor ON signal (output θ6 in FIG. 8) is output. Furthermore, it determines the paper size, monitors the loading of the cassette, and determines the presence or absence of liquid and displays a warning. If CL K P becomes 0 level, 5TEI'l0-7, S'rE
: ['l0-8 and repeat the same process. CT, K
Since r becomes rubel again, repeat this and set 1 in STEP 10-12.
Determine whether you have counted 0 Kurotsuta.

While counting the above 10 clocks, other controls are always possible continuously, regardless of whether the clock is level or 0 level.

This control method has since become the basic control method when performing other controls while reading CI and KP. This method is particularly effective when it is necessary to perform other tasks while counting the clock, such as when it is necessary to detect when the document table moves out of its home position. In other words, even if the document table is reversed by the reverse position signal, the home position is detected, and the document table back motor is turned off, the document table still protrudes from the home position (because the user of this machine touched the document table). Sometimes.

However, in order to correct this protrusion, if you want to detect the protrusion of the document platen when the clock is at the 0 level or level, for example, if you create a program that detects the protrusion only at the O level, the document platen back motor will be activated when the clock is at the 0 level. An attempt is made to turn on the document table and return the document table to the stop position, but during the return, the document table back motor remains ON even if the clock changes to the clock, so there is a risk that the back motor will be overloaded.

Next, after the CLKP10 count ends, STEP 12 is executed to check whether the copy button is pressed. If the copy button is not pressed, STETI 3, ST
Run EPl 4. If the copy button has been pressed, the process advances to STE'I'21 to execute the copy process.

When one rotation of preprocessing is completed, proceed to STIi3P15 and ST
Turn off all but the main motor, high voltage AC, and blank exposure that were turned on in EP5.

Then, the process moves to the post-processing step described above.

During this post-processing, the potential on the photoreceptor is made uniform.

During this post-processing, even if the main switch is turned off, a power hold signal is generated to maintain the power supply to the control circuit.

Even during post-processing, s'rEp16 is executed to detect whether the copy button is pressed, and the drum rotates twice for post-processing, that is, 32 clocks are counted. If the copy button is on, the process advances to step STEP21. When the post-processing is completed, the copying machine goes into standby mode. This is why all loads are turned off in STEP 19.

During standby, it is necessary to always detect whether the copy button is pressed, and this is executed in 5TEP20. Copying machines are often left in this standby mode for long periods of time, but since the temperature inside the machine is higher than the room temperature, toner adhering to the cleaning blade tends to stick.

Therefore, there is a possibility that the next image formation will be adversely affected. Therefore, during standby, the clock is counted using the means shown in FIG. 20, and after several minutes have elapsed, the main switch is turned off.

Next, when the copy button is pressed, it is determined at 5TEP12, 16°20, and the process advances to 5TEP21, where the load shown at 5TEP21 is turned on and the drum rotates.

And in order to avoid the drum area that has a negative effect on the image, 9
Do a clock count. 5TEP22 is a step for determining whether the stop button is pressed and the copy command is interrupted. If the process is not interrupted, the CBFW signal is outputted from the output terminal θ5 after 9 clocks have been counted in step 24, and the document table is moved forward. Since the minimum paper size is B5 size, the document table first reaches the B5 inversion position. Then, the signal B5BP is output.

The paper feed signal PE5P is obtained from a Hall element provided at a position before the reversal position of B5 as the document table moves. When B5BP is confirmed at STEP 26, the S U n T S L routine is performed at 5TEP 27 to detect the developer concentration. If the developer concentration is low at this point, a toner out flag is set in the RAM and used for sequence processing to be described later. Next 5TEP2
In the paper size determination routine No. 8, it is determined which paper size cassette is currently installed.

As mentioned above, this is a microswitch MSI.

A paper size signal is created by combining MS2.

There are four possible combinations, but this copying machine uses three sizes, so the remaining one is used as a signal when no cassette is installed.

When the paper size is determined in 5TBP28, the size flag is set in the RAM and the flow branches to one of the flows related to B5, A4, and B4 sizes (FIG. 12).

It is recommended that the drum surface be cleaned by rotating the drum for 9 clocks or more after pressing the copy button.

The B4 size will be explained in detail below.

At 5TEP84 in FIG. 12, it waits for B5 to pass through the reversal position. A magnet provided on the document table for detecting the inverted position of the document table has a certain width. Therefore, it takes a certain amount of time (several hundred m5ec) for the document table to pass over the Hall element.
It takes. During this time, the microcomputer executes the previous paper size determination routine. Then, it waits for a sheet of paper size other than the desired size to pass through the reversal position.

