JPH028309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for eliminating the optical memory effect of a photoreceptor when the photoreceptor is exposed to external light in an electrophotographic copying machine configured to be separable into upper and lower parts. be.

According to electrophotographic copying machines, images may gradually become thinner due to fatigue of the photoreceptor. In other words, due to fatigue of the photoreceptor, the image density differs between the first and second sheets, and the image density becomes stable after the third sheet. Therefore, when copying is performed, prior to image formation by the start of copying, the photoreceptor is rotated idly to charge and remove electricity, and after the photoreceptor is fatigued to a stable state, image formation is started. For example, Japanese Patent Application Laid-Open No. 54-105553 discloses that in an apparatus for forming an image on a photoreceptor, prior to image formation, a pretreatment process is performed in which the photoreceptor is rotated to fatigue the photoreceptor to a predetermined state. , it is specified that image formation is initiated.

Furthermore, in the electrophotographic copying machine as mentioned above,
When copying paper is jammed, when cleaning areas contaminated with developer, when replacing or repairing the photoconductor or other consumable parts, open the front door of the copying machine and reach inside. , had to be treated. Alternatively, it has sometimes been necessary to remove the rear or upper exterior, and sometimes even unrelated parts within the main body. So recently,
A copying machine has appeared in which the main body can be separated vertically from one end along the copying machine feeding path, making it possible to considerably alleviate the above-mentioned difficulties.

However, since separation is possible in this manner, the photoreceptor is exposed to external light during separation, resulting in a large change in the characteristics of the portion of the photoreceptor exposed to the light. Therefore, when the separated upper and lower parts of the copying machine main body are closed again and a copy is made, an optical memory effect occurs, causing problems. For example, because not enough charge is placed on the photoconductor, the first few copies may appear white, especially in areas corresponding to the photoconductor parts exposed to external light, or the colors of the formed images may be pale. There will be negative effects such as

In particular, when a user encounters a paper jam, separates the top and bottom of such a copying machine, removes the jammed paper, closes it again, and makes a copy, it is difficult for the user to receive blank copy paper. This would be extremely inconvenient. Therefore, even if image formation is performed after performing preprocessing prior to starting copying, as specified in the conventionally known Japanese Patent Application Laid-open No. 54-105553 mentioned above, the optical memory Due to this effect, normal image formation cannot be obtained.

The present invention has been made in view of the above drawbacks,
The main body of the copying machine is made separable along the conveyance path of the copy paper, detects when the top and bottom separation operation changes from the open state to the closed state, and when the power to the copying machine is turned on in response to this detection signal, Driving an optical memory removal means formed by driving a part of an image forming means that rotates a photoreceptor and repeatedly forms images on the photoreceptor;
To provide an optical memory removal device which removes the optical memory of a photoreceptor caused by a separating operation and maintains the same copy quality as the copy before the separation from the first copy after the separation.

As mentioned above, the photoreceptor is exposed to external light mainly when there is a paper jam or when the upper and lower parts of the main body are separated and opened for maintenance. Therefore, the optical memory removing means may be energized in conjunction with the detection of closing after separation and opening. When separating the upper and lower parts of a copying machine, the power supply to the main parts inside the copying machine is generally stopped for safety reasons. Therefore, according to the present invention, when the vertical separation of the copying machine main body is detected, the removal means for removing the optical memory is driven when power is resupplied to the copying machine main body. In particular, the power switch is connected in series with a door switch, etc. for opening the main body of the copying machine vertically. Therefore, the door switch is opened in connection with the vertical separation, and in response, some parts are opened for safety. The power supply will be cut off.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a sectional view schematically showing a copying paper according to the present invention, and FIG. 2 is an external view showing a state in which the main body of the copying machine is separated into upper and lower parts. In the figure, reference numeral 1 denotes a drum-shaped photoreceptor that is rotationally driven in the direction of the arrow. On the circumferential surface of the photoreceptor 1, various copying processes for image formation are arranged facing each other. Reference numeral 2 denotes a corona charger for uniformly charging a photoreceptor provided facing around the rotating circumference of the photoreceptor 1, and 3 a corona charger for exposing the uniformly charged surface of the photoreceptor to an image of the document 5 on the document table 4. 6 is an illumination device that illuminates the original 5; 7 is a developing device that visualizes the electrostatic latent image formed on the surface of the photoreceptor 1 as a toner image after image exposure; 8 is a paper feeding and conveying system; A corona charger 10 is used to electrostatically transfer the toner image onto the copy paper 9 sent through the photoconductor 1, a corona charger 10 is used to remove charges remaining on the photoreceptor 1, and 11 is a light emitted from a lamp. It is a static eliminator. In the copying machine shown in FIG. 1, the developing device 7 also serves as a cleaning device to remove toner remaining on the surface of the photoreceptor. or,
12 is a heat fixing roller for fixing the toner image on the copy paper 9, and 13 is a discharge roller for discharging the copy paper 9 after fixing.

