JPS6090351A - Image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to an image forming apparatus.

Examples of the present invention will be described below using a one-chip microcomputer (
An example of controlling various functions of a copying machine using a CPU (hereinafter referred to as a CPU) will be described in detail.

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 and a movable reflection mirror 8, a movable reflection mirror 6,
It is composed of a lens 17 and fixed reflection mirrors 18 and 19.

Therefore, the original is integrated with the illumination lamp 9 as indicated by the arrow A in the figure.
While the optical path length is kept equal by the movable reflective mirror 8 that moves in the direction shown and the movable reflective mirror 6 that moves in the same direction at a moving speed of 1 of the movable reflective mirror 8, the lens 17 and the fixed reflective mirror 18 The photoreceptor is subjected to slit exposure through .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 300 has a photoreceptor whose photoreceptor layer is covered with a transparent insulating layer, and the photoreceptor is first positively charged by a glass charger 12 that is supplied with a positive high voltage current from a high voltage power source (not shown). I am made to do so. 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 drum surface (photoreceptor) by full exposure by the full surface exposure lamp 33, and the developing device 3
I'm in 1.

Development is performed by powder development using a sleeve method, and the electrostatic latent image is visualized.

Next, the transfer material from the cassette 21 or 22 is fed to the paper feed roller 2.
The paper is fed by No. 4, conveyed by No. 10-225 and No. 20-228, temporarily stopped by timing roller 29, rotates roller 29 in response to a 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).

The 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 current from a high-voltage power source.

After the copy material has been transferred, it is separated from the drum by a separating roller 26, guided to a heat fixing roller 4, and fixed thereon.Then, excess charge is removed by a static eliminator 3, and then the copy material is removed by a discharge roller.
It is discharged onto the tray 20. Copying is now complete, and the remaining toner on the drum is cleaned by the blade 11 pressed against the surface of the drum (photoreceptor), allowing the next cycle to be repeated. To avoid complexity, a detailed description of the drive system and sea fences and timing of each process will be provided later.

A cam provided on the drum operates switch PF to generate a paper feed signal. The switch DH'P generates a drum home position signal to stop 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, 1
5 is an optical motor, and 14 is a rung for pre-exposure to uniformly fatigue the photoreceptor in advance of 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.

The operation panel of this device is shown in Figure 2.

The operator can interact with the CPU via this operating section. That is, the CPU indicates responses to the inputs from the key groups 21, 22 and 23 on the displays 24-28. The operator can set the desired number of copies up to 99 on the display 251C by pressing the numerical keys 0 to 9. ” C.L.E.
The "AR" key is used to set the contents of this display 25 to O.The "MULTI" key is used to set the contents of this display 25.
When this key is pressed once, the machine enters the copying operation and when the optical system reaches the reversal position, the value on the display 26 changes from O to +1.
be done. Then, copy the set value on the display 25.
When the values on the display 26 indicating the number of sheets
The py operation mode becomes the end mode, and when the copy operation ends and the photosensitive drum stops, the display 26 is set to 0''.
Return to '. Therefore, the value initially set using the numeric keypad still remains on the display 25, so if you want to copy the same file for another document, use MULTI again.
Just press the key.

However, the value of the display 25 for this ``MULTi'' key is ``
When it is 0pa and any of the display groups 24 is lit, it is ignored.

"MULTi" copy in progress copycount
When the number does not reach the set count number, "5TO
When the "P" key is pressed or any of the display groups 24 lights up, the copy operation at that point is terminated and the copy cycle is terminated.Thus, for example,
cop for t c o u n t ” 6 ”
If the above state occurs when ycount"3'',
The indicators 25 and 6'' are at rest, and the indicator 26 is at rest at 3''. At this time, the key group 22 is fully open.

Further, after the copy operation is completed, all of the key groups 21 and 22 are accepted.

5INGLE” key is SET count, cop
A single copy operation is performed regardless of the y count. Therefore, using this key, interrupt copying is possible for only one copy. For example, when the first operator sends 6 copies to the display 25, and when the copycount reaches 3 copies, the second operator requests to interrupt the copying of 1 copy, the first operator sends "5 TOP"
When the ``S1NGLE'' key is pressed, the copying is stopped once the 3 sheets have been copied, and the second operator sets his own original.'' When the ``S1NGLE'' key is pressed, the display 25 shows ``6'' and the display 26 remains stationary at 3'', and the single sheet copy for the second operator is completed. Therefore, the first operator can make 1A93 copies by pressing the "Ti" key again.If the desired number of copies to be made is not one but multiple copies, " This can be done using the "INTERtJPT" and "RECALL" keys.The first operator is set count I+6", copyc
ountII 3 When stopped in response to the second operator's interrupt with I+, the second operator
When you want to interrupt Qpy, the second operator is "
Press the “INTERTJPT” key and set count
Temporarily save the number ``6'' and the copy count 113'' to another memory, and turn on the 1nterupt lamp 2.
After turning on 8, use the jen key to set 9 "2" as the set count number and enter L, "MU"
Press the ``LT i'' key to complete the two-copy process.After this, press the ``RECALL'' key to recall the gl operator values ``6'' and ゛°3pa to the display 25.26. 1 operator again” MUL
You can make copies of the remaining three sheets by pressing the T i ” key.

The display lamp 27 "0RIGINAL" indicates that the original can be set or replaced, and goes out during copying. Therefore, the light will turn on when the optical scanning of the last paper copy is completed, so immediately replace the original.
By pressing the "or °'S INGIJ'" key,
You can start copying again.

Indicator lamp 28 "INTERUPT" is °' IN
When you press the ``TERlJPT'' key, it lights up and the ``RECAL'' key is pressed.
It disappears when you press the "L" key.

JAM' lights up immediately when copy paper jams, causing the copying to end mode.