That is, for the A4 size, the fall and rise of the signal of the B5 back position detection Hall element are detected, and for the 4 size larger than A4, the B5. By detecting the fall and rise of the signal of the Hall element for detecting the A4 inversion position, its passage is determined (STEP 84.85.86). And 5TEP
When it is determined by 87 that the original platen has reached the reverse position of B4, 5TEP88 turns off the original platen (, 1 unit forward signal CBFW, blanking lamp 131':
Output BRV.

Next, 5TBP89 is the accumulated jam detection routine PDPI, and when the document table reaches the reverse position of B4, the paper detector 18
o (Fig. 1), it is determined whether paper is detected or not, and when the transfer paper ejected from the previous process remains in the machine, the progress of process 5TEP is stopped, a stagnation alarm is issued, and the next paper feed is started. make it stop. This is effective during continuous copying.

If the paper is not retained, it is determined by s'rnp9o whether the original table has returned to the home position, and when it has returned, the document table stops moving backward (STEP91), and the process proceeds to a paper delay jam determination routine PDP2 (STEIP92).

Note that the subroutine TSSD is executed between the determinations of B4BP and the original platen stop position. This routine is 5TEP
The flag set in the RAM in the 'I' S L routine of No. 27 is reset when the developer concentration is recovered when executing 5TEP87°90.

Also, the JA, M detection FDP2 routine of 5TEP92 is a delayed JAM detection, and after determining that the previous sheet of paper has not accumulated in 5TEP89, next time C, the transfer paper that has been transferred and is about to be ejected is inside the machine. Detects cases where the paper is not fed due to a paper jam or a misfeed. That is, if the transfer paper has not reached the JAM detector at the time of 5TEP92, a delay alarm is issued and the next paper feeding is stopped or the machine is stopped. 5TE
If P92 determines that it is not jammed, 5TEP9
Proceed to step 3 and check the copy button to determine whether to copy one copy or multiple copies. If one sheet of metal plate is to be copied, 5TEP94.5TEP95, which counts 7 clocks, is executed. This is a program that prepares the timing for entering post-processing 5TEP■. Since relatively short paper such as B5 size paper is ejected earlier than B4 paper, etc., it enters post-processing in less than 7 clocks. Note that even if the paper size is different, post-processing always begins when the trailing edge of the paper finishes passing through the paper ejection roller.

Also, post-processing is performed regardless of the paper size.
The timing can be changed so that the post-processing starts at the lock position from the back position of 5.

5TEP96 performs a determination that there is no replenishment toner.

It is a routine place. This judgment is made by changing the flag set in STEI'27 when the developer concentration is low at the back position of B5 to s such as 5TEP87°5TFP90.
In UDTsSI), when the developer concentration is too low to reset, the concentration is determined again just before starting post-processing, and if the developer is low, a toner empty warning is issued. .

Since the time from the back position of B5 to the start of post-processing is long, even if the developer concentration is M <, if there is replenishment toner, the concentration will be restored to the specified concentration immediately after replenishment. Input signal T at that time
SC becomes a signal that the toner is thin for a long time, that is, there is no replenishment toner.

This is explained in detail in the ATR circuit of FIG. 19-1 and the flowchart of FIG. 19-2. No. 19-2
The figure is shown for B5 size. In FIG. 19-1, 501 is a circuit for determining the concentration of the developer, and if the concentration of the developer is low, the output of 501 becomes a level. On the other hand, the period in which toner can be supplied is from the time when the document table moves forward until the start of post-processing. If there is no toner supplyable section, for example, if the main switch is repeatedly turned on and off, a signal indicating that the toner is thin may be output each time. This is because the liquid concentration is determined by irradiating the liquid passing through the slit with a lamp, receiving it with a light receiving element, and detecting the change in the resistance value of the light receiving element. In this case, when the main switch is turned on, the developer motor begins to rotate and the lamp lights up before the liquid flows into the slit. This is equivalent to the fact that the resistance of the light receiving element is small and the concentration of the liquid is low, and the toner is supply it. Therefore, if the main switch is repeatedly turned on and off, the concentration of the developer becomes abnormally high, which adversely affects the image.

Even if the gold wave concentration is low and the output of 501 is 1, the signal TSC is short-circuited to ground because transistor 506 is turned on. This is because the signal 07 from the microcomputer is at the 0 level, so the output of the inverter 508 is 1, and the transistor 506 is turned on.