In the copying machine shown in FIG. 1, an upper part 15 and a lower part 16 are separated from each other about a support shaft 14 on the paper feed side in order to separate the copy paper 9 into upper and lower parts along the transport path (the part indicated by the dotted line). It has a structure that allows it to rotate against the other direction. Various copying processes provided around the photoreceptor 1 are attached to the upper part 15, and only a corona charger for transfer is attached to the lower part 16 side. In this case, upper and lower rollers of the conveyance system are provided respectively. A spring 17 is attached between the upper part 15 and the lower part 16 of the copying machine main body, and the upper part 15 is connected to the support shaft 14.
It is always urged upwards with the center as the center. Also, the upper part 15
is fixed to the lower part 16 by a locking member 18 provided on the upper part 15 being locked with a locking member (not shown) provided in the lower part 16. In other words,
When the locking member 18 is released, the upper portion 15 is opened by the biasing force of the spring 17 as shown in FIG. At this time, a part of the photoreceptor 1 attached to the upper part 15 is exposed to external light 19, and optical memory is generated in that part.

In addition, 20 in the figure is a detection micro switch for detecting opening/closing of the upper part 15 of the copying machine main body, and when the upper part 15 changes from the closed state to the open state and then to the closed state again, the copying machine is separated into the upper and lower parts. This is to detect when something has happened. This micro switch 20
is attached to the lower part 16 main body side. Further, numeral 21 is a power switch, and 22 is a door switch. The door switch 22 changes from a closed state to an open state when the exterior of the copying machine (not shown) is removed, and detects the state in which the exterior of the copying machine is removed.This allows the power supply to be switched off for safety. Cut off. Moreover, the exterior is removed, for example, when opening the upper part 15.

In the copying machine configured as described above, a specific example of the configuration of the optical memory removing device according to the present invention will next be described in detail. First, the copying operation will be explained. When the copy switch is pressed, the photoreceptor 1 rotates, and as described in JP-A No. 54-105553, the image is formed after the photoreceptor is fatigued to a predetermined state before image formation. and is valid. Therefore, a synchronous disk 23 having a slit for synchronization is provided on the same axis of the photoreceptor 1, and upon receiving a signal from this synchronous disk 23, the copying control circuit performs the following steps.
Various copying processes (image forming means) for repeatedly forming images on the photoreceptor 1 are sequentially controlled. This copying control circuit is conventionally well known and is used to sequentially control a copying machine. First, the corona charger 2 is driven to sequentially and uniformly charge the photoreceptor 1. Then, when the image forming start end of the photoreceptor 1 reaches the exposure start position, the movement of the original platen 4 is started, and at the same time, image exposure is performed on the photoreceptor 1 via the optical system 3. Next, the latent image formed by the image exposure is visualized as a toner image when it reaches the position of the developing device 7, and is transferred onto the copy paper 9 fed through the conveyance system by the action of the transfer corona charger 8. The toner image is transferred. After this transfer, the remaining charge on the photoreceptor 1 is removed by a corona charger 10 for charge removal, and further the charge is optically removed by an optical charge remover 11. Then, when the photoreceptor 1 passes through the corona charger 2, it is not corona charged and reaches the developing device 7 without being image exposed, and the residual toner is removed and the photoreceptor 1 is ready for the next image formation. In other words, one copy is made by the photoreceptor 1 rotating twice.

On the other hand, the copy paper on which the toner image has been transferred is peeled off from the photoreceptor 1, passes through a heat fixing roller 12, is fixed, and is discharged from the copying machine via a paper discharge roller 13.

During the copying operation described above, if the copy paper 9 gets jammed in the conveyance path, the upper part 15 of the copying machine body is
Release the jammed paper to open it from the lower part 16 and remove the jammed paper. In this case, since the copying machine main body upper part 15 is separated along the conveyance system, it can be easily removed. After this removal, the upper part 15 of the copying machine is closed to the lower part 16. In this case, when the upper part 15 is opened, the photoreceptor 1
A portion 1a is irradiated with external light 19, and the optical memory effect acts on this portion. In order to remove this optical memory, it is necessary to separate the top and bottom of the copying machine body.
The optical memory removal means is driven in response to the detection operation by the detection switch 20 that detects changes from the closed state to the open state and the open state.