Then, at this time, the display 26 causes the CPU to increment -1 or -2 depending on the location where the paper jam occurred and the paper size, thereby ending the copying. In addition, in the event of a jam, the operator opens the door of the machine and removes the jammed paper, so the total counter that calculates the copying fee is counted only after the paper tray is stored, and JAM L sheets are not counted. . In other words, both the copy count display and the total counter are guaranteed to count in the event of a jam.

The display "To R5UPPL, Y" lights up when the toner in the developing unit runs out, and does not affect the start or continuation of copying.

"PAPP2R-5UPPLY" lights up when there is no more paper in the selected cassette, and prohibits the start of copying or terminates the continuation of 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.

Switching button 7 “UPPER-CaSSETTE”
, "LCWER-CASSETTE" selects the upper or lower cassette, and 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 machine will automatically pull out the paper from that cassette and continue copying only when there is paper of the same size stored in another cassette. can do.

(Control Circuit) Fig. 6-1 shows a control circuit for inputting and outputting to the computer, and Fig. 6-2 shows a peripheral circuit for inputting and outputting. In the figure, the CPU includes a memory that stores the control program shown in FIG. 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. A computer chip device whose circuitry is contained on a single semiconductor substrate. The details are shown in FIG. The output a=d is connected to a display device (25, 26) via a segment decoder 608 in order to display the number of sheets on the display device (25, 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 G 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 the output input circuit. 60
3.604 is an AND gate, 601.602.606 is an inverter, 605 is a Nant gate, 607 is an or game
), 609 is a paper detection circuit using a transistor.

Each digit of the display is displayed using seven segments, and the digit is selected by the output CT signal from the chip.

This consists of 10,000 outputs that are output alternately in the order of the numerical pot CT,
A segment of the required digits is selected by the 4-bit output simultaneously outputted from a % d, and a dynamic display is performed in which display units are displayed alternately in order O Output CT, , , CT, , , CT, = , CT
The input from the input switch that intersects with 22 is similarly dynamically inputted. 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 and the like is sequentially outputted with a clock for computer program processing, whereas the output for operating a control load is an output of a length required for the load to be turned off. Also, by using it as an interface circuit and powering up the signal from the gate circuit, it becomes a nnnoid.

There is a driver circuit (not shown) that drives lamps and the like. 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 triac 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 this intersection serves as a switch, which corresponds to the input command section.

If there are X scanning lines and y input lines to the processor, a maximum of x''y switches are possible.

In addition, the ROM included in the computer chip element has a master program for executing the sequence of the copying machine stored in advance in a sequence room and is embedded in each address, and its contents are programmed each time a specific address is set. It is a read-only memory that can be read out, and is itself a well-known matrix circuit in which programs are programmed in binary code in sequence from address 0 to the required final address (key entry program, equipment operation program, machine termination program, etc.). ). Also, the RAM can store the number of copies and files.

A readout memory for temporarily storing control signals during process control; a known memory for storing a set of binary code;
Multiple flip clocks.

A plurality of sets are formed, and an arbitrary set is selected by an 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 is A4
．． B5. In the case of a medium size such as U2, Fig. 4 is A3.
．． B4. For full size products such as UL. A control timing chart and control load are shown.

'U+, U2 Id, U+ with universal cassette
f)" U2 (7) Stores paper of any size that is full. SW is the switch that turns on the power to the device, and at the same time lights up the input indicator lamp. M1 is the motor that rotates the fixing roller, and LI is the one that allows copying. Wait lamp H, B2 indicates the fixing heater built into the fixing roller, the cooling blower has a motor that cools the heater, the main motor rotates the photosensitive drum, and the paper feed roller P
L is a plunger for lowering the constantly rotating paper feed row 224; tit register PL is a plunger for driving the HM10-RA 25; second register PL is a plunger for driving the timing roller 29; developing device PL is for stirring the developer powder. Plunger that drives the screw.

ATR detection is an optical detector to detect a decrease in toner concentration, hopper HOP is a toner supply device operated by the detector, pre-exposure tape is a lamp that uniformly irradiates the photoreceptor in advance, optical motor group-F is a document The optical motors M and -B are motors for moving the optical system backwards, the exposure lamp L is a lamp for irradiating the original image onto the photoreceptor, and the blank exposure lamp is 2 lamps. L4 is a lamp that uniformly exposes the photoconductor when the original is not exposed) L5 is a lamp that uniformly exposes the photoconductor during the entire surface exposure process, 1
The secondary transformer Tr is a primary charging transformer, and the bias transformer Tr2 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 Tr3 operation control signal for neutralizing static electricity, paper feed roller plunger PL on the upper stage of the cassette
operation control signal ■, optical system advance motor M, -F, exposure lamp L1. Control signal ■ for developer plunger PL, control signal [F] for optical system backward motor M, -H, front exposure lamp -
Control signal ◎.

Jam indicator lamp, reset plunger control signal ■,
Control signal for AC transformer voltage switching ■.

The control signal (2) for the secondary transformer Tr, the bias transformer Tr2, and the control signal (2) for the blank exposure lamp are directly output from the CPU. Further, the control signal ◎ for the first register plunger, the control signal ◎ for the second resistor plunger, and the control signal ◯ for the entire surface exposure lamp are formed by logically combining the above-mentioned signals.

That is, C=A-100, D=(RG-B)・A', H=E+L
It is. Other output signals from the CPU include a cassette upper stage instruction signal UL and a total count control signal TC. (, RG is a signal indicating the second registration position generated by a microswitch installed in the optical system running path) On the other hand, the signal input to the l-chip microcomputer is the photosensitive drum home position signal DHP (drum ) Optical system home position signal OHP (generated by the micro switch at the end of the optical system scanning path), paper feed signal PF (generated by the drum cam and micro switch) CP) and a pulse signal CP by a generator 36 operatively coupled to drum rotation designed to generate one pulse per degree of rotation of the drum.

The generator could be an oscillator that generates a series of clock signals synchronously with the drum.

Time-sharing display selection signals CT+-I, c'r, -, CT2-1 for operating the display 25 (number of sets) and display 26 (number of counts) in FIG.