On the other hand, when the document table moves forward at 5TEP25-1,
At the next 5TEP, a toner replenishment enable signal is output. Therefore, for the first time at this time, the output of the inverter 508 becomes 0 level, the L transistor 506 is turned off, and the output signal of the operational amplifier 501 is supplied to the transistor 502.
The toner supply solenoid 503 is activated.

However, if there is no toner, the output of the operational multiplier 501 is 1, the output of the inverter 505 is 0, and a signal indicating that the toner is thin is read into the microcomputer through the matrix circuit. That is, the out-of-toner flag is memorized in the R and AM areas in the TSL routine of 5TEP27, and the flag is not reset in the TSSD routine of 5TEP30.41. After the JAM judgment is completed and post-processing is started, immediately before that, the toner empty flag is stored in the R and AM areas. In the case of B4 size, at 5TEP96), the setting of the flag in the RAM area that was previously set is determined and a message indicating that there is no toner is displayed.

When JAM detection and toner out judgment are completed, 5TEP50
Alternatively, the process moves from 96 to (2) in FIG. 11, enters post-processing, and repeats the above-described operations.

We have just explained one-sheet copying, but in the case of multiple-sheet copying, when the document table reaches the home position and it is determined in 5TEP93 that the copy button is still pressed, Figure 11 ◎
Then, turn on the document table advance signal again and repeat the same process.

Up to this point, we have explained the sequence for B4 size, but the sequence is the same for B5 size and A4 size, and the only difference is the JAM detection method, so we will omit the explanation.

The JAM detection method will be specifically explained with reference to FIG. B
For size 5 (Figure 18-1), first the document table reaches the home position at 5TEP30, then proceed to the routine shown in Figure 12 (■), the clock counts 5, and S TEP
In step 4.5, it is determined whether the transfer paper is on the paper detector 180, and if it is not (one sheet has stayed), then in 5TEP 48, it counts another 4 clocks and determines whether the transfer paper has reached the paper detector 180 or not. . Note that when the signal has been reached, the signal from the Hall element 129 is at 0 level as shown in FIG. 23(C). (Transfer paper delay) If the paper arrives at the paper detector 180, it indicates that the transfer paper is being fed normally.

On the other hand, regarding B4 size, it is as shown in Figure 18-2 (
(mentioned above). If this operation is shown in a time chart, No. 18-3
It will look like the figure. Therefore, the B5 size uses a clock, and the B4 size uses the B4 inversion position signal and stop position signal. In this way, since jam detection is performed by selectively using the clock and the signal on the document table depending on the paper size, it is possible to conveniently perform discrimination control even when the jam discrimination and load operation are similar. Furthermore, as shown in FIG. 18-3 (C), when a large number of sheets are to be continuously copied in B5, the delay is determined by B5BP, and only the last copy is based on the clock.

Moreover, in this example, B5. In A4 size, a clock is used to detect JAM, but it is possible to use a clock φ for the drive of a microcomputer as mentioned above, which is divided in frequency,
An external low frequency oscillator can be used.

In this embodiment, the method for disabling these JAM detection operations is to short-circuit the CPI (JAMK) in Figure 8 to ground, but it is also possible to control the number of copies etc. electrically from the outside. This can be done using the numeric keypad. In other words, J
Code the long sword signal for AM kill, ignore the discrimination of the liquid kill signal LEP), ignore the discrimination of the paper kill, JAM kill, liquid kill, and paper kill signal PEP), and input the data using the numeric keypad ( Figure 11 (before 5TEP4), R
A flag is set at a specific address in the AM area, and a step is provided in advance during the program to jump to this step immediately before the jam detection, liquid, and paper side steps, and when the program is executed at this step, The corresponding killing data storage addresses of It and AM are read out to determine whether the flag is 1 or 0. When the flag is 0, the program proceeds to each determination step, and when it is 1, the program jumps the determination step and proceeds to the next sequence step.

Further, in the present invention, rs5. To automatically return the original platen to the longest paper size even if the magnetic detection element for A4 or the like is damaged. If the magnetic detection element that detects the document platen reversal signal for the longest paper size is damaged, the document platen advance motor may be overloaded because there is no reversal input.

When the document table moves forward, the time from when the document table advances to the reverse position of the document table for the longest paper size is fixed, regardless of the paper size, so set the timer for this fixed time.
Make by counting P. Therefore, as described above, the paper size flag is stored in memory, so if a predetermined reversal signal (at the time when predetermined CI and KP are counted) is not output for a predetermined paper size, the document table is automatically reversed. This timer counts the aforementioned CLKP, uses an external low frequency generator, or uses a frequency obtained by dividing the microcomputer drive clock φ.