Next, the optical memory removal device will be described in detail. FIG. 3 is a diagram showing a specific example of the drive circuit of the optical memory removal device. The apparatus of the present invention drives each copying process to remove the optical memory. In other words, the synchronizing disk 23 is used, and each copying process described above is driven by signals from the disk 23. Synchronous disk 23
As shown in FIG. 4, seven slits Pa- ₀ to _Pa-6 are formed, and the slits are detected by a detector consisting of a light emitting diode 24 and a phototransistor 25. Note that the synchronous disk 23 is shown without the slit for copying.

In the synchronization disk 23, the position of the slit Pa- ₀ is the start position (standby position) of the photoreceptor 1. The leading edge of the photoreceptor at which image formation starts is determined in correspondence with this start position. In the circuit diagram of Figure 3, the photo
The emitter output of the transistor 25 is a one-shot multivibrator (hereinafter referred to as MB) 26.
It is also supplied to one input terminal of the AND gate 27. The other input terminal of the AND gate 27 is supplied with the output of the MB 26 . MB26 is the slit signal from the synchronous disk 23
When PA is input, the output is "H" for a certain period of time, and this time T is a time slightly longer than the period t during which the slit signal PA- ₆ is output due to the rotation of the disk 23 and the slit signal PA- ₀ is output. It is set to . That is, the slits Pa- ₆ and Pa- ₀ are spaced close to each other, and the starting position of the photoreceptor 1 is detected. Therefore, while the output of MB26 is H, the slit Pa- ₀
When the signal PA- ₀ is detected, the AND gate 27 opens and outputs the signal SPS indicating the initial position of the photoreceptor via the inverter 28.

The flip-flop 29 is connected to the reset terminal R side of the flip-flop 29 via a series circuit including a close detection switch 20, a resistor R, and the like to a DC power supply +V whose supply is interrupted by opening and closing of the power switch 21. Further, one end of the resistor R is grounded via a capacitor C.

Then, the power switch 21 and the door switch 22
If either of the detection switches 20 and 20 is opened and the resistor R is left without power +V, an internal resistance (not shown) between the reset terminal of the flip-flop 29 and ground causes the capacitor to close. The charge accumulated in C is discharged, and the voltage at the reset terminal of flip-flop 29 becomes "L". Then, when the power switch 21, door switch 22, and detection switch 20 are all closed, power +V is supplied to the circuit of the resistor and capacitor C, and the voltage between the terminals of the capacitor gradually shifts to "H".

Therefore, the set terminal S of flip-flop 29
is supplied with the signal SPS from the inverter 28, and until this signal becomes "L", the set output Q (IRA signal) of the flip-flop 29 is
The "L" state will be maintained. The flip-flop 29 and the following flip-flops are set or reset when an "L" signal is supplied to each input terminal. Also, and gate 2
The output of 7 is supplied to one input terminal of a NAND gate 30, and the other input terminal of this NAND gate 30 receives signals from output terminals A and C of a binary counter (hereinafter referred to as counter) 31. The output of NAND gate 32 is supplied.
The counter 31 is a counter that is reset when the initial reset signal IRA is "L", and counts up by one when the output from the NAND gate 30 is "L". In other words, the counter 31 receives the signal SPS
Count this each time it is output. Therefore, when the counter 31 counts "5", the output terminals A and C become "H", the output of the NAND gate 32 is inverted to "L", and subsequent counting is stopped. The output of the NAND gate 32 is the inverter 3
3 and becomes the signal ISB. This signal ISB is a signal obtained by counting the start position detection signal of the photoreceptor 1 five times, and is used as a stop signal for the optical memory removing means.

On the other hand, the slit detection signal PA is input to the decimal counter 34 and counted. Decimal counter 3
4 includes a decoder, and the decoded output is used as a driving signal for each copying process. Decimal counter 34
is an AND gate 35 with input signals IRA and SPS.
It is reset by a signal from slit signal PA-1, and when it counts six slit signals, it is reset and starts counting from slit signal PA- ₁ .