CT, , is output. A corresponding 4-pit binary number is output from output terminals a, b, c, and d to operate the selected seven segments of the display. In addition, numerical values, signals from the key groups 21, 22, and 23 for various commands, and Coi output when the upper and lower cassette sizes match.
nc 1dence signal and the selected cassette size is FIJLLS IZE or IF (ALF 5IZE;
The 5IZE signal indicating this is the time-division display selection signal C'L-+, CT+-2.

4 in time division by CT2-1, CT2-2, and ■
Bits are input from PII-PI4 to the CPU in parallel.

Furthermore, this message is output when no cassette is inserted for the upper or lower selection, when the selected cassette is not filled with paper, and when the ``5TOP'' key on the operation panel is pressed during copying. The 5TOP signal and the cpos signal output when the C0PY paper is detected to be ejected (when it reaches the copy tray) by the detector 2 (Fig. 1) are input to the 1-chip microcomputer. Ru.

[Description of 1-chip microcomputer and its peripheral circuits] Figure 7 is a circuit diagram of the 1-chip microcomputer PP54/-1 manufactured by Rockwell Corporation used in the present invention.For details, refer to the PP54/l manual. Please refer. FIG. 6 shows a circuit diagram of the present invention.

In Figure 6, l chip microcomputer PP
The relationship between the signal names of 54/1 and the control signals of the present invention will be described below.

DI/60 fi CTl-1, DI/cil fi
CTl-2, DI/δ2 is Cr2-1. DI/631
d Cr2-2. DI15416. B, DI/δ
51dE, DI/δ6 is F, DI/67 is G, D
I/δ8 is I, DI/69 is TC, 5ERIALOUT
is UL, RI/65 is Ar, RI106 is J, RI
/E71ri K, RI/δ8 beam, RI/6 is a
, RI/61d b, RI/ci i”l: C,
RI/ci u d, INTOf'J, CPc1S
.

lNTl is 5TOP, PII is key “O”, “4
”, “8”.

``Koiru TT'' and one end of the ``cassette up/down selector switch'' are connected in common, and PI2 is the key ``1''.

“5°′,”9″’, “5INGLE”, AUT
PI3 with each end of the O” switch connected in common.
1. ``i key'', 2 I+.

"6", "INTERUPT", "CLEAR",
"C0INCIDENCE" One end of each collector of O transistor is connected in common, PI4 is key "3",
7”, “RECALL”.

“‘Jam reset switch’, ‘jam killer switch’
, ``5IZE'' transistor collectors are connected at one end, PI5 is PF, PI6 is 0L (P.

PI7 is connected to DHP, PI8 is connected to cp, etc.

The ORI'GINAL'' LAMP of the operating section in Figure 2 is 1m.
Input J to the positive IERI, create an OR signal, and it will light up.

C is 1 crime RTER602, A) B to GATE603
It is created by inputting and A and logically combining C=A-H. D is A
NDGATE604. NAND GATE605.
Input the Regis:=coat signal decoy, E, and A to the criminal RTER 606, and create a logical combination D=([-E)・A. H is L for ORGATE 607
and E are input, and it is created by the logical combination of H=L+E. The four display devices used in the displays 5 and 6 are divided into seven segments, each segment has four wires connected in common, and the seven signals connected in pairs are sent to the decoder and driver 8. , l-chip microcomputer a, b
,c.

The 4-bit signal of d is decoded and output.

On the other hand, the selection of these four display devices ranges from CTI to 1°CT.
l-2, Cr2-1. Setting and resetting are repeated in the order of Cr2-2, and the lighting is performed in a time-division manner.

P■1-4 and CTl-1-Cr2-2 Off I)
7 The 16 long sword signals connected to the Kusuno contacts are inputted in a time-sharing manner. Key II OI+, lII, l
"2" and "3'' are when only CTl-1 is set, and the key is "4".

5","6"l"? "When only HCTl-2 (7) is set, keys "8-"9", "I
NTERtJPT-”RECALL” ld Cr2-
When only 1 is set, press the key "MULTI '"
.

"SENGLE"°, CIJAR'", the switch that turns on when a jam occurs (jam reset switch) is Cr2
When only -2 is set, "Cassette up/down switching switch f", "AUTO", "C0INCID"
ENCE" and "5IZE" are read when only the ON signal (2) of the exposure lamp, etc. is set. The diode 19 is provided to prevent backflow.

OMS 1 whose peripheral circuits are shown in Figures 6-2 to 6-4
a,! 9 and 21 are for determining the cassette size of the upper cassette, and Ms15 is for confirming its insertion. They output o and 1 signals with weights of 1.2 and 4.8 respectively. MS12゜20.22 is for determining the lower cassette size, and MS 16 is for checking its insertion. They have a weight of 1°2.4.8.And these are MOLT IPLE)σ;R60
9, and switching between the upper and lower stages is done using an l chip.
A code of 1.2°4.8 is output to the outside by the switching signal UL from the microcomputer. Then, the decoder 11 decodes this 1, 2, 4:8. When it is A3, only MS t 5 is turned on, the decoded result becomes 0, and the lamp of A3 is turned on via the driver 612. Similarly, A4 is 1. Ul is 2° and U2 is 3. B4 is 4
．． B5 is 5 or 8 when no cassette is inserted.

Also, if the cassette is not inserted deep enough, the MS
Since 15 or 16 is not ONL, the weight of 8 is always 1, so the decoded result will be any value between 9 and 15, and none of the lamps will light up. (Refer to Figure 6-5) The "5IZE" signal has a weight of 0 in the decoder 611.
This signal which inputs °2.4 to the ORGATE 613 and outputs °1 when one of them is selected, that is, when it is full size, is an input signal that changes the 7-case timing according to the size.

Also, MS13, 19, 21, l! :MS12,20.
2217) 2 sets are MAGNITUDE COMPAJ
When the two weights match, the C0INCIDENCE" signal is set to 1, and it is determined whether the sizes of the upper and lower cassettes match.