Table 2 is an example showing the flow of FIGS. 11 and 12 in program code, and the command words are omitted because they are clear in the TMS 1000 user's manual.

Next, the power supply circuit shown in FIG. 22 which supplies the microprocessor will be explained. This circuit consists of a 15V stabilized power supply circuit and a 15V shutoff circuit.

In this copying machine, even if the main switch is turned off during the post-processing after the copying operation is finished, the post-processing is executed to the end and then the drum rotation and load energization are stopped. A control step is provided to issue a power hold signal. This copying machine includes a power transformer for supplying DC to the control circuit and other DC loads. A 24V rectifier circuit is used on the secondary side of this power transformer, but a very large capacitor (for example, 2200 μF) is inserted in the smoothing circuit of this rectifier circuit. -In case there is a line where AClooV is supplied by the main switch as an ON/OFF river for this power transformer, on the primary side,
ACloo even if the main switch is turned off during post-processing
There is a line to which V is supplied.

Even if the main switch is turned off during post-processing, the AC
The signal that drives this circuit so that looV is supplied is the aforementioned power bold PT-IT,D signal.

The cleaning blade can be removed from the drum by turning off the PH-LD, and then brought into contact with the drum by turning on the power.

If the main switch is turned OFF during post-processing and the power hold signal is output and the power hold signal becomes OI'i', 1" after post-processing, the primary side of the power transformer will be OFF and the secondary side of the power transformer will be rectified. The circuit is also O
Becomes FF. However, because the capacity of the smoothing capacitor in the smoothing circuit is large, the discharge time is long (about several hundred m5
ec).

Moreover, there is plenty of room in the operating range of the microcomputer's power supply voltage. Therefore, if the power supply voltage waveform falls in a gentle curve around the voltage at which the microcomputer starts to malfunction, the microcomputer's R, A
M, ROM, etc. begin to malfunction. At this time R, AM, R
If a power hold signal is issued due to an erroneous output from the OM, the AC 100V line mentioned above will become active again even though the main switch has been turned off and the rotation has ended.

In this case, of course, the other R and AM areas of the microcomputer also have incorrect values, which may cause display lamps such as the JAM display lamp to light up, thereby adversely affecting operation.

FIG. 22 shows a shutoff circuit that eliminates this drawback. In the figure, 601 is a resistor for flowing Chener current, 602 is a 20V Chener diode, 605 is an NPN transistor, 604 is a transistor collector resistor, and 607 is an NPN transistor.
]]N) transistor, 606 is transistor collector resistance, 608 is voltage drop resistor, 611 is ], 6
V Zener diode, 610 is silicon diode 6
09 is a control transistor.

To explain the operation, a resistor 608, a transistor 609,
The circuit constituted by the Zener diode 611 is a well-known constant voltage circuit, so its explanation will be omitted. The Chena voltage of the Chena diode 602 is about 20V, and the base current is supplied to the transistor 605 through the resistor 601. If +24V is currently input to this circuit (the input is connected to a circuit that smoothes the transformer output, and the 15V output is connected to the computer power supply terminal), that is, while post-processing is being executed, a Chena current flows through the Chena diode 602. The transistor 605 is in a conductive state, current flows through the resistor 604, and the collector of the transistor is at almost zero potential. On the other hand, through the resistor 604, l.
Since no base current is supplied to the base of transistor 607, transistor 607 is in a non-conducting state. Therefore, only the Chena current supplied to the resistor 611 flows through the resistor 606, a Chena voltage of 16V is maintained across both ends of the Chena diode 612, and a constant voltage of 15V is supplied to the output. However, as mentioned above, after the post-processing is completed,
A power hold signal is output from the control circuit, and the +24V power supply gradually decreases.

When the +24■ voltage becomes around 20V, the Zener diode 602 becomes non-conductive, the transistor 605 becomes non-conductive, and the transistor 607 becomes conductive, and the collector of the transistor 607 becomes approximately 0■ potential, and the 61
No Chena current flows through 1, and the output voltage becomes 0.

At this instant, the diode 610 is connected to the transistor 609.
It is included to block reverse voltage applied between the 0 base and emitter.

In this way, when the +24V voltage becomes around +20V, the power supply to the load is forcibly stopped.

