JPS6252293B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to an image forming apparatus that forms an image on a recording material according to a predetermined sequence. [Prior Art] In order to prevent copying errors due to erroneous operations, the applicant proposed prohibiting the input of command signals using keys necessary for copying operations during and before the completion of image formation (Japanese Patent Application No. 1987- No. 143178). However, enabling key input only after image formation is completed and the image forming process means has stopped is a problem for operators who wish to continue operation, especially after the completion of the image forming process. This was inconvenient for long equipment as it required a long wait. [Problems to be Solved by the Invention] However, if key input is enabled before the image forming process means stops, and preparation or start operation for the next image forming operation is enabled, problems associated with image forming that is still in progress. This causes an inconvenience in that the next image forming operation is executed even though there is an abnormality in the conveyance of the recording material. [Means for Solving the Problems] The present invention has been made in view of the above points, and it forms a latent image on a rotating body and prints an image corresponding to the formed latent image on a recording material being conveyed. A program memory storing a process means for forming, an input means for inputting a command to start image formation, a program for sequentially controlling the above-mentioned process means, and a program for monitoring abnormal conveyance of the recording material, and image forming. and a data memory capable of storing data related to the recording material, and controls the process means to execute image formation according to the data stored in the data memory according to the program stored in the program memory, and and control means for monitoring abnormal conveyance, and the control means is capable of receiving a start command by the input means during the subsequent rotation of the rotating body before the completion of a series of image forming operations, and when the start command is When the start command is input, data indicating the input of the start command is set in the first area of the data memory, and it is determined whether or not the data is set in the first area of the data memory after abnormal conveyance of the recording material is determined. If abnormal conveyance of the recording material is not detected, the image forming operation is terminated if the data is not set in the first area of the data memory, and the data is set in the first area of the data memory. If so, the image forming operation according to the numerical data set in the second area of the data memory is started without any further start command from the input means, and on the other hand, abnormal conveyance of the recording material is detected. In such a case, the present invention provides an image forming apparatus that executes abnormality processing and prevents the start of a new image forming operation even if data is set in the first area of the data memory. [Embodiment] Hereinafter, an embodiment of the present invention will be described in detail regarding an example in which a one-chip microcomputer (hereinafter referred to as CPU) is used to control various functions of a copying machine. Regarding this embodiment, 1. Outline of the copying machine 2. Operation display section 3. Control circuit, control load 4. Computer and peripheral circuits 5. Explanation of the flag and initial sequence flowchart 6. Explanation of the flowchart of the half-size sequence 7. Flow of the full-size sequence The explanation will be given in the order of the chart explanation. 1 Overview of Copying Machine The operation of a copying machine which is an embodiment of the present invention will be explained with reference to FIG. The original is placed on the original table which constitutes the original placing surface, and is pressed down by the original pressure plate 10.The optical system includes an illumination unit 101 consisting of an illumination lamp 9, a movable reflection mirror 8, a movable reflection mirror 6, a lens 17, and a fixed It is composed of reflecting mirrors 18 and 19. Therefore, the original is moved by the movable reflecting mirror 8 which moves in the direction shown by arrow A in the figure together with the illumination lamp 9, and by the movable reflecting mirror which moves in the same direction at half the moving speed of this movable reflecting mirror 8. 6, while the optical path length is kept equal, the light is exposed to a slit through a lens 17 and fixed reflection mirrors 18, 19, and is imaged onto a drum 30 having a photoreceptor on its surface. That is, the document is exposed to slit light while being scanned by an optical system (illumination section). The surface of the drum 30 has a photoreceptor whose photoreceptor layer is covered with a transparent insulating layer. Becomes electrically charged. Subsequently, when reaching the exposure section 16, the original on the original platen glass is illuminated by the illumination lamp 9, and an image is formed on the drum 30 by a moving reflection mirror, a lens, and a fixed reflection mirror, so that the photoreceptor is exposed to the original image. At the same time, AC static electricity is removed by the AC discharger 13 to which AC high voltage current is supplied from the high voltage power supply. Next, an electrostatic latent image is formed on the surface of the drum (photoreceptor) by being exposed to light by a full-surface exposure lamp 33, and then enters the developing device 31. Development is performed by powder development using a sleeve method, and the electrostatic latent image is visualized. Next, the transfer material is fed from the cassette 21 or 22 by the paper feed roller 24, and the first roller 25,
The paper is conveyed by the second roller 28, temporarily stopped by the timing roller 29, rotated by the registration signal, and conveyed again. The registration signal is obtained from a switch RG that detects a specific passing position of the optical system. The switch OHP generates a signal indicating the optical system home position (stop position). This fed and conveyed transfer material comes into close contact with the drum, and the image on the drum is transferred onto the copy material by a transfer charger 27 using a positive high-voltage current from a high-voltage power source. After the copying material has been transferred, it is separated from the drum by a separation roller 26, guided to a heat fixing roller 4, and after being fixed, excess charge is removed by a static eliminator 3, and the material is ejected onto a tray 20 by an ejection roller. Ru. Copying is now complete, and the remaining toner on the drum is cleaned by the blade 11 pressed against the drum surface (photoreceptor), allowing the next cycle to be repeated. To avoid complexity, a detailed explanation of the drive system and the sequence and timing of each process will be provided later.
A cam installed on the drum operates switch PF to generate a paper feed signal. The switch DHP generates a drum home position signal and stops the drum at the position where the photoreceptor joint contacts the cleaner 11. Reference numerals 23a and 23b denote a lamp for detecting the presence or absence of paper in the cassette, and a light receiving element that receives the light. Reference numeral 2 denotes a paper detection lamp and a light receiving element for detecting paper delay and retention therein. Reference numeral 16 is a blank exposure lamp which exposes the photoreceptor to light to eliminate surface potential unevenness when imagewise exposure is not performed. 7 is a fixing motor, 15 is an optical motor,
A pre-exposure lamp 14 is used to fatigue the photoreceptor and make it uniform before the process. Further, 36 is a pulse generator composed of a plate that rotates in conjunction with the drum and an optical detector that detects holes in the plate. 2 Operation display section The operation panel of this device is shown in Fig. 2. The operator can interact with the CPU via this control section. That is, the key groups 21, 22,
The CPU is displayed on displays 24 to 28 for input 23.
indicates a response. The operator can set the desired number of copies up to 99 on the display 25 by pressing the numerical keys 0 to 9. The "CLEAR" key is used to clear the set contents of the display 25 to zero. The “MULTI” key is on this display 2.