Signals and signals from the above decimal counter 34
Each copying process is controlled by ISB and IRA. In other words, control is performed to remove the optical memory of the photoreceptor 1. Examples of the drive circuit are shown in FIGS. 5a to 5f. In FIG. 5a, signal ISB is applied to the set input terminal of flip-flop 36, which provides the set output of flip-flop 36 to the base of transistor 37. The emitter of the transistor 37 is grounded, and the collector is connected to the power supply V ₀ via the main motor relay 38.
is supplied. Further, the reset input terminal of the flip-flop 36 is supplied with a signal (slit Pa- ₆ ) from the decimal counter 34 via an amplifier 39 and a differentiating circuit 40. When the signal ISB is "H", the flip-flop 36 is differentiated at the falling edge of the signal, and the reset input terminal becomes "L" and is reset. For example, when the power switch 21 and the door switch 22 are closed and the detection switch 22 is changed from the open state to the closed state, the main motor relay 38 is connected to the flip-flop 36 because the signal ISB is "L".
The Q output of becomes “H” and the transistor 37 becomes “H”.
When the power supply V ₀ is supplied by closing the detection switch 20 to turn on, the contact is closed and the main motor is rotated to rotate the photoreceptor 1 . At this time, the fixing roller 12 and the conveyance system are also rotated at the same time.

Also, in FIG. 5b, the signal from the decimal counter 34 is supplied to the set input terminal of a flip-flop 43 via an inverter 41 and a differentiating circuit 42. The signal is inputted together with the signal ISB to a NAND gate 44, and the output of this NAND gate 44 is supplied to the reset input terminal of the flip-flop 43 through an AND gate 45 which inputs the signal IRA to one input terminal. The set output of flip-flop 43 is supplied to the base of transistor 46, and
It controls the switching of 6. The emitter of the transistor 46 is grounded, and the collector is supplied with the power supply V _AC via the high voltage generating circuit 47 of the corona charger 2.

Similarly, the lamp 50 of the lighting device 6 in FIG.
is driven through transistor 49 which is turned on by the set output of flip-flop 48. The set and reset input terminals of the flip-flop 48 are
Signals, ISB and IRA are supplied via a circuit similar to that shown in FIG. 5b, surrounded by dotted lines.

Furthermore, each of the high voltage generating circuits 53, 56 and the static eliminating lamp 59 of the transfer corona charger 8, the static eliminating corona charger 10, and the optical static eliminating device 11 shown in FIGS. As a result, it is driven through the respective transistors 52, 55, and 58.

In the circuit configuration as described above, the removal operation of the optical memory according to the present invention will be explained with reference to the time chart of FIG. Therefore, after opening the upper part 15 of the copying machine main body due to a paper jam, etc., the upper part 15 is moved to the lower part 16.
When the switch is closed, the detection switch 20 is closed. At this time, power switch 21 and door switch 2
2 is closed, the power supply +V is supplied to the series circuit of resistor and capacitor R and capacitor C, which causes flip-flop 2 to close as described above.
9 is reset, and its set output Q, that is, signal IRA becomes "L". Then, the counter 31 is reset, the signal ISB becomes "L", and the flip-flop 36 is set at the same time. Therefore,
Power V ₀ is supplied to the main motor relay 38,
The main motor rotates to rotate the photoreceptor 1. Due to the rotation of the photoreceptor 1, the synchronous disk 23 is passed through the
A slit signal PA is output and counted by a decimal counter 34. Therefore, the slit signal
The period when Pa− ₆ is output and then Pa− ₀ is output,
Since the “H” signal is output from MB26,
AND gate 27 is opened and flip-flop 29 is set via inverter 28. At this time, the flip-flop 2
9 is set. At this time, the gate 35 is opened by the output of the inverter 28, that is, the signal SPS, and the set output signal IRA of the flip-flop 29, and the decimal counter 34 is reset. In other words, photoreceptor 1
The rotation start position of the photoreceptor is detected, after which the optical memory removal operation of the photoreceptor is performed. This is to search for the start position of the photoreceptor 1 when the photoreceptor 1 is not stopped at the start position due to a paper jam or the like. The signal SPS that detects this start position is counted by the counter 31. As a result, the counter 31 counts "1".

After the above, when the starting position of the photoreceptor is detected, the decimal counter 34 is reset and starts counting the next slit signal. Therefore, when the image forming start tip corresponding to the start position of the photoreceptor 1 faces the corona charger 2 in synchronization with the rotation of the photoreceptor 1, the slit signal PA- ₁ of the disk 23 is output. This causes the decimal counter 34 to count and output a signal. In response to this signal, the flip-flop 43 is set, power source V ₀ is supplied to the high voltage generating circuit 47, and the corona charger 2 uniformly charges the photoreceptor 1 from the leading edge where image formation starts.