Therefore, even if the discharge time constant of the smoothing circuit is extremely large, it is effective for control circuits having memory circuits.

Table 2 OPT LTST, Xl1l[Brl LBDDDDPA
GE O MNEZ Lr3CCCBL LBGGGBRLBA/
l 1. I]D[)D TCY 4DYN TCMIY
3 MAN TAN LDIIIIII CAI, LL 5UBSI
ZENEZ BRLBBB CALLL 5UBLPYN DMAN GALLL SIIBCCMDTAM MN
EZ MNEZ BRLB997 BRLBCC[]RLIl19913 LB! ]97 BL L[134 BL LBDD LBAA IYCLB9! ] [l CALL 5UB
CBRVBL LB5 CALL 5UrlCNTL
BBB IYCTOY 4 MAN BL LB4 TAN LBCCIYCMNEZ BRLBIIIH BL LB3 LBAAA CALLL 5UBCNT 131. L
BBBBTCY 4 PAGE I DMAN TC:Y 2 TAM SETR MNEZ TKA BRLBCCCR3TR TCY OLB300 ' TCY 3TAM TcM
IY 4 TBITII LBX TCY 15 BRLBA TCMIY O BROTCY 3 ETN LBA BL LB25 LB301 TCY 2SU
BSIZE BRLBB 5ETRLBC5ETRTK
A TKA R9TR R9TRTCY 0 TCY OTAM TAM TBITI 3 TBITI 2 BRLB303 BRLB301 TCY 3 THEY 2 TCMIY2 SETRBRt, Bx TKA LB303 TCY 3 R9TRTCMI Y I TCY OBRLBX TAM LBB CLA TBITI'3 TCY 3 BRLB300 TAN TCY I TOY 2 SBIT I BRLBC TMA PAGE 2 TDO5UBPDPI TCY I TCY 3 5ETR TC:MIY OTKA TCY 15 RSTR TCMIYI TOY 0 TCY 3 TAM RETN TBITI 3 SRSUBJAM CALLL SUI'1GBRVL
BD RETN 'l°KA LB? OQ CALL StlBJAMSIIBPDP
2 BRLBCQ 13L LI]901LBCJ 5
ETRL[]CQ TGY 12TKA T131Tl
3 R5TRBRLBI] TCY OTGY I TAM IIR1, BCJ TBITI3 La7O9TCY I BRLBD 5ETR BRSUBJAM TKA SUBJAM Ti1l:Y I R5TR5BIT
3 Tll;Y O TMA TAN TDO7BIT11 TCY IQ I]RLn50EI SETRTCY 5 LB8QODYN 5ETR RSTRDI? SUOJAM YNEC: 8 L[350fl TOY 5BRLa
8O0R5TR TOY 4 13RSIIIJAM LBi300 R5TRPAGE 3 DYN 5IInCNT Tl(A YNEC: OT(:Y Q BRLa9O07AN BRLa7O9TDITI 0 0R5tlBCNT LBINTI CAL LL 5UBSIZE Ln2O
3TKATCY 0 CALL 5tlBLP TAN TBITI O 7 BRLBE TAM BRLn2O3TBITI 2 StlBTSSD TOY I BRLBESETRL
Bf(00TC:Y 14 TKA MNEZ R3TRBRLB801 TCY ORETN TAN La6O1TCY I TBITI 2 5BIT O BRLBLLL TMA BRLBE TDO LBLLL TCY 14 TCY OTCMIY O
R9TR RETN LBE RETN SUBTSL TCY I PAGE 4SETRSL
IBCCMD TCY 0TKA 5ETR R3TRTKA TCY O, RSTR TAM TAM TBITI 2 TBITI 3 BRLa5O0SRl, B4O1 TCY 14 La4O0TCY 2 TCMIY I TCMIY 0 RETN BR LBF LB500 TCY 14 La4O1TCY ITC
MIY OTMA RETN ALECl 5LIB setting TCY 1' BRLa4O2SETRB
RLa4O0 TKA La4O2TCY 2 R5TRTCMIY I TCYOLBF DYN 8 RETN CAI, Ll, 5UBLPLB45 TC
Y 2 SETRCALL 5UOCBRV TKATK8R9TRTC'/ O TC:Y OTAM TAN TBITI 0 TBIT11 BRLBCK SRLBKTomoguchi RLBINT2 BRLBNNN L13CK BL LBRLP LBMMM BL LB4B LI3RI000 BL LBINTI LBNNN BL LB47 PAGE 5LOP T
C:Y 2 TCY 11 SETROM8 TKA TAN R3TRMNEZ TC:Y OBRLBJ TAN BRLBK LB998 TBITI I BRLa9O9LBK GALLSUB BL LB
FFF BL LB100OLB999L [lP 12
5UIICnRV TCY IBRO5ETR LB! 1101 DINGCY OTK Hachie AM R3TR 3BITIOTCY O BRLa9O00TAM TBITl 1 LBINT2 CALLL 5UI3SIZE ORL
BlooTCY 5 SETRRBIT I RETN TMA LBloo TCY 5 TDO R3TRLa2O3RETN ETN SUBLP Ti1l:Y OLBJ BL LB51
SETRPAGE EI KA R3TRLB4B (1: At, L 5UBTSSII
TCY 0 TAN BL LB45 TBIT12 LB47 TCY 2 BRLa2O05ETR T(1:Y I TKA SBIT 2 R3TR TMA TCY 0 TDOTAN BRLa2O2TBITI I LB200 TOY I BRLB4 8MA TDOCALL 5UBTSSD TCY 15 BRLB47 NEZ BRLBJJJ LB48 CALLLSUBTSLL
B201 TCY OTCY 8 TBITI I 5ETR BRLa2O2TOY 4 LBJJJ TCY I R3TR 3BIT I TCY 5 TMA 5ETR DO BRLa2O3CALLL 5IJBPOPILB20
2 TC:Y I LB4!3 TCY 15ETRL
B40 CA1. LL 5IIBPDP2TKA TC