Used when you want to copy only the desired value shown in 5. Once this key is pressed, the machine enters the copying operation and when the optical system reaches the reversal position,
The value on the display 26 is incremented from 0 to +1. Then, when the set value on the display 25 matches the value on the display 26 indicating the number of copies copied, the copy operation mode changes to the end mode, and when the copy operation ends and the photosensitive drum stops, the display 26 shows the number of copies. is returned to “0”. Therefore, the value initially set using the numeric keypad still remains on the display 25, so if you want to make the same number of copies of another document, you can press the "MULTi" key again. However, this "MULTi" key is
When the value is "0" and any one of the display groups 24 is lit, it is ignored. During “MULTi” copy operation, when the copy count number does not reach the set count number,
When the “STOP” key is pressed or display group 2
When any one of 4 lights up, the copy operation at that point is ended, and the copy cycle is ended. Therefore, for example, if the above state occurs when the set count is "6" and the copy count is "3", the display 25 is at "6" and the display 26 is at "3" and stationary. At this time, key group 2
2 accepts all. Further, after the copy operation is completed, all of the key groups 21 and 22 are accepted. The "SINGLE" key performs a single copy operation regardless of the set count or copy count. Therefore, using this key, interrupt copying is possible only for copying a single sheet. For example, when the first operator sets six sheets on the display 25 and the copy count reaches three, the second operator requests to interrupt the copying of one sheet, the first operator presses the "STOP" button. The second operator presses the button to finish copying once the three sheets have been copied, and the second operator sets his own original and presses the "SiNGLE" key. The display 25 shows "6" and the display 26 shows "6". 3", one sheet copying for the second operator is completed. Therefore, the first operator can make the remaining three copies by pressing the "MULTi" key again. If the desired number of copies is not one but a plurality of copies, this can be done using the "INTERUPT" and "RECALL" keys. Said above, when the first operator stops the printing in response to the second operator's interruption with the set count "6" and the copy count "3", the second operator prints two sheets.
To interrupt the copy, the second operator presses the "INTERUPT" key, temporarily saves the set count number "6" and the copy count number "3" to another memory, and lights up the interrupt lamp 28. After that, press “2” using the numeric keypad.
Enter as the set count number and press “MULTi”
Press the key to complete the two copy process. After this, press the "RECALL" key and the numbers for the first operator, "6" and "3" will appear on the displays 25 and 2.
6, the first operator can press the "MULTi" key again to make the remaining three copies. The display lamp 27 "ORIGINAL" indicates that the original can be set or replaced, and goes out during copying. Therefore, since the light turns on when optical scanning of the last paper copy is completed, copying can be started again by immediately replacing the original and pressing the "MULTI" or "SINGLE" key. The indicator lamp 28 “INTERUPT” lights up when you press the “INTERUPT” key.
It disappears when you press the “RECALL” key. "JAM" lights up immediately when a copy paper jam occurs, and puts the copy in end mode. At this time, the display 26 shows the CPU depending on the location where the paper jam occurred and the paper size.
-1 or -2 and ends the copy. In addition, when jamming occurs, the operator opens the door of the device and removes the jammed paper, so the total counter that calculates the copying fee only counts after the paper is stored in the tray, and jammed paper is not counted. . In other words, both the copy count display and the total counter are guaranteed to count during a jam. The "TONER SUPPLY" display lights up when the toner in the developer unit runs out, and does not affect the start or continuation of copying. "PAPER-SUPPLY" lights up when there is no more paper in the selected cassette, prohibiting the start of copying or terminating continued copying.
"WAIT" is turned on for a period of time until the temperature of the fixing device reaches a desired value and prohibits the start of copying, but once that temperature is reached, the start of copying is enabled and the enabled state is maintained. Switch button “UPPER-CaSSETTE”,
“LOWER-CASSETTE” is the upper part of the cassette,
When the lower row is selected, the lamp group 25 displays the paper size stored in the selected cassette. If you press the push button switch "AUTO", when there is no paper left in the selected cassette, the paper will be automatically pulled out from the selected cassette and the copy will be made only when there is paper of the same size stored in another cassette. You can continue. 3. Control circuit, control load Figure 6-1 shows a control circuit that inputs and outputs to the computer, and Figure 6-2 shows peripheral circuits for input and output. In the figure, the CPU is a memory that stores the control program shown in Figure 5 (described later), a memory for saving the operation timing numerical data necessary for program execution, a count value save for copying interrupts, input data, and a logic for decoding the above program. It is a computer chip device whose circuit is included in one semiconductor substrate. The details are shown in FIG. Outputs a to d are connected to a display device via a segment decoder 608 in order to display the number of sheets on the display devices 25 and 26. The output CT is used for column scanning of the input matrix circuit and digit scanning of the displays 25 and 26. The gate circuit has a so-called decoder function, which is used to combine signals from the chip outputs to obtain more output signals. This gate circuit provides the output of the CPU to the input matrix circuit and output interface circuit. 603,604
is an AND gate, 601, 602, and 606 are inverters, 605 is a NAND gate, 607 is an OR gate, and 609 is a paper detection circuit using a transistor. Each digit of the display is displayed using 7 segments, and the digit is selected by the output CT signal from the chip. This is a number 1 that is issued alternately in the order of each CT.
A segment of the required number of digits is selected from the 10,000 outputs and the 4-bit outputs a to d output simultaneously.
Dynamic display that alternates display units in sequence. Inputs from input switches crossing the outputs CT _1-1 , CT _1-2 , CT _2-1 , and CT _2-2 are similarly dynamically input. As will be described later, the present invention has a feature that it can be displayed even during process execution, and input can be made even before the process is completed. The scanning output signal for inputting key entries etc. is output sequentially by the clock for computer program processing, while the output for operating the control load is an output of the length required for the load to be turned off. There is also a driver circuit (not shown) which serves as an interface circuit and powers up a signal from the gate circuit to drive a solenoid, lamp, etc. An AC load or the like is driven by ANDing with the output from the oscillator and outputting it as a trigger signal for a triack or the like. In the matrix circuit section, a matrix is constructed such that the scanning line and the input line of the microprocessor intersect, and the point at which this intersection becomes a switch corresponds to the input command section. x scanning lines and y input lines of the processor
In the case of a book, a maximum of x and y switches are possible. The ROM included in the computer chip element has a master program for executing the sequence of the copying machine arranged in advance and embedded in each address, and has a readout function that allows the contents to be retrieved each time a specific address is set. With dedicated memory
It is a well-known matrix circuit that is set in advance with a code from address 0 to the final address required.