1 when commanding the upper cassette (upper/lower switch is on)
The cassette selection signal UL output from the chip microcomputer becomes O.

Therefore, the transistor 621 is turned off, the upper cassette paper detection circuit is selected, and the transistor 622 is turned off.
Since the signal is turned ON via the ERTER 23, the lower cassette paper detection circuit is not selected. However, in the selected upper cassette paper detection circuit, when the paper runs out, CdS 61
The resistance of 5 decreases, and the NEGAT I of operational amplifier 13
VE input terminal 6 is lower than terminal 5, so OPAMP
The output of 613 becomes 'l', which is the 5TOP signal.Similarly, when UL=1, the lower cassette paper detection circuit is selected and functions in the same way.

Further, when the "5TOP" key on the operation unit is pressed while the main motor is driving, FLIP-FLOP 617 is set since A=1, and KSTOP=1. Therefore, when the main motor is not driving, A=O, so it is not set, and when the main motor is driving, FLIP-FLO is set.
P617 becomes A=O and is reset when the main motor stops. This FL 1. The output KSTOP of the P-FIOP 617, the upper cassette paper detection signal, the lower cassette paper detection signal, and the cassette no signal are input to the OR gate 618, and when any of these signals is l'', it outputs 1p as 5TOP'''.

(Explanation of the flowchart of the sequence program stored in the ROM) In order to temporarily store various operation modes when controlling the sequence with a 1-chip micro combinator,
Each bit in the RAM is set and reset, and these are called flags, and there are about 20 types of flags.

Flag i: Set when the 5INGLE key is pressed and reset when the MULTI key is pressed.

Flag 2: As a result of determining the paper size, FULL 5
Set when IZE and reset when HALF 5IZE.

Flag 3: SET C0TJNT and C0PYC
Set when 0UNT matches.

Flag 4: Set when a delay jam occurs.

Flag 5: During MIJLTI-COPY, when entering the second copy cycle from the first cycle, set at the rising edge υ of the second paper feed signal.

Flag 6:■ At the time of Le TI-C0PY, 2
Set at the start of the optical system of the second cycle.

Flag 7: K MULTI or 5 during post-rotation cycle
Set when the INGLE key is pressed.

Flag 8: Set when a jam occurs.

(When paper is stopped on the detector, etc.) Flag 9: When the power is turned on, when the drum is not at H, P (stop position), it becomes cent, H, P and reset when it enters the post-rotation cycle. .

Also, set when the '5INOLE' key is pressed during the post-rotation cycle, and reset when the 'MULT I' key is pressed. FlaglO: Set when the number of input pulses does not reach the set value, reset when it does. do.

Flagll: When entering post-rotation in the copy cycle of HALF 5IZE, set when the optical system becomes H, P while the drum rotates 150° from the inverted position of the optical system, and return to the position 150° from the above. Reset when.

Flag13: Set when CTl-1 is set,
Reset when resetting.

Flag14: Set when CTl-2 is set,
Reset when resetting.

Flag15: Set when Cr2-1 is set,
Reset when resetting.

Flag16: Set when Cr2-2 is set,
Reset when resetting.

Flag17: reset when in the upper row, s when in the lower row
et. For example, if you specify "upper row" with "AUTO",
If you run out of paper, set Flag 17 if the lower cassette is the same size and has paper,
Feed paper from the bottom.

F"lag18: Set when the "INTERRUPT" key is pressed, and reset when the "RgCALL" key is pressed.

Flag19: Cents when the "jam killing 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 or not each of the above flags is set, 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, and is designed to eliminate unnecessary processing operations during testing. The timing charts in FIGS. 3 and 4 and the specifications of the operating section are satisfied. RO of 1-chip microcomputer
System flowcharts of the sequence program stored in M are shown in Figures 5-1 to 5-7.

This system flowchart will be explained according to each step.

In 1.2.3, in order to select the transfer paper size lamp on the operation unit and detect the presence or absence of cassette paper, set or reset the UL according to the instructions from the upper and lower selection buttons.

4, 5 UBP is a display digit signal switching subroutine whose details are described in steps 261 to 284. This 5UB
P is for sequence control. This 5 UBP is always passed in the flow while counting CP or when changing another input signal on the whole program. As a result, the display can be used by switching the display to the normal mode at about 1/4 of the duty (usage rate), and therefore the display can be displayed apparently continuously without flickering.

4-5 If the optical system is not at the home position HP when the power is turned on
- Repeat step 6 to move the optical system backwards, and when it reaches OHP, step 7
to stop reversing. Next, if the drum is not at the home position, steps 8-9-10 are repeated to search for DHP, and when DHP is detected, steps 11-12-52-53 to 62 are performed. 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. This is provided to prevent chattering of the detection signal caused by the microswitch that makes one more rotation after detecting the DHP at 55-56 and detects the next DHP at 5B-59. The relationship between this timing and the flowchart is shown in Figure 8. write down When the optical system or drum is not in H, P, the display only shows 00 o o''. When the optical system is not in H, P
It is not until the drum reaches H and P after making one rotation or more that input using the numeric keypad (FIG. 2) is possible. If the power is turned on, OHP.

If both DHP is detected, 4-5-7-(3-9
-11, and immediately enters the key reading routine of 13-14-15-16.

Figure 3 shows the timing chart for two half-size copies.
We will explain the flow when 2 is entered in the display 25 (number of sheets set) in the figure and the "MULTi" key is pressed.
Enter the sequence routine below 19. 19 indicates the point ■ in FIG. 20.21 indicates the section (■) in FIG. 3, and indicates that the input clock pulses are counted up to 60. Also, in this section, the digit signals of the display are switched sequentially through 5UBP, apparently indicating that the two displays are being lit in parallel with the sequence control.