Y 11 R3TRTCMIY 7 TCY O TAM LB41 CA1. LL SII[ICNTT
BITI 1 1'CY 11 BRLB50 nM 8 to AN CALL 5UBTSSrl BRLB49 C to 1 L 5UISIZELB50
TCY 5 R3TRCA1. I, L 5Un1. PCALL 5
UBPDP2 CA1. LL SUI3CGMDTOY
11 8NEZ TCMIY? 13RLIIIM nRL[]0 LB51 CALLSUBSIZE LBOTCY
I+HN[Z CALL 5UBLP nl1i LD42CALL
L SUBCCMD CA and LL SUL'1TIEL
NEZ BRLBL []LL LBlooO CALLL 5UBCNT LB42 CALI 几 5
IIrlClIRVCALL 5UBTSSD CA
LLI, S strikeTSSDLDP 5 rlRLn41 BROLf343 TCY 8 5TR LBL BL LB]f(Tr:Y IIPAGE?
5ETR 1 TCY 6 DMAN 5ETP TAM TOY 5 BRLB34 STR DMAN LB36 CALLL SUBPDPITA
M TCY 4 MNEZ TCMIY 4 BRLB44 LB37 CALL 5UBTSSD CALL 5
UBPDP2 CALL 5UBCNT BL LBP TCY 4 MAN LB44 CALL 5UBTSSD TANBRL
B43 MNEZ LBM BL LB16 BRLB37PAGE 8 LB34 TCY EI CALLSUBPDP2E
TR TCY 5 BL LBP R3TRLB38 TCY B TCY 8 5ETR R3TRTCY 8 TCY 4 R5TR 3ETRTCY 5 MNEZ R9TR BRLB35 TCY 4 BRLB36 5ETR NEZ LB35C ALLSUBCNT BRLB39BL
LBP CALL 5UBTSSD TCY 4 LB3!11 CALLLStlBCNT
2 CALL 5UBTSSD TAN TCY 4 MNljZ DMAN FIRLB33 AM BRLB38 1'lL tB40 PAGE 9 TCY5 LB33 CALLL 5UBTSSDMA
N TAM CAIIL SUBCBRV MNEZ BRLB32 BRLB30 LB2000 TCY 4NEZ CALL 5UBPDP2 [IRLBSIIRLB
T BL LBP LIFT CAshi LL SUI] PDP2LB30 C
ALL 5UBTSSDCALL SO3 BL LB29 LB31 TCY 5 []LL LBlooOTCM
IY 4 LBZ MNEZ []111 LBU LB32 CALL 5UBCNT BRLBVCA
LLL 5UBSIZE Lr1U nL LB12C
ALLSUBLP LBV [ll LBIOLBI
TOY + CALLSUBCCMD IIIBIT +TCY
3 BL LBXORETN LBRTCY 5 DMAN LBQ nL LB43 73 -m- LBS BL LB23 LBKKK TCY IPA
GE 10 5ETR LB24 TCY 2 ' TKA SETRR3TR TKA TCY 0 R3TRTAM TC:Y OTBITII TAM BRLB27 TBITI I BRLBKKK BRLB24 LB27 TCY 5 BRLBW R5T R 3ETRCALL 5UBSIZE CALL 5
UBSIZETBITI I BRLBY CALL 5UBLP BL LB45 CALL 5UBCC:MDNEZ LBY CALLSUBTSL, BRLB28LB
26 TCY 5 SETRBL LB31 TOY 8 LB28 TCY 5 SETP TCMIY 4 TC:Y 4 R3TRLB29 CALLL 5UBCNTTCY
4 CALI,L 5UBCNT 5ETRTCY 8 CALLL 5UBCNT R3TR LDP 9 CALLL 5UBCNT BR0 LBW LDP] CALLL 5UBPDPI BR0 4 PAGE II CALLLSIInl, PCALL L
5UBPDPI CALL SUBCCMDLB2
0 TGY 2 MNEZ SETR [IRLB995 TKA IIRLB994 5TR TCY 0 1, B2S3 BL LB38AM TBITI I LI]094 GALLL 5UBC
BRVBRLB21 CALL 5UBTSSD B1. LB2000B
RLB20 LBXO)INEZ 13RLBCY LB21 CALLSUBPDP2 BRLIICZ
BL LBOOOLBCY [11, LB29LB22
BL LBAAA LBCZ BL L13RPAG
E 12 LBBBB CALL 5UBPDPITCY 4
CALL 5till] SIZETCMIY 4 T
BITI O BRLBI7 LB23 CALLSUBTSSD [']L LB
24CALL 5UBCNT L1117 CALL
L S TSLTCY 4 L[3111TCY 4 OMAN R8TR TAN TOY 5 ETR CALL 5UBSIZE TOY 8ETR 5 TC:Y I LBEEE CALLSUBCNTS
ETRTCY 8 TKA 5ETR R5TRCALL 5UBTSSD TCY OTCY 5 TAN R3TR TBITII TOY 8 BRLBI8 R5TR TC:Y 4 CALLL 5UBTSSD 5ETRBRLBIII
DMAN LB18 TC:Y 5 TAIII R9TRMNEZ TOY 4 BRLBEEE TCMIY 2 LDP I+ R0 LBGGG CALLSUBTSS[l PAGE
13LBIOTCY 3 CALLL 5UBSIZE RSTRTCY 4 CALLL 5UBLP RSTR TCY 1O CALLL SUBCCMD LBII R3TRMN
EZ DYN BRLBI9 YNEfll: 5 BRLBII BL LB22 LBI9 TCY 4 CALL SUBC: BRVM
AC rA CALL 5UBSIZE A TAN CALL 5UBLP 6 CALLSUBCCMD ' TOY (IIETR BL LBZ TOY 8 LB12 TCY 11 SETR TCMIY9 Ti1l:Y 5 LB13 TC Y 3 R9TR ETR TCY 7 BL LBP LB14 9ETR IYCLBOOOLOL LBIO YNEo 10 PAGE 14 BRLBI4 TCY 11 TCMIY [I CALL 5UBCNT LBB CALL 5UIICBRVCALL 5
UBCBRV C to I, CL 5UBSIZE CALL 5UBSIZE CALL 5UBLP CALL 5UBLP C^1 L sunccM.