Store programs (key entry programs, equipment operation programs, machine termination programs, etc.) in binary codes. RAM is a read/write memory that stores the number of copies and temporary control signals during process control, and is a well-known memory that stores one set of binary codes, and is composed of multiple sets of flip-flops. However, an arbitrary set is selected by the address designation signal, and data is written to or read from a plurality of flip-flops within the set. [About control timing and control load] Figure 3 shows the control timing chart and control load for half sizes such as A4, B5, and U2, and Figure 4 shows the control timing chart and control load for full sizes such as A3, B4, and U1. . U ₁ and U ₂ are universal cassettes, and U ₁ stores paper of any size corresponding to the full size of U ₂ . The SW is a switch that turns on the power to the device and lights up the power-on indicator lamp at the same time. M1 is a motor for rotating the fixing roller, _L1 is a wait lamp that indicates copying is possible, _H1 and _H2 are fixing heaters built into the fixing roller, and cooling blower _M2 is a motor that cools the above heater, the main The motor rotates the photosensitive drum, the paper feed roller PL is a plunger that lowers the constantly rotating paper feed roller 24,
The first register PL is a plunger for driving the first roller 25, the second register PL is a plunger for driving the timing roller 29, the developer PL is a plunger for driving a screw that stirs the developer powder, and the ATR detection is a plunger for driving the screw that stirs the developer powder. An optical detector is used to detect the drop, and the Hoppa HOP uses the toner replenisher and pre-exposure lamp that are activated by the detector.
L ₂ is a lamp that uniformly irradiates the photoreceptor in advance, optical motor M ₄ -F is a forward motor that moves the optical system to expose the document, and optical motor M ₄ -B is a motor that moves the optical system backward. Motor, exposure lamp
L ₃ is a lamp that illuminates the photoconductor with the original image, blank exposure lamp L ₄ is a lamp that uniformly exposes the photoconductor when the document is not exposed, and L ₅ is a lamp that uniformly exposes the photoconductor during the entire surface exposure process. , the primary transformer Tr ₁ is a primary charging transformer, and the bias transformer Tr ₂ is a transfer charging transformer. Details of these operation timings will be described later. In these control loads, the main motor,
Cooling motor, AC charger transformer Tr ₃ for static elimination
operation control signal for the upper paper feed roller plunger PL of the cassette, control signal for the optical system forward motor _M4 -F, exposure lamp _L3 , developer plunger PL, optical system backward motor M4- _F .
B control signal, pre-exposure lamp _L2 control signal, jam indicator lamp, reset plunger control signal, AC transformer voltage switching control signal, primary transformer _Tr1 , bias transformer
Control signals for Tr ₂ and blank exposure lamp L ₄ are output directly from the CPU. Further, the control signal for the first register plunger, the control signal for the second register plunger, and the control signal for the entire surface exposure lamp are formed by logically combining the above-mentioned signals. That is, C=A・, D=(・)・
A, H=E+L. Other output signals from the CPU include a cassette upper stage instruction signal UL and a total counter control signal TC. (RG is a signal indicating the second registration position generated by a micro switch installed in the optical system running path) On the other hand, the signal input to the 1-chip micro computer is the photosensitive drum home position signal DHP (drum cam and (Generated by a micro switch.) Optical system home position signal OHP (Generated by a micro switch at the end of the optical system scanning path.), Paper feed signal
PF (generated by the drum cam and micro switch) and 1 per 1° of drum rotation.
a pulse signal by a generator 36 operatively coupled to drum rotation configured to generate pulses;
There is a CP. The generator could be an oscillator that generates a series of clock signals synchronously with the drum. Time-sharing display selection signals CT _1-1 , CT _1-2 , CT _2-1 , for operating the display 25 (number of sets) and display 26 (number of counts) in FIG.
CT _2-2 is output. A corresponding 4-bit binary number is output from output terminals a, b, c, and d to operate the seven segments of the selected display. Also, key groups 21, 22 for numerical values and various commands,
The signal from 23, the match signal output when the upper and lower cassette sizes match, and the size signal indicating whether the selected cassette size is full size or half size are determined by the time-sharing display selection described above. Signal CT _1-1 , CT _1-2 , CT _2-1 ,
CT _2-2 and 4-bit parallel PI in time division
1 to PI4 are input to the CPU. Furthermore, this message is output when no cassette is inserted for the upper or lower selection, when there is no paper in the selected cassette, and when the "STOP" key on the operation panel is pressed during copying. Ru
The STOP signal and the copied paper are on the detector 2
The CPOS signal that is output when ejection is detected (when the copy tray is reached) in (Fig. 1) is input to a 1-chip microcomputer. 4 Computer and Peripheral Circuits Figure 7 shows a 1-chip microcomputer manufactured by Rockwell Corporation used in the present invention.
For details on the PPS4/-1 circuit diagram, please refer to the PPS4/1 manual. FIG. 6 shows a circuit diagram of the present invention. In FIG. 6, the relationship between the signal names of the one-chip microcomputer PPS4/1 and the control signals of the present invention is shown. DI/O is CT1-1, DI/1 is CT1-
2. DI/2 is CT2-1, DI/3 is CT2
-2, DI/4 is B, DI/5 is E, DI/
6 is F, DI/7 is G, DI/8 is I, DI/
9 is TC, SERIALOUT is UL, RI/5 is A, RI/6 is J, RI/7 is K, RI/8
is L, RI/ is a, RI/ is b, RI/ is c, RI/ is d, INTO is CPS, INTI is
STOP, PI1 has keys “0”, “4”, “8”,
“MULTI” and “cassette up/down changeover switch” are connected at one end in common. PI2 is connected at one end of keys “1”, “5”, “9”, “SINGLE”, and “AUTO” in common. Connected, PI3
are keys “2”, “6”, “INTERUPT”,
“CLEAR” and “COINCIDENCE” transistors with one end of their collectors connected in common,
PI4 has keys "3", "7", "RECALL", "jam reset switch", "jam kill switch",
Connecting one end of the collector of the “SIZE” transistor, PI5 is PF, PI6 is OHP, PI7
is connected to DHP, PI8 is connected to CP, etc. The "ORIGINAL" lamp on the operating section in FIG. 2 is lit by inputting J to the inverter 601 and creating an OR signal. C inputs B and A to the inverter 602 and AND gate 603, and C=A-
Created by logical combination of. D is and gate 60
4. Input the resist signal, E and A to the NAND gate 605 and inverter 606, and set D=
Created by logical combination (RG・E)・A. H inputs L and E into the OR gate 607, and H=L.