22 indicates that J (transformer switching) is turned on when CP is counted 60 times. This increases the AC corona discharge voltage. 23.24 refers to the section marked ■ in Fig. 3, and the rule waits for the +1 signal power ipF power ball to be input.
It's Chin.

When reaching point ■ in Figure 3-2, 5 TOPs have been reached before this point.
When the mode is set, the timing diagram shown in (■) in Figure 3-2 will be shown. Therefore, in step 25 in FIG. 5-1, this is determined and the IJIK off step 51 is hejumped.

In addition, 51 represents ■, 52 to 56 represents the period of ■, 57 to 59 represents the period of ■, 6o represents the time of ■, 61 represents the period of ■, and 6
2 indicates the point of ■. Therefore, an emergency stop immediately after the start is possible without losing paper, and the delayed turning off of the lamp prevents uneven charge removal on the drum. if,
If the 5TOP mode is not reached until point (2), the process advances to paper feed B 26 and beyond. 26 indicates ■ and the section from 27 to 3o■, and waits for detection of DHP omission due to drum rotation. 3
1 to 36 indicate the section (■) and wait for the PF to exit. 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 coming out. 37 indicates the point of ■. Since the next step is executed only after determining whether the DHP or PF is missing, reliability can be increased. Also, at this time, 2 indicated by 38 to 45
A check is made for the accumulated jam after the 1st C0PY cycle, but since this is the 1st sheet, it is determined at 38 that Flag 6 is not set, and the process jumps to 46 and beyond. 46～
49 indicates the section of ■, and at the time of ■ (at 31, the number of pulses is 6)
This is the section in which the count is waited for when the CP, whose count is started from 7 (set to 7), reaches the set value of 67.

The time point reached is 50, that is, the time point ■ 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.
In the case of half size, G is ON only during the first copy cycle, and there is no ONL after the second copy, so at this point it is necessary to determine whether it is half or full (65) and whether it is the first copy cycle. Since determination (63) must be performed, this is shown in 63-66. Since this is the first card of the half, I jump to 63-66 and turn on the G as well. 87-count CP counting is started again from point (2). OHP on the way
The routine for waiting for the switch to turn off is 67 to 7o, which refers to the section (■) in FIG. The point in time when Of(P becomes O, F' F is 71, which indicates O in FIG. 3. Therefore, since the next step is proceeded only after determining the omission of the OHP, the precision of the sequence is high.

Also, at this point, a delay jam check is performed in the case of a half ``MULTi'' copy.
After entering the cycle, a paper jam check is performed for the previous copy cycle, so since it is the first copy cycle, it is ignored due to the determination of Flag 6 of 73.
Jump to 2-73-81. This half delayed jam check is indicated by 72-80. In addition, since the blank lamp is kept on until the point O, it is possible to eliminate potential unevenness in the unexposed area when the exposure lamp starts up.

81 to 82 is an interval for waiting for the count to reach 87, which corresponds to the interval ``■'' in FIG. Furthermore, 105 counts from here are 84 to 85, indicating the section (■). The time point when 105 counts are reached is shown as 86 to 101 and 112, which is the time point of the half-size reversal 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. (8
6) To determine whether to switch to another cassette when the paper runs out, determine whether it is set to AUTO (87), and determine whether the cassette size is the same (88).
)There must be. 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 determination of 5TOP in 86 also includes cases in which the 5TOP key is pressed or 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 5TOP is returned again in 101. is determined, so it is returned to the original state again when it advances to the post-rotation after 112 and returns to 13 of the key reading routine.
no problem.

Furthermore, since the point of ■ is the inversion position of the optical system of No.-7 size, it is determined at 92 whether it is half or full, and if it is full, the process passes through 93 and proceeds to 190 onwards in Figure 5-4, but for now Since this is a half case, proceed from 94 onwards. And 96-1
At 02, the copy count (CT2+1) is completed and compared with the set number CT, and if the two match, 5
When the TOP mode is entered, if a jam occurs before the time point (3) in FIG. 3, the process proceeds to the post-rotation routine from 112 onwards. If the above is not the case, go to the routines 103-111. This routine is executed if the 5TOP mode is entered within the time when the paper feed PF multiplication signal is input from the reverse position of ■ (3rd
At the timing 3 in the figure), the transformer switching J is set to 0FFL, and (106) is 150 cou.
It waits until it reaches nt and jumps to the post-rotation routine from 134 onwards. The flow of this time 103-104-105-106-
It becomes 107-109-103-104-134. If the 5TOP mode does not occur, 103-104-105- until the PF turns on (section ■ in Figure 3).
10'l-109-103...repeat, P'F is ON
When it became 1103-104-105-108Fl
Cut a 5, (C0pycycle from second time onwards)
The process returns to the point in time when the paper feed roller control signal B of 26 is turned ON again. This refers to the time point (■) in FIG. 3, but from this point onwards, the same control contents as in (1) to (4) in FIG. 3 are basically repeated.

However, since the optical system reverse (F) stop and delayed jam check are included in CopyCyCle for the second and subsequent copies, only this will be additionally explained.

2nd time 32-36, DHP goes OFI and then PF goes O.
The time required until the FF is turned off is shown (section 2 in FIG. 3). If the optical system reaches OHP within this time, the F is turned off after passing through 35-36.

Since the backward movement of the optical system and the rotation of the drum motor are asynchronous,
There is some irregularity in the time the optical system reaches OHP.
-49) are provided with routines (29-30° and 48-49) for detecting OHP and turning off F.