Next, when the image forming start end of the photoreceptor 1 reaches the exposure start position, the slit signal PA- ₂ is output, and the flip-flop 48 is set by the signal. Therefore, the exposure lamp 50 is turned on and exposure is performed through the optical system. At this time, the document table 4 is not moved and is stopped at the initial position.
The lower surface 4a of the document table 4 is formed to cause diffuse reflection so that the light from the lamp 50 is irradiated onto the photoreceptor 1. On the other hand, in the same way as described above, each circuit 53, 56, 59 is driven by the image forming start tip of the photoreceptor facing each of the transfer corona charger 8, the charge eliminating corona charger 10, and the optical charge remover 11. Ru. When the photoreceptor 1 rotates once and its start position (image formation start tip) reaches the start position, the output of the signal SPS becomes "L", thereby resetting the decimal counter 34. Further, since the output of the NAND gate 32 is always "H", the counter 31 receives a signal via the NAND gate 30 in response to the "H" signal from the AND gate 27, and counts this signal. At this time, the counter 31 counts "2" together with the earlier initial signal. Here, a reset signal is applied to the reset input terminal of the flip-flop 36 for driving the main motor relay 38 via the differentiating circuit 40 in response to a signal before the start position of the photoreceptor 1 is detected. However, the signal ISB applied to the set input terminal of the flip-flop 36 remains "L" until the signal SPS is output five times and the counter 31 counts "5". is not reset and remains set.

After that, the photoconductor 1 rotates, and if it rotates four times from the time when the first signal SPS was output, the counter 31
counts “5”. As a result, the output of the NAND gate 32 is inverted to "L", and the inverter 3
The signal ISB is inverted to "H" through the signal ISB. Therefore, the output of the NAND gate 32 becomes "H", and from now on, the start position signal SPS due to the rotation of the photoconductor is
The counter 31 never counts. This prevents malfunctions by not counting the rotation of the photoreceptor 1 during normal copying operations.

Subsequently, the signal ISB is inverted to "H", and since the photoreceptor continues to rotate, the starting position faces the corona charger 2, and a signal is output. As a result, the output of the NAND gate 44 becomes the signal
Since ISB is "H", it is inverted to "L", the reset terminal of the flip-flop 43 becomes "L", the flip-flop 43 is reset, and the operation of the corona charger 2 is stopped. Similarly, the lamp 50 is turned off by a signal, the operation of the transfer corona charger 8 is stopped by a signal, the operation of the charge eliminating corona charger 10 is stopped by a signal, and the lamp 59 is stopped by a signal.
is turned off.

Photoconductor 1 continues to rotate, and the slit signal PA
- When ₆ is output, a corresponding signal is output from the decimal counter 34. This signal is applied to the reset input terminal of the flip-flop 36 of the amplifier 3.
9 and the differentiating circuit 40,
Flip-flop 36 is reset because the set input terminal is at "H". Therefore, the driving of the main motor relay 38 is stopped, the main motor is stopped, and the starting position of the photoreceptor 1 is brought to match the starting position and stopped. When the above-mentioned operation is completed, the optical memory generated by opening the upper part 15 of the copying machine main body is removed. After this optical memory removal operation, if the copying machine becomes capable of copying, the copying operation will start and image formation will occur in conjunction with the operation of the copy switch, but since the optical memory has been removed, It is possible to obtain an image comparable to that obtained before the copying machine was opened. In this case, it is more effective to start image formation after performing the preprocessing for copying as specified in Japanese Patent Application Laid-Open No. 105553/1983.

In addition to paper jams, the upper part 15 of the copying machine body is opened for maintenance and the like. in this case,
After opening the power switch 21 or the door switch 22, the upper part 15 and the lower part 16 are separated, and after the maintenance is completed, the upper part 15 and the lower part 16 are closed. Then, when the power switch 21 or the door switch 22 is closed again, driving is performed to eliminate the optical memory effect described above. In other words, the reset terminal R of the flip-flop 29 is set to "L".
The flip-flop 29 is reset when the copying machine is closed and the power is supplied, and the signal is
Since IRA starts from "L", the above-described operation is performed in the same manner.