Created by logical combination of +E. Displays 25, 26
The four display devices used in the
The 4-bit signals a, b, c, and d of the computer are decoded and output. On the other hand, the selection of these four display devices is CT1-1, CT1-2,
Setting and resetting are repeated in the order of CT2-1 and CT2-2, and the lighting is performed in a time-division manner. P.I.
The 16 input signals connected to the contacts of the matrix CT1-4 and CT1-1 to CT2-2 are input in a time-division manner. Key “0”, “1”, “2”, “3”
is when only CT1-1 is set,
Keys "4", "5", "6", "7" are set when only CT1-2 is set, keys "8", "9",
“INTERUPT” and “RECALL” are set when only CT2-1 is set.
“SINGLE”, “CLEAR”, the switch that turns on when jammed, “jam reset switch” is CT
When only 2-2 is set, the “cassette up/down switch”, “AUTO”,
“COINCIDENCE” and “SIZE” are read when only the ON signal of the exposure lamp etc. is set. A diode 19 is provided to prevent backflow. Peripheral circuits are shown in FIGS. 6-2 to 6-4. MS13, 19, and 21 are used to determine the cassette size of the upper cassette, and MS15 is used to confirm insertion. They output 0 and 1 signals and have weights of 1, 2, 4 and 8, respectively. MS12, 20, and 22 are for determining the size of the lower cassette, and MS16 is for checking its insertion. They are given weights of 1, 2, 4, and 8. And these are MULTIPLEXER60
9 is input, and switching between this upper stage and lower stage is done by 1.
Codes 1, 2, 4, and 8 are output externally by the switching signal UL from the chip microcomputer. And the decoder 11 is this one,
Decode 2, 4, 8. MS1 for A3
5 is turned ON, the decoded result becomes 0, and the lamp A3 is turned on via the driver 612. Similarly, A4 is 1, U1 is 2, U2 is 3, B4
is 4, B5 is 5, and 8 when no cassette is inserted. Also, if the cassette is not inserted deep enough, MS15 or 16 will not turn on, so the weight 8 will always be 1, so the decoded result will be a value between 9 and 15, and neither lamp will light up. . (See Figure 6-5)
“SIZE” signal is the weight of decoder 611, 0, 2,
4 is input to the OR GATE 613, and when one of these is selected, that is, when it is full size, it outputs "1". This signal is an input signal that changes the sequence timing depending on the size. Also, MS13, 19, 21 and MS12, 20,
The two groups of 22 are MAGNITUDE,
It is input to the COMPARATOR 610, and when both weights match, the "COINCIDENCE" signal is set to 1, and it is determined whether the sizes of the upper and lower cassettes match. When the upper cassette is commanded (the upper/lower switch is turned on), the cassette selection signal UL output from the 1-chip microcomputer becomes 0. Therefore, transistor 621 is turned off,
Since the upper cassette paper detection circuit is selected and the transistor 622 is turned on via the INVERTER 23, the lower cassette paper detection circuit is not selected. However, in the selected upper cassette paper detection circuit, when the paper runs out, the resistance of CdS615 decreases, and the NEGATIVE input terminal 6 of the operational amplifier 13 becomes lower than the terminal 5, so the OPAMP61
The output of 3 becomes "1" and becomes a STOP signal. Similarly, when UL=1, the lower cassette paper detection circuit is selected and functions in the same way. Also, if the “STOP” key on the operation unit is pressed while the main motor is driving, FLIP-FLOP6
17 is set because A=1, and KSTOP=1
become. Therefore, when the main motor is not driving, A=0, so it is not set, and when the main motor is stopped, A=0 and FLIP-FLOP 617, which is set while the main motor is driving, is reset. Output of this FLIP-FIOP617
KSTOP, upper cassette paper detection signal, lower cassette paper detection signal, and no cassette signal are input to the OR gate 618, and any one of these signals becomes "1".
When this happens, “1” is output as “STOP”. 5 Explanation of flag and initial sequence flowchart When sequence control is controlled by a 1-chip microcomputer, each bit in RAM is set and reset in order to temporarily store various operating modes. It is called,
There are about 20 types available. Flag1: Set when the SINGLE key is pressed,
Reset when MULTI key is pressed. Flag2: As a result of determining the paper size, it is set when it is full size, and reset when it is half size. Flag3: Set when the set count and copy count match. Flag4: Set when delay jam occurs. Flag5: Set at the rising edge of the second paper feed signal when entering the second copy cycle from the first copy cycle during multi-copying. Flag 6: Set at the start of the optical system of the second cycle during multi-copying. Flag7: MULTI or during post-rotation cycle
Set when the SINGLE key is pressed. Flag8: Set when a retention jam occurs. (When paper is stopped on the detector, etc.) Flag 9: Set when the drum is not at HP (stop position) when the power is turned on, and reset when it reaches HP and enters the rotation cycle afterward. It is also set when the "SINGLE" key is pressed during the post-rotation cycle, and reset when the "MULTI" key is pressed. Flag10: Set when the number of input pulses does not reach the set value, and reset when it does. Flag11: When entering the rear rotation in a half-size copy cycle, 150 degrees from the optical system inversion position
While the drum is rotating, the optical system is set when it reaches HP, and reset when it reaches the position 150 degrees from the above. Flag13: Set when CT1-1 is set,
Reset when resetting. Flag14: Set when CT1-2 is set,
Reset when resetting. Flag15: Set when CT2-1 sets,
Reset when resetting. Flag16: Set when CT2-2 sets,
Reset when resetting. Flag17: Reset when it is in the upper row, set when it is in the lower row. For example, if the "upper cassette" is specified with "AUTO" and paper runs out, if the lower cassette is the same size and has paper, Flag17 is set and paper is fed from the lower cassette. Flag18: Set when the “INTERRUPT” key is pressed, and reset when the “RECALL” key is pressed. Flag 19: Set when the “Jam Kill Switch” is pressed. This allows the jam program to be ignored even if the paper is not fed during copying. The operation mode is determined by determining whether each of the above flags is set or not, and program execution, sequence operation, jam processing, etc. are proceeded. This is done by changing part of the program by shorting or opening the parts related to the terminals for inputting signals to the computer, thereby eliminating unnecessary processing operations during testing. 5-1 is a system flowchart of a sequence program stored in the ROM of a 1-chip microcomputer that satisfies the timing charts in Figures 3 and 4 and the specifications of the operating section.