Delayed jam check on the first sheet of paper is a copy of the second sheet.
In cycle K, the optical system moves forward (Eon) and O
This is done by detecting the arrival of paper to the detector 2 when the HP is OI"F L, so it refers to the time point ■ in Fig. 3. This is checked in the routine from 72 to 8o in Fig. 5-2. .71-73-74-75- if the paper is not detected after a delay.
Pass through 7 rows 77-78-79-80, set Flag 4, memorize the delay jam, and ca.
l))' Subtract one sheet from the count CT2 and remove the jam.
Turn on solenoid I'cONi. If the jam killer switch turns on/off, that instruction is the key
If read by utine 13, 77 to 8o will be ignored. The activated ■ is turned off at the time of 83 (3rd
- At the point marked ■ in Figure 2. ) Therefore, you can test run the machine without feeding paper. Also, although Fig. 3 only shows the timing diagram for the case of two-sheet copying, if this is three or more sheets of copying, the first sheet of paper should be checked for accumulated jam (detector engineer's paper stoppage check). ) is performed when the PF is turned off in the third copy cycle. This is 38
-45. If the first copy has a jam, 38-39-40-42-43-45
The process passes through 135 and enters the post-rotation routine. At this time Fl
Set ag 8 and remember that there was a retention jam.Furthermore, when it is half, the copying cycle for the third copy has already started, so the copy count CT2 is subtracted by 12. However, if it does not stay, the process proceeds 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, the delay jam check at ■ is completed, and the second copy cycle is also performed at the optical system inversion position ■.
Suppose we reach the point.

At this point, the number of sheets set at 99 and the number of sheets counted match, so Flag 3 is set at 102, the fact that the mode ends due to the match is memorized, and the post-rotation routine starts at 112 and thereafter. 113 to 133 indicate the section marked ■ in Figure 3,
While counting cp for 150 counts, in parallel, wait for the optical system to reach 0 HPK within that time, and when it reaches 0HPK, turn OFF F (115-116) and at the same time check the accumulated jam of the first paper of vc. (117-126
5UBI) and set Flagll.

Once this is set, from now on, even if the optical system is in OHP, the jam check routine 11 will be executed at 117.
8-125 are ignored. This time point refers to the time point ■ in FIG. Therefore, the jam check during post-rotation is performed only when the optical system reaches OHP. If a delayed jam has not occurred before this point, and no instruction to kill the jam has been given, and the first sheet of paper is jammed, 117-118-11'J-120- 1
21-123-124-125-126, Fla
Set g 8, memorize the fact that there was a retention jam, subtract -2 from the number of copies since it is half size, and turn on the jamn V nod ■. (Fig. 3■), then Flag
Since 11 is set, jump to 117-127. However, if there is no stagnation when the optical system reaches OHP, 117-118-119-120-
Proceed to 122-126 and set the TC of the total counter signal to O.
Let N. On the other hand, within the time to count this CP to 150, 127 to 133 start key person car routines 5UBH
This is because the number of sets and the number of copies match, and the process goes to the post-rotation routine or 5I.
Only when entering the post-rotation routine in NGIJ mode, the MULTI or 5INGLE key is accepted again from the time point ■ in Figure 3-2, so the routine that reads these is 0, for example, when the MULTI key is pressed. In case 127-128-129-130-1
33 and 127 if the 5INGLE key is pressed.
Pass through -128-129-131-132-133. Therefore, when pressing the MTJ L T I key, set FIag 9 to 0. FIag7el, when 5INOLE key, FIag7el
Set ag 9 to 1° FIag 7 to 1. FIag 9
is for determining whether it is MULTI or 5INGLE, FIag
7 is used to remember that a restart command was entered during the rear rotation. When the CP count reaches 150, it is 134, which indicates the point in Figure 3 ■. 135, 136, and 137 are provided for safety because the point at which the optical system reaches Oi (P) varies.138-140 indicates the section (■) in Fig. 3-3, and counts 38 counts from the point where CP is 0. The time when the count reaches 38 is the point ■ in Figure 3-3, and in this case, the I turned on during the retention check at the point ■.
Or turn off the TC (141) and set the last 0
This is also the time to perform a late jam check for 097 paper. The flow at this point is shown in 142 to 149, and a jam check is performed if no stagnation or delayed jam has occurred before this point and there is no command to kill the jam. If jamming, turn ■ ON L, Fla
g Set 4 and subtract 1 from copycount 0
However, in the case of 1SINGLE mode, this subtraction is ignored.

(147). 150 to 152 indicate section 9 in FIG. 3-3, and 60 CPs are counted.

Then, when this value is reached at 153, when the jam check is turned on, the check mark 2 is turned off. In Figure 3-3, ■
refers to the point in time. 154 to 156 are the waiting times for reaching 0HPVC, which corresponds to the section (■) in FIG. And 3-3
In the figure, MULT I, SI in the section from ■ to ■
140,152,1 to accept NGLE key
56 is provided with 5UBH. When 0) IP is reached (00 in Figure 3), the motor on signal A is 157.
Turn off. 158 indicates the section ■, and 159 indicates the time point ■. If a delay or accumulated jam occurs before this, the jam clearing routine from 160-161 to 182 onwards is entered. If this is not the case and there is no command to kill the jam (162), the last 0097 paper is checked for remaining jam. If the retention check is OK, T Ci ON, OFF at 164, 165, 166
However, if the number of sets and the number of copies match and the end mode is entered, clear the number of copies with 167 and -168, and further,
If the MULTI or 5INGLE key is not pressed during the post-rotation, the process passes through steps 169-175 and returns to the key reading routine in step 13.

16 if the MUL'TI key is pressed
It passes through 9-170-171, and at 173 it is determined whether the set number is 0. If it is 0, it passes through 175 and enters the key reading routine at 13, and the MULTI key being rotated after 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 5INOLE key is pressed, 1717170-172-17
Pass through 4 and jump to 19 and copy again in 5INGLE mode
Enter cycle.

In the above-mentioned stagnation check, if stagnation occurs, turn ON, 0
FFL, , copy number - 1 subtraction. 163-176-1
77-178-179-180-181). However, 5iN
If it comes in GLE mode, -1 is not subtracted.