In the above explanation, the photoreceptor 1 is rotated four times, and during that time, the corona chargers 2, 8, 10 and the lamp 5 are
0,59 are driven, but the number of times is not necessarily limited to this, as it changes depending on the conditions of various devices including the photoreceptor 1, the intensity of the external light 19, its irradiation time, the expected safety factor, etc. .

Further, in the above explanation, the corona charger 2 is driven to uniformly charge the photoreceptor 1 to the polarity required for image formation, and then so-called uniform exposure is performed, but the charged charges are discharged by this exposure. . However, in order to charge the photoreceptor 1 to the polarity required for image formation,
Even if the corona charger 2 is not driven, the transfer corona charger 8 may be driven. Therefore, at least the corona charger 8 for transfer and the corona charger 1 for neutralization are provided.
0 and optical static eliminator 11, the object of the present invention can be achieved. In other words, the corona charger 2 and the lamp 50 need not be driven by the signal from the decimal counter 34, and the circuits shown in FIGS. 4b and 4c can be omitted.

Next, an example will be described.

Organic semiconductor photoreceptor 1 as external light 19
After irradiating at 3000l _x for 5 minutes, it was rotated at a circumferential speed of 150mm/sec. When this photoreceptor 1 was charged with a corona charger 2 with a discharge voltage of 7.2 k and a current of 1.2 mA, its surface potential was 40 to 60% of the charged potential of 500 V before irradiation due to the optical memory effect.
It dropped to .

Subsequently, for optical memory removal according to the present invention,
Corona charger for transfer 8, corona charger for charge removal 10
After driving the optical static eliminator 11 and rotating the photoreceptor once, driving the corona charger 2 in the same manner as described above,
Upon charging, the surface potential of the photoreceptor was restored to approximately 85%.

Thereafter, after repeating the above operation four times and charging in the same way, the surface potential of the photoreceptor will recover to about 95%, and even if you copy at this point, the quality will be almost the same as the copy before irradiation. No difference was observed.

As explained above, according to the optical memory removal device of the present invention, the operation for removing the optical memory generated on the photoreceptor each time in connection with the separation of the upper and lower parts of the copying machine body is performed in response to the supply of power. Since this is executed before image development is started, the image quality equivalent to that of the copied image before separation can be maintained, and the copying machine can always be used in a stable state.

In addition, there is no need for any special means to detect the optical memory generated on the photoconductor, and the optical memory can be reliably detected before copying image formation, not only for jam removal but also when separating the upper and lower parts due to maintenance or other reasons. can be removed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an electrophotographic copying machine according to the present invention, FIG. 2 is an external view showing the main body of the copying machine separated into upper and lower parts, and FIG. 3 is a control circuit for removing an optical memory according to the present invention. 4 is a plan view showing an example of a synchronous disk; FIGS. 5 a to 5 are circuit diagrams showing an example of a drive circuit for driving each copying process; FIG. The figure is a time chart for explaining the operations of FIGS. 4 and 5. 1: Photoreceptor, 2: Corona charger, 6: Illumination device, 8: Corona charger for transfer, 9: Copy paper, 1
0: Corona charger for static elimination, 11: Optical static eliminator, 1
5, 16: Upper and lower parts of the copying machine body, 17: Spring, 19: External light, 20: Detection switch, 2
1: Power switch, 22: Door switch, 40:
Main motor relay, 47, 53, 56: High voltage generation circuit, 50, 59: Lamp, SPS: Photoconductor start position signal, IRA: Initial reset signal, ISB: (5) count signal of signal SPS.

Claims (1)

[Claims] 1. Charging, image exposure,
An electrophotographic copying machine that performs development, transfer, and cleaning to enable repeated use and transfers an image formed on the photoreceptor to copy paper, comprising a photoreceptor and a photoreceptor arranged around the photoreceptor. an image forming means for repeatedly forming images on the copying machine; a copying machine main body that houses the photoreceptor and the image forming means and is configured to be separable substantially along the conveying path of the copy paper; and the copying machine a detection means that detects when the copying machine main body changes from an open state to a closed state and outputs a signal in response to the switching of the copying machine main body when power is supplied; In order to remove the optical memory caused by the irradiation of external light, the photoreceptor is rotated multiple times and the rotating photoreceptor is charged, and a part of the image forming means is activated to remove this charged charge. and an optical memory removing means that immediately energizes the optical memory removing means when the detecting means outputs a detection signal due to the upper and lower separation in response to power supply after the copying machine main body is in the closed state, and An optical memory removal device for an electrophotographic copying machine, comprising: a control means for removing the optical memory before starting a copying operation.