- Shown in Figure 5-6. This system flowchart will be explained according to each step. In steps 1, 2, and 3, in order to select the transfer paper size lamp on the operating section and detect the presence or absence of cassette paper, the upper and lower signals UL are set or reset according to the instructions of the upper and lower selection buttons. SUBP 4 is a display digit signal switching subroutine whose details are described in steps 261 to 284. This SUBP is used to change the display digit signal while counting pulses CP for sequence control, or when changing another input signal on the program. When you have it, this SUBP is always passed through the flow. As a result, the display can be dynamically switched and used at approximately 1/4 duty (usage rate), and therefore the display can appear to display continuously without flickering. When the power is turned on, if the optical system is not at the home position HP, repeat 4-5-6 to move the optical system backwards.
When OHP is reached, press 7 to stop reversing. Next, if the drum is not at the home position, 8-9-1
Repeats 0 to search for DHP, and when DHP is detected, it becomes 1
Perform steps 1-12-52-53 to 62. As a result, image exposure and image formation can always be performed from an accurate position, and the reliability of image quality can be increased. at 55-56
This is provided to prevent chattering of the detection signal caused by the microswitch which rotates one more time after detecting the DHP and detects the next DHP at 58-59. The relationship between this timing and the flowchart is shown in FIG. When the optical system or drum is not in HP, the display only shows "00" and "00". Input using the numeric keypad (Figure 2) is only possible when the optical system reaches HP and the drum rotates more than once and reaches HP. If the OHP is turned on when the power is turned on.
If both DHP is detected, 4-5-78
-9-11 and immediately 13-14-15-
16 enters the key reading routine. 6. Explanation of the flowchart of the half-size sequence Figures 3-1, 3-2, and 3-3 show the timing and timing for copying two half-size sheets.
Since this is a chart, we will now explain the flow when 2 is entered in the display 25 (number of sheets set) in FIG. 2 using the numeric keys and the "MULTi" key is pressed. Tenquiltin 13
-14-15-18 and enters the sequence routine 19 and below. 19 indicates the point ○a in Figure 3-2. Reference numerals 20 and 21 indicate the sections marked with ◯ in FIG. 3, indicating that up to 60 input clock pulses are counted. Also, in this section, the digit signals on the display are switched sequentially through SUBP, and the apparent
Indicates that the display is lit in parallel with sequence control. 22 indicates that J (transformer switching) is turned on when CP is counted 60 times. This increases the AC corona discharge voltage. 23,2
4 refers to the section ○D in Figure 3-2, and the paper feed signal
This is a routine that waits for PF to be input. When reaching the point ○O in Figure 3-2, if the STOP mode has been entered before this point, the timing diagram will be as shown in Figure 3-2. Therefore, No. 5-1
In the figure, this is determined in step 25, and J, K
Jump to 51 off. In addition, 51 is the section of ○o, 52 to 56 is the section of ○ka, 57 to 59 is the section of ○ki, 60 is the time of ○ku, 61 is the section of ○ke, and 62 is the time of ○ko. It shows. Therefore, an emergency stop immediately after the start is possible without wasting paper, and the delayed turning off of the lamp prevents uneven charge removal on the drum. If up to the point of ○o
If the mode is not in STOP mode, the process advances to paper feed B 26 and beyond. 26 refers to ○o, the section from 27 to 30○sa,
Wait for DHP dropout due to drum rotation to be detected. 31 to 36 indicate the section of ○, and wait for the PF to pass. Further, the PF is read in synchronization with the clock signal CP, and the CP is counted by 34 at the same time as it is determined whether the PF is missing. 37 refers to the time of ○ce. Reliability can be increased because the next step is executed only after determining whether the DHP or PF is missing. Also, at this time 38-4
The remaining jam check is performed after the second COPY cycle indicated by 5, but since this is the first copy, it is determined at 38 that Flag 6 is not set, and the process jumps to 46 and thereafter. 46 to 49 indicate the interval of ○so, and the time of ○o (at 31, the number of pulses is 67
This is the period in which the count is waited for until the CP, which has started counting from (set to 67), reaches the set value of 67. The time point reached is 50, that is, the time point ○ta in FIG. At this point, the developer plunger, optical system advancement motor, and exposure lamp are turned on, as well as the pre-exposure lamp G. However, in the case of half size, G is only used in the first copy cycle.
It turns on, and does not turn on after the second copy. At this point, it is necessary to determine whether it is half or full (65) and whether it is the first copy cycle (63). This is shown in 63 to 66. ing.
Since this is the first card of the half, I jump to 63-66 and turn the G on. 87 counts again from point ○ta
Start CP counting. During this process, the routine waiting for the OHP to turn off is 67 to 70, which indicates the section marked with ○ in Figure 3. The time point when the OHP turned OFF is 71, which is indicated by ○C in Figure 3. Therefore, the accuracy of the sequence is increased because the next step is only proceeded to after determining whether the OHP is missing. Also, at this point, a delay jam check is performed in the case of a half "MULTi" copy. After entering the second and subsequent copy cycles, a jam check is performed for the paper from the previous copy cycle, so since this is the first copy cycle, it is ignored in the determination of Flag 6 in 73, 72-73. →
Jump to 81. This half delay jam check is shown at 72-80. Furthermore, since the blank lamp is kept on until the point ○C, it is possible to eliminate potential unevenness in the unexposed area when the exposure lamp rises.
81 to 82 are the sections in which the count is waited for to reach 87, which corresponds to the section indicated by ◯hi in Fig. 3. Further from here
105 counts are 84 to 85, indicating the section to ○. 86-1 when it reaches 105 counts
01 and 112, which corresponds to the half size inversion position in FIG. At this point, as shown at 86 to 91, it is determined whether or not there is no more paper in the designated cassette. (86) To determine whether to switch to another cassette when the paper runs out, it is necessary to determine whether the cassette is set to AUTO (87), and whether the cassette size is the same (88). If the above conditions are satisfied, the process passes through steps 85 to 89, switches the UL at 90 or 91, and proceeds to steps 92 and subsequent steps. In addition, the STOP judgment in 86 includes cases in which the STOP key is pressed and the cassette is removed, in addition to the case where the paper runs out, so in these cases, the UL is switched once, but the UL is switched again in 101. Since STOP is determined, there is no problem because the rotation is continued after 112 and is returned to the original state when returning to 13 of the key reading routine. Furthermore, since the half-size optical system is inverted at the point of ○, it is determined at 92 whether it is half or full, and if it is full, it passes through 93 and returns to 1 in Figure 5-4.