182 to 189 are jam release routines, 6N and O of ■
The routines 182 to 184 are waiting for the jam switch turned on by the jam mechanism (shown in Figure 9-2) latched by the FF to be released (reset button turned on).
When 0 is released and turned OFF, proceed to 185 and after, and here the MUL pressed before entering the copy cycle is
M'U for MULTI for TI or 5iNGLE
Wait for 5iNGLE to be pressed for LTI and 5iNGLE. Therefore, if MULTI has been pressed previously, the process passes through 185-186-187-188 and goes to 19 to copy the remaining number of copies. S 1NGLE
For that, it goes through 185-186-187-189 and also jumps to 19. Therefore, other combinations are not accepted.

Next, the flows shown in FIGS. 5-4 and 5-5 will be explained with reference to the full-size timing chart shown in FIG. 4-2 go through the same flow as the flow up to that point in FIG. 3, so the explanation will be omitted. Therefore, this time point (■) is the inversion position of the optical system for the No. 1-F size, but since this time it is a full size, the point from here on is different from the No. 1-F.

Therefore, ``■'' refers to flows 86 to 92, but when the size is determined in 92, the process passes through 93 and jumps to 190 and thereafter. 190-191 is a routine that waits for the vehicle to advance further along the prefectural road from the half-size optical system inversion position and count CP by 150, and refers to the section (■) in FIG. 4-2. and 150
The point at which the count is reached is the optical system inversion position of FULL 5IZE (point 2 in FIG. 4). 192 in flow
~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. 19 because it is inverted position
At 2, turn E and G 0FFL, and turn F and L ON. Furthermore, MUL
In TI mode 193, if no jam has occurred before this point (194, 195), increase the copy count by 1 at 196.
If it is added and it matches the 5ETCOUNT number, 197 proceeds to 232 via 199-231. If there is no match and the 5TOP mode is selected, the process jumps to 232 via 231. Therefore, only when there is no match and the mode is not 5TOP mode, the process proceeds to 200 and thereafter. Therefore, at this point (■), there are two routes: one for proceeding to 200 and beyond, and one for proceeding to 231 and thereafter. First, the flow after 231 will be explained. A case that goes into this flow is 5INGL
When in E mode (193).

When a jam occurred previously (194, 195).

This is either when the set count and copy count match (197°199), or when they do not match and the mode is 5TOP mode (197, 198), and the point 0 in Figure 4 appears to be ■ It can be considered that the situation has moved to the point of . Therefore, since the current copy count is the first one, it can be considered that the sequence moves from O to ■ only when the 5TOP mode is reached 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 marked ■ in FIG. 4-2, and the point in time when 38 counts of Cp is counted is indicated by the mark ■ in FIG. 4. At this point, a delay jam check for copy paper is performed, and the check flow is shown in 202-208. This jam check is a jam killing command (203)
It is effective when there is no copy paper, and if the copy paper is delayed, Fl
Set ag 4, turn on jam solenoid T, subtract -1 from copycount, and turn tJ off. This timing diagram is shown at 2 in FIG. Further, this subtraction of the copy count is ignored in the 5inGLE mode (206). Next, the time to count 112 cps indicated by 209 and 210 is shown in Figure 4.
indicates the interval.

The point in time when 112 counts are reached is indicated by ■ in FIG. At the time of this ■, the I that was turned ON at the time of the above ■ is turned OFF.
At the same time as F, it is determined whether a delayed jam has occurred (212) at the time of ■. If a jam occurs,
As a result of the determination at 212, the process proceeds to 213 and subsequent steps to satisfy the timing 2 in FIG. First, at point (■), K is turned off (214).

At steps 214 and 215, wait until the optical system reaches OHP.

This section refers to the section marked ■ in Fig. 4. The time when OHP is reached is indicated by ■ in Figure 4, F is turned OFF, and (216)
, 217, and 218 (section (■) in Fig. 4) When reaching DHP L, wait for the DHP to turn off at 220 and 221 (section (■) in Fig. 4). D
If the HP goes off, jump to 154 or later and wait for the DHP to come again (section ■ in Figure 4) + 0 to end the copy operation.
12).

If it is OK, wait at 223 and 224 for the OHP to arrive (section ■ in Figure 4), then turn OFF F at 225 (■ in Figure 4) and wait for the PF signal to arrive at 226. ,2
Wait at 27 (section ■ in Figure 4).

The time point when the PF is reached is the time point ■ in Figure 4. If the 5TOP mode trap is reached at this point, the 5TOP is determined at 228 in 70- to satisfy the timing 3 in Figure 4, and from 222 onwards. move on. Turn off J and K at 229, wait for PF to turn off at 257-260, search for DHP that will arrive after the next rotation, and stop the copy cycle.

If it is not 5TOP mode, set Flag5゜6 at 230.
5et(,,To enter the second copy cycle, 2
Jump to 6. Therefore, ■~■ in Figure 4-3 corresponds to ω~■ in Figure 3.
It follows the same flow. However, at point (■) of the copy cycle for the second and subsequent sheets, the first sheet of copy paper is checked for accumulated jams, so the check and flow are 38 to 4.
5.

If it stays, it passes through steps 38-39-40-42-43-44 and jumps to 217 to satisfy timing 4 in FIG. First, when it stays, turn off J and K, and set the Flag
Set 8 and subtract -1 from the number of copies. Thereafter, the process jumps to 217 and the drum is rotated until the DHP force amount is detected, and then the copying is completed.

In the copy cycle for the second full-size copy, ■～■ is・
・Execute 70-, which is the same as for the -7 size, and the point at which both branches branch is at point ■. 92 of the flow is the reversal position of ...-). Therefore, the section O in FIG.
From 0 to 1920 hours, the point ■ is the reversal position of the 7le size, and the number of copies matches the number of cents at 196, so 1
92-193-194-195-196-197-19
9-231, turn J to 0FF (-th order charging off),
The process proceeds to the post-rotation routine after 232.

232-234 is the time to count 38 cps,
The section marked ■ in FIG. 4 is shown. 38 counts (4th
■) in the figure is where the last paper is checked for a late jam, and is shown in steps 235 to 241 in the flow. Here, even if no accumulated jam has occurred before (235), a jam occurs when there is no force/jam kill command (236).