CALL SUBCCMD MNEZMNEZ I]
RI, Rolo85 BRLBI5 RoRL mouth 984 BL LBlooOLB985DL LB12LB15
TOY 10 0MAN LBB[14CALL 5IIl]GNT
TAM TOY II MNEZ DMAN BRLBI3 TAN LB18 TCY 4 MNEZ SETR[]RL port 8 LB100OTCY 7 BRLB3000R3TRT
GY 13 TOY 13 DMAN TC:MIY 2 TAM TOY 6 MNEZ R9TRSRLB5000 LB5000 TCY 11 TCMIY OBL LBOOO LB3000 TC:Y 9 PAGE 15R3TR
LDP 15 TCY 10 LDX 0 5ETRTC:Y 10 LBI R9TR CALL 5UBC:BRV TCMIY OYN CALL 5UBSIZE DYN BRLBI CALLL 5UBLP CLO TCY 9 CALLL S UBCCMD SETRMNEZ TC
Y? BRLBII93 LB3 TCMIYIOBRLB9
92 LB4 TCMIY15LB8i33 TCY
10 LB5 TC: MIY15R5TRTCMIY
15 BL LBI2 CALL 5UBCBRVTC:Y
12 LB882 CALLL 5UBCNT TKATCY
11 TAN I) MAN TCY 10 TAN LBB DMAN MNEZ TAN MNEZ BL LB16 BRLBEI END YN MAN AM LDP O BR0 LBDD TOY 11 TCMIY 10 TC:Y 3 ETR TCY? ETR TC:Y 8 ETR TCY 8 5TR LB7 BL LBINTI LBRLP CALLL 5UBCBRVCALLL
5UBSIZE CALL 5UBLP TCY I+ MAN AN MNEZ BRLB7 LDP 14 BR0 LBFFF CALLL 5UBTSSD9