Proceed to 90 and above, but now it is a half case,
Proceed to 94 onwards. Then, from 96 to 102, the copy count (CT ₂ +1) is completed and compared with the set number CT ₁ , and if the two match,
When the STOP mode is entered, if a jam occurs before the point ○ in FIG. 3, the process proceeds to the post-rotation routine after step 112. 1 if not above
Go to routine 03-111. In this routine, if the STOP mode is entered within the time when the paper feed PF signal is input from the reverse position of ○E (as shown by timing 3 in Figure 3), the transformer switch J is turned OFF at the moment the STOP mode is entered. (106), wait until the count reaches 150 and jump to the post-rotation routine after 134. The flow of this time 103-104-1
05-106-107-109-103-10
It becomes 4-134. If the STOP mode does not occur, the 103-104-105-107-
Repeat 109-103..., and when PF turns ON, 103-104-105-108Flag5
is set, and the process returns to the point where the paper feed roller control signal B of 26 is turned ON again (indicating that the second or subsequent copy cycle has started). In FIG. 3, this refers to the time of ○chi, but from this point on, the same control contents as those of ○o to ○ta in FIG. 3 are basically repeated. However, since the optical system reverse (F) stop and delay jam check are included in the second and subsequent copy cycles, only this will be explained in additional detail. The second time 32-36 indicates the time from when the DHP turns OFF until the PF turns OFF (the section circled in Figure 3).If the optical system reaches OHP within this time, 35-36 Turn off street F. Since the backward movement of the optical system and the rotation of the drum motor are asynchronous, there is variation in the time the optical system reaches OHP. Therefore, the section marked ○sa in Figure 3 (27-3
0) and ○2 interval (46-49) respectively.
Routine to detect OHP and turn F off (2)
9-30, 48-49) are provided. The delay jam check for the first sheet of paper is performed when the optical system moves forward (E) during the second sheet copy cycle.
This is done by detecting the arrival of paper to the detector 2 when the OHP is turned off (on) and the OHP is turned off, so this refers to the time point marked with a circle in Fig. 3. This is checked in the routines 72-80 of Figure 5-2. If paper is not detected after a delay, 72-73-74-75-76-
77-78-79-80, Flag4 is set, the delay jam is memorized, the copy count _CT2 is decremented by 1, and the jam solenoid I is turned on. If the jam killer switch is turned on and that instruction is read in key entry routine 13, then 77
~80 are ignored. The activated I is turned off at point 83 (at point ○ in Figure 3-2).Therefore, the machine can be test run without paper feeding. or,
Figure 3 only shows the timing diagram for the case of two-sheet copying, but if this is three or more sheets of copying, the first sheet of paper retention jam check (detector's paper stop check) is This is done when the PF turns OFF in the third copy cycle. This is noted in 38-45.
If the first copy has a retention jam, it passes through 38-39-40-42-43-45 and 1
Enter the post-rotation routine after 35. At this time
Remember that Flag 8 is set and there is a retention jam, and when it is half, the copy count is already in the third copy cycle, so copy count CT ₂
Subtract -2. However, if it does not stay, the process advances to 38-39-41, outputs an addition signal TC of a total counter (not shown), and increments the counter by 1. This TC is turned off at 50. Next, in Figure 3-2, there is a delay jam at ○.
Let us assume that the check has been completed and the second copy cycle has reached the optical system reversal position. At this point, the number of sheets set in 99 and the number of sheets counted match, so Flag3 is set at 102, the fact that the mode ends due to coincidence is memorized, and the post-rotation routine from 112 onwards is entered. 113 to 133 indicate the section marked with ○mo in Figure 3, where CP is counted 150 times, and in parallel with this, wait for the optical system to reach OHP within that time, and when it reaches OHP, turn OFF F (115 -11
6) At the same time, check the retention jam of the first sheet of paper (SUBI from 117 to 126), and
Set Flag11. Once this is set, from now on, even if the optical system is in OHP, the retention jam check routine 118-125 will be executed at 117.
is ignored. This point refers to the point marked ○ in FIG. 3. Therefore, the retention jam check during post-rotation is performed only when the optical system reaches OHP. if,
If no delay jams have occurred before this point,
If the first sheet of paper causes jamming without instructions to kill the jam, call 117-1.
18-119-120-121-123-124
-125-126, sets Flag8, remembers that the retention jam has occurred, subtracts -2 from the number of copies since it is half size, and sets the jam solenoid I.
Turn it ON (chart in Figure 3) and then
Flag11 is set, so jump to 117-127. However, if the optical system reaches OHP,
If there is no stagnation, call 117-118-11.
9-120-122-126 and turns on the total counter signal TC. Meanwhile, this CP is 150
The start key input routine SUBH from 127 to 133 is always passed within the counting time, but this is because the number of copies matches the set number and the number of copies is entered into the post-rotation routine, or the post-rotation routine is entered in SINGLE mode. Only if it follows, again,
From the point of ○ in this figure 3-2, MULTI or
Since it accepts the SINGLE key, this is the routine that reads these keys. For example, if the MULTI key is pressed, 127-128-129-1
30-133, and if the SINGLE key is pressed, 127-128-129-131-132-
Pass through 133. Therefore, when using the MULTI key,
Set FIag9 to 0 and FIag7 to 1. When pressing the SINGLE key, set FIag9 to 1 and FIag7 to 1. FIag9 is used to determine whether it is multi or single, and FIag7 is used to remember that a restart command was entered during backward rotation. When the CP count reaches 150, it is 134, indicating the point in Figure 3. 135, 136, and 137 are provided for safety because the point at which the optical system reaches OHP varies. 138-140 indicates the section ○yo in Fig. 3-3, which is the section in which the CP counts 38 counts from the time ○Y. The time when the count reaches 38 is the point ○a in Figure 3-3. Here, I or TC, which was turned ON by the retention check at the time ○ya, is turned off (141), and the last copy paper is turned off. This is also the time to perform a delay jam check. The flow at this point is shown at 142 to 149, and a jam check is performed if no retention or delay jam has occurred before this point and there is no command to kill the jam. If jamming, turn on I
Then, set FIag4 and subtract -1 from the copy count. However, in the case of single mode, this subtraction is ignored. (147). 150-152 is the third -
Indicate the interval in Figure 3 and count 60 CPs. Then, when this value is reached at 153, I, which was turned on in the jam check, is turned off. Third
In Figure -3, it refers to the point of ○. 154-156 are
The section circled in Figure 3 shows the waiting time to reach the OHP. In FIG. 3-3, SUBHs are provided at 140, 152, and 156 in order to receive the MULTI and SINGLE keys in the section from ○M to ○Ro. When the OHP is reached (circle in FIG. 3), the motor on signal A is turned off at step 157. 158 indicates the section of ○wa, and 159 indicates the time point. If a delay or a jam has occurred before this, the jam release routine from 160-161 to 182 onwards is entered. If not, and
If there is no jam killing command (162), the last copy paper is checked for remaining jams. If the retention check is OK, 164, 165,
Turn the TC ON and OFF at 166, and if the set number and copy number match and the end mode is entered, 167-
Clear the copy number with 168, and then during post-rotation
If the MULTI or SINGLE key is not pressed, the process passes through steps 169-175 and returns to the key reading routine in step 13. If pressed, MULTI
For keys, pass 169-170-171, 1
73 determines whether the set number is 0, and if it is 0, it is 1
75 and enters the key reading routine of 13, and the MULTI key being rotated afterward is ignored. If it is not 0, it passes through 173-174 and jumps to 19 to start the copy cycle again. On the other hand, if the SINGLE key is pressed, the process passes through 171-170-172-174 and jumps to 19, whereupon the single mode copy cycle begins again. In this way, it is possible to accept a start command using the input means (multi-key, single key) while the rotating body (drum 30) is rotating after completion of a series of image forming operations, and when the start command is received, the start command is started. Data (Flag7) indicating command input is set in the first area of the data memory (RAM), and it is determined whether or not the data is set in the first area of the data memory after abnormal conveyance of the recording material is determined. None (Step 169 in Figure 5-3), if abnormal conveyance of the recording material is not detected, the first
If the data is not set in the area, the image forming operation is terminated, and if the data is set in the first area of the data memory, the image forming operation is started according to the numerical data set in the second area of the data memory. On the other hand, if abnormal conveyance of the recording material is detected, abnormal processing is executed and a new image is formed even if the data is set in the first area of the data memory. This prevents the start of the operation. If it stays in the stay check above, turn I.