If a check is made and there is a jam, the jam solenoid I is turned on and the copy count is subtracted by -1. However, 5i
When in NGLE mode, subtract the number of copies (240
) shall not be carried out. 242 to 244 refer to the section (■) in FIG. 4, which is the time when the cp is 60 counts. When this count was reached, it turned ON at 241 mentioned above■
(■ in Figure 4). Furthermore, at 246-248, I counted 52 cps (■ in Figure 4), and at 249 I counted CP (■).
Turn off IAS K (■ in Figure 4).

Wait for the optical system to reach the OHP at 250-252 (section 2 in Figure 4), and turn off F at 253 (2 in Figure 4)'. After that, 254 to 256 (■ in Figure 4)
Wait for the paper feed cam pF to turn ON at 258 to 260 until it turns OFF. And OFF
When this happens, the drum rotates one more time and waits until it reaches the DHP (154 to 156. (■) in FIG. 4), and then ends the copy cycle.

In addition, 23/I, 2,11I, 248, 252
, 256, and 260, the subroutine 5UBH is placed in the loop, and the MULT is
This is provided so that the I or 5iNGLE key can be read.

Also, the "INTERUPT" key has the same function as the "5TOP" key, and similarly shifts to the post-rotation mode. Moreover, at this time, the number of sets on the indicators 25 and 26,
The count number is moved to a set of registers in memory RAM, and a new value can be entered on the display. After this, execute the flow from the key entry above. When copying is completed and the post-rotation mode is entered "RECA LL"
``When you press the key, the original value stored in the register above in RAM is transferred to the display 25, 26 and displayed again as ``MULT.''
You can copy the remaining number of copies by pressing the "I" key.

Figure 9 shows devices related to jam safety. Figure 9-1 shows a door switch for safety when handling jammed paper, and is used to open and close the national cover and door. The state of the microswitch DS that turns the power on and off accordingly is illustrated.

Figure 9-2 is a fixing device using jamunrenoid.

A mechanism for turning off DC high voltage power is shown.

When a jam occurs, the lunoid SL is actuated to pull up the lever 92 with the dowel 91 attached, and the release leno<-93, which was fixed by the dowel K, 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.

Table 1 shows an example of a program code list of command words and the like for executing the programs shown in FIGS. 5-1 to 5-7 in accordance with the PPS-4/I manual.

Table 1 Program steps

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a copying apparatus to which the present invention can be applied, FIG. 2 is a plan view of the operating section of the apparatus shown in FIG. 1, and FIGS. 3-1 to 3-1.
Figures 3-3 are half-size operation time charts for the device in Figure 1. Figures 4-1 to 4-3 are full-size operation time charts, and Figures 5-1 to 5.
Figure-7 is a control flowchart of the device in Figure 1, and Figure 6-1.
6-5 are examples of the control circuit according to the present invention, FIG. 7 is the internal circuit of the computer used in FIG. 6, FIG. 8 is a control time chart when the power is turned on, FIG. 9-1, 9-2
The figure is a sectional view of the safety device and jam release device in each of the devices shown in FIG. 1. In FIG. 6-1, CPU is a computer chip element, G is an output gate circuit, M is an input matrix circuit, and is a display, pH~4 is an input terminal, G is a scanning output terminal, and Dl is a load output terminal. Procedural amendment (voluntary) Kazuo Wakasugi, Commissioner of the Patent Office1, Indication of the case, Patent Application No. 40952 of 19822, Name of the invention Image forming device3, Person making the amendment Relationship to the case Address of the patent applicant 3-30-2 Shimomaruko, Ota-ku, Tokyo Name (+00
)Representative of Canon Co., Ltd. Ryu Kaku Part 4, Agent Address 3-30-25 Shimomaruko, Ota-ku, Tokyo 146 Description subject to amendment d Contents of amendment (1) The scope of claims of the specification should be attached to the attached document. Correct as shown. (2) Add the following after "Regarding." in line 10 of the first page. ``Conventionally, it is known that during repeated copying operations for a set number of copies, if an accident such as a sheet jam occurs, copying is interrupted and the copy count up to that point is retained.However, in this case, sheets are lost due to jamming. Therefore, when restarting after a jam, the number of sheets will be insufficient if the count is restarted from the count number at the time of interruption.To solve this problem, a method that corrects the number of sheets is known. It has a counter that detects and counts it,
Normally, the number of exposure counters is displayed, and when a jam occurs, the number of discharge counters is replaced with the contents of the former counter.
This ensures that there is no shortage of loss upon completion of copying. However, this requires multiple counters that count together during the copying operation, making the circuit configuration complex and increasing costs.The present invention eliminates the above drawbacks and corrects the number of sheets using logical operations. an input means for setting a desired number of image formations, a means for returning to school without performing the number of image formations set by the input means, and a memory for counting and storing a number related to the number of image formations according to the progress of the image formation operations. an image forming apparatus comprising: means for detecting a trouble during image forming operation; means for interrupting the image forming operation by the detecting means; and means for calculating and correcting the number of memories stored in the memory by a predetermined number after detecting the trouble. be. November 29, 1980 Manabu Shiga, Director General of the Patent Office, Patent Application No. 40952 (1982) 2, Title of Invention Image Forming Device 3, Person Making Amendment Case Relationship with Patent applicant address 3-30-2 Shimomaruko, Ota-ku, Tokyo Name (+00
) Canon Co., Ltd. Representative Ryu Kaku 3 Department 4, Agent Address: 14ft Canon Co., Ltd., 3-30-2 Shimomaruko, Ota-ku, Tokyo (Telephone: 758-2111) 1988
October 30th (shipment date) 6. Specifications and drawings subject to amendment

Claims (1)

[Claims] An image forming apparatus comprising means for forming an image on a sheet, means for counting and storing the number of times of image formation, means for detecting trouble, and means for correcting the number of times of image formation according to the location of the trouble after detecting the trouble.