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an example of a copying machine according to the present invention, FIG. 2 is a vertical sectional view of FIG. 1, FIG. 3 is a first cross-sectional view, and FIG. Figure 5 is a perspective view of the cassette, Figure 6 is a control circuit diagram, Figure 7 is a block diagram of the microcomputer, Figure 8 is a RAM area diagram, Figure 9 is a basic time chart of the microcomputer, and Figure 9 is a basic time chart of the microcomputer. Figure 10 is a system flowchart of the operation of the copying machine in Figure 1, Figures 11 and 12 are detailed flowcharts of Figure 10, Figure 13 is an operation timing chart for B5 size, and Figure 14 is an operation timing chart for B4 size. , 15th
The figure is an input matrix circuit diagram, Figure 16 is an output control circuit diagram, Figure 17 is a clock level control flowchart, 0 level control flowchart, Figure 18-1 is a jam detection flowchart for B5 size, and Figure 18-2 is a B4 size 18-3 is a jam detection flowchart, FIG. 18-3 is a jam detection timing chart, FIG. 19-1 is an ATR flowchart, FIG. 19-2 is an ATRITQ path, and FIG. 20 is a clock generation diagram. Figure f121-1 shows the measurement circuit when left unused, the second
Figure 1-2 is the operation time chart of Figure 21-1 and Figure 22.
The figure shows a power supply circuit, and FIG. 23 shows a circuit example of the input sensor shown in FIG. 6, including 11, I2, 14. IB is an input terminal to the computer, 01 to 015 are output terminals to the computer, A4BP, B4BP, B511P are document platen reversal position signals, MSI, MS2 are cassette size signals, DDP
is a paper inspection 111 signal, TSC is a toner concentration signal, and TSE is a toner replenishment possible signal. Applicant Canon Co., Ltd. No./θni No. // Wa ■■■ JP-A-Sho GO-95452 (27) B5 (a) (b) 5 Revised introduction 3! ! Ren VAN JAM (C) (? > Ml/ITI ((1) (b) (C) No. ?/-7 Figure ?/-? Figure ≦ Lluhi W) 111 m-through procedural amendment to AI' (auto) ) 1. Indication of the case 1982 Patent Application No. '112861 2 Name of the invention Image forming device 3 Person making the amendment Relationship to the case Patent applicant's office 3-30 Shimomaruko, 1.11-ku, Tokyo Metropolitan University -2 name
(100) Canon Co., Ltd. Representative Ryu Kaku 3rd Department 5, Application subject to amendment and specification 6, Contents of amendment (1) The application is amended as per the attached sheet. (2) Delete aA Thin Tube, page 4, line 8 to page 5, line 10. (3) Correct "Paper feed" in the 11th line of page 5 to "Paper feed in the above device." (4) "Subject" on page 5, line 12 of the same page is replaced with "copying material or"
Correct to. (5) Delete page 6, line 3 to page 11, line 9. Procedural amendment (buwi) November 29, 1980 Patent Application No. 112881 2, Name of the invention Image forming device 3, Relationship with the person making the amendment Patent applicant address 3 Shimomaruko, Ota-ku, Tokyo -30-2 Name (100
)Representative of Canon Co., Ltd.Karai 3rd Department 46Representative Address 3-30-25 Shimomaruko, Ota-ku, Tokyo 146, Daily publication of the amendment order October 30, 1980 (shipped ``1 visit'') 6, Subject of amendment Write specifications and drawings. (Contents 1τ and φ are not included.)

Claims (1)

[Scope of Claims] Processing means for forming an image on a sheet, means for detecting a sheet provided on a sheet travel path, means for generating a mode signal to select a mode of image formation, and means for detecting a jam. a plurality of timing signal generating means, one of the plurality of timing signals according to the mode signal;
an image forming apparatus comprising means for determining one. TS” detailed engraving (no changes to the content)