Turn ON and OFF, and subtract 1 from the number of copies. 163-
176-177-178-179-180-18
1). However, if it comes in single mode, -1 is not subtracted. 182 to 189 are the jam release routines of I.
Jam mechanism latched at ON and OFF (No. 9-2
The routines 182 to 184 wait for the jam switch that is turned on to be released (reset button turned on) by the button shown in the figure. been canceled
When it becomes OFF, proceed to 185 and after, and here the MULTI or
For SiNGLE, MULTI for MULTI,
SiNGLE is waiting for SiNGLE to be pressed. Therefore, if MULTI was previously pressed,
It passes through 185-186-187-188 and jumps to 19 to copy the remaining number of copies. For SiNGLE, it passes through 185-186-187-189 and also jumps to 19. Therefore, other combinations are not accepted. 7 Description of Flowchart of Full-Size Sequence Next, the flows of FIGS. 5-4 and 5-5 will be described with reference to the full-size timing chart of FIG. 4. ○A to ○Ho in Figure 4-2 are the third
Since the flow is the same as the flow up to that point in the figure, the explanation will be omitted. Therefore, the point marked by ○ is the half-size optical system inversion position, but this time it is full-size, so the point from here on is different from the half-size. Therefore, this circle points to flows 86 to 92, but in the size determination at 92, it passes through 93 and jumps to 190 and beyond. These 190-191 advance further from the half-size optical system inversion position.
This routine waits for 150 CP counts, and refers to the section in Figure 4-2. and 150
The point at which the count is reached is the full-size optical system inversion position (time point 4 in FIG. 4). In the flow, it refers to 192 to 198. In this way, since the reversal position of the optical system is selected based on the count number for each size from a subsequent predetermined position or timing rather than the start point of the copy cycle, a highly accurate reversal position can be obtained. 192 because it is inverted position
Turn off E and G and turn on F and L. Furthermore, in multi mode 193, if no jam has occurred before this point (194, 195), add 1 to the copy count in 196, and if it matches the set count number, 197 will change from 199 to 23.
Proceed to 232 via 1. When it doesn't match again
When in STOP mode, it goes through 231 and then goes to 23.
Jump to 2. Therefore, only if they do not match and the mode is not STOP mode, the process proceeds to 200 and thereafter. Therefore, at this point, if you proceed to 200 or later, or if you proceed to 2
It is divided into two systems for those who advance to 31 or later. First 2
The flow after 31 will be explained. Cases that enter this flow are when in single mode (193), when a jam occurred previously (194, 195), when the set count and copy count match (197, 199), and when they do not match, STOP mode (197, 198), and it can be considered that the time point in FIG. 4 has apparently shifted to the time point in FIG. Therefore, since it is currently the first copy count, it can be assumed that the sequence moves to → only when the STOP mode is entered and the sequence is executed. Since this is the routine for the first of two copies, we will explain the case where the copy count is incremented by 1 and the process advances to 200 or later. 200-201 refers to the section in FIG. 4-2, and the time point when 38 cp counts is indicated by in FIG. At this point, a delay jam check of copy paper is performed, and the check flow is shown at 202-208. This jam check is effective when there is no jam kill command (203). If the copy paper is delayed, Flag 4 is set, jam solenoid I is turned on, the copy count is subtracted by -1, and J is turned off. . This timing diagram is the fourth
It is written on the chart in the figure. Also, this copy count subtraction is performed in single mode (20
6) is ignored. Next, the time for counting 112 cps indicated by 209 and 210 corresponds to the section of FIG. The point at which 112 counts were reached is shown in Figure 4. At this point, at the time of said
It is determined whether a delay jam has occurred (212) at the same time that I is turned off. If a jam occurs, as a result of the determination in 212, the process proceeds to 213 and subsequent steps to satisfy the timing chart in FIG. 4. K at the beginning
Turn it off (213) and wait for the optical system to reach OHP at steps 214 and 215. This section refers to the section circled in Figure 4. The fourth point is when OHP is reached.
Indicated by the circle in the figure, turn F off, (216), 2
Search for the next DHP at 17,218 (circled section in Figure 4), and when it reaches DHP, move to 220,2.
Wait for the DHP to turn off at 21 (○ area in Figure 4). When DHP turns off, jump to 154 and beyond, wait for DHP to come again (circle section in Figure 4), and end the copy operation. Determination of jam at the time of if (212)
So, if it's OK, set the OHP to 223,2.
Wait at 24 (section in Figure 4), and when it comes, 22
Turn F off at step 5 (see Figure 4), and wait for the PF signal to arrive at steps 226 and 227 (area of Figure 4). The time when PF is reached is the point ○ in Figure 4, and if it is in STOP mode at this point, the flow will satisfy the timing of the chart in Figure 4, and STOP will be determined at 228.
Proceed to 22 onwards. Turn off JK at 229,
Wait for PF to turn off at 257-260,
Look for the DHP that will come after the next rotation and stop the copy cycle. If it is not in STOP mode, set FIags 5 and 6 at 230 and jump to 26 to enter the second copy cycle. Therefore, ○chi to ○mi in FIG. 4-3 follow the same flow as ○chi to ○mi in FIG. However, since the retention jam check for the first sheet of copy paper is performed at the time of the copy cycle for the second and subsequent sheets, the check flow is shown in 38-45. If it stays 38-39-40-42-43
-44, jump to 217 and satisfy the chart timing in Figure 4. First, when the number of copies stagnates, JK is turned off, Flag8 is set, and the number of copies is subtracted by -1. After that, the process jumps to 217 and the drum is rotated until DHP is detected, and when it is detected, copying ends. In the copy cycle for the second full-size copy, ○chi~○me executes the same flow as half-size,
The point at which both branches diverge is at the point of ○me. 92 of the flow is the half reversal position. Therefore, the fourth
The section in the figure is the time 190 to 192 explained above, and the time point is the full-size inversion position,
Since the number of copies and the number of sets match in 196, 192-193-194-195-196
J via -197-199-231
OFF (primary charging OFF) and proceed to the post-rotation routine from 232 onwards. 232 to 234 indicate the time for counting 38 cp, which corresponds to the section in FIG. At the time when 38 counts have been reached (in FIG. 4), the delay jam check for the last copy sheet is performed, and this is shown at 235 to 241 in the flow. Here, even if a jam has not occurred before (23
5), and when a jam check is performed without a jam killing command (236) and a jam occurs, the jam solenoid I is turned ON and the copy count is subtracted by -1. However, in the single mode, the copy count is not subtracted (240). 242 to 244 refer to the section in FIG. 4, which is the time during which 60 cp counts are being counted. When this count is reached, the above 241
Turn OFF the I that was ON (as shown in Figure 4). Furthermore, at 246 to 248, count cp by 52 (as shown in Figure 4), and at 249, turn off bias K (see Figure 4).
). Wait for the optical system to reach OHP at 250-252 (section of Fig. 4), and turn F at 253.
Turn it OFF (as shown in Figure 4). After that 254~
Wait for the paper feed cam ^pF to turn ON at 256 (in Figure 4), and then wait for it to turn OFF at 256 (in Figure 4).
Wait at 58-260. Then, when it turns OFF, the drum rotates one more time and waits until it reaches DHP (154 to 156, ○ in Figure 4) to complete the copy cycle. In addition, 234, 244, 248, 252, 25
6,260, the subroutine SUBH is placed in the loop within the time after the point in time.
It is provided so that the MULTI or SiNGLE key can be read. Also, the "INTERUPT" key has the same function as the "STOP" key, and similarly shifts to the post-rotation mode. Moreover, at this time, the display 25,
The 26 set and count numbers are moved to a set of registers in the memory RAM, and new numbers can be entered on the display. After this, execute the flow from the key entry above. When entering the rotation mode after copying is complete, press the ``RECALL'' key, the original value stored in the above register in RAM will be transferred to the displays 25 and 26, and press the ``MULTI'' key again to display the remaining number of sheets. Can be copied. Figure 9 shows devices related to jam safety. Figure 9-1 shows a door switch for safety when handling jammed paper. The microswitch DS that turns the power on and off is illustrated. FIG. 9-2 shows a mechanism for turning off the fuser and DC high voltage related power supplies using a jam solenoid. If a jam occurs, the solenoid SL
is actuated and pulls up the lever 92 with the dowel 91 attached, whereby the release lever 93, which was fixed by the dowel, loses its fixed point and is rotated by the spring 96, turning off the micro switch 94. Therefore, the above processing mechanism stops. This can be canceled by pressing the reset switch 95. However, the main motor rotates the drum to the drum home position where the paper will be ejected. [Effects] As described above, according to the present invention, it is possible to receive a start command during the subsequent rotation of the rotating body before the completion of a series of image forming operations, and when a start command is received, the start command can be input. The data indicating the start command input is set in the data memory, and it is determined whether or not the data indicating the input of the start command is set in the data memory after abnormal conveyance of the recording material is determined. If no start command is detected, a new image forming operation will be started without any further start command if data indicating input of a start command is set in the data memory.On the other hand, if abnormal conveyance of the recording material is detected, Even if the data indicating the input of a start command is set in the data memory, it executes abnormal processing and prevents the start of a new image forming operation. It is possible to quickly prepare or start a new image forming operation without waiting for the completion of the image forming operation, and even if a start command for new image forming is input, If an abnormality occurs in the image forming operation being executed, a new image forming operation is not started, so that unnecessary image forming operations can be prevented.

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【table】 [Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a copying apparatus to which the present invention is applicable, FIG. 2 is a plan view of the operating section in the apparatus shown in FIG. 1, and FIGS. Operation time chart by size No. 4-
Figures 1 to 4-3 are operation time charts for the full size, Figures 5-1 to 5-6 are control flowcharts of the device in Figure 1, and Figure 6-1 is a control circuit in the present invention. For example, in Figure 6-1, CPU is a computer chip element, G is an output gate circuit, M is an input matrix circuit, 2
5 and 26 are indicators, P11 to 4 are input terminals, G is a scanning output terminal, and D1 is a load output terminal.

Claims (1)

[Claims] 1. A process means for forming a latent image on a rotating body and forming an image corresponding to the formed latent image on a conveyed recording material, and an input means for inputting a command to start image formation. , comprising a program memory storing a program for sequentially controlling the process means and a program for monitoring abnormal conveyance of the recording material, and a data memory capable of storing data related to image formation; control means for controlling the process means to execute image formation according to the data stored in the data memory according to a stored program, and monitoring abnormal conveyance of the recording material; It is possible to receive a start command by the input means during the post-rotation of the rotating body before the completion of a series of image forming operations, and when the start command is received, data indicating the input of the start command is stored in the data memory. 1 area, and it is determined whether the data is set in the first area of the data memory after abnormal conveyance of the recording material is determined, and if abnormal conveyance of the recording material is not detected,
If the data is not set in the first area of the data memory, the image forming operation is terminated, and if the data is set in the first area of the data memory, the numerical value set in the second area of the data memory is A new image forming operation according to the data is started without any further start command from the input means, and on the other hand, if abnormal conveyance of the recording material is detected, the data is set in the first area of the data memory. An image forming apparatus characterized in that the image forming apparatus executes abnormality processing and prevents the start of a new image forming operation even if the image forming apparatus fails.