JPS58211777A - Image forming device - Google Patents

Abstract

PURPOSE:To clean a dirty transfer drum meshes and to prevent leaking to an electrifying device by rotating a transfer drum automatically after specific jam processing for cleaning the meshes of the transfer drum in case of jamming, and operating a cleaner simultaneously. CONSTITUTION:In a figure, A, B, and C are jam detectors, and a form after transfer 22 is separated by a separating pawl 23 and discharged from a discharge opening 29 to a part 30 through a conveyor belt 24 and a fixation device 25. The on-off operation of the load of a copying machine and input processing of an input signal, e.g. jam detection signal are all controlled by a microcomputer 31. Once a normal state is returned to after the prescribed jam processing, a photosensitive drum is stopped and the transfer drum is rotated; and a solenoid is turned on the take one turn while bringing the cleaner into contact, and then the cleaner is released to stop the transfer drum. The transfer drum is cleaned and then a stand-by state is set.

Description

[Detailed description of the invention] The present invention relates to sequence control of copying machines and the like.

FIG. 1 shows an example of a conventional color copying machine. 1 is a transfer drum around which copy paper 6 is wrapped, and 7 is a transfer drum for transferring the image; 2 is a photosensitive drum on which the image 1; A brush 5 is used to move the support part 9 in the direction of the arrow.
It is a rotating brush that comes into contact with the transfer drum surface and then moves away. The sheet of copy paper is fed in the S direction, the timing is taken by the registration rollers 1, the leading end is held firmly by the grip cap 10, and the sheet is wound around the transfer drum 1.

4.5 is synchronized during operation, and contact/release is controlled.

Conventionally, as shown in the timing chart of FIG. 2, the transfer drum was rotated before and after one copy to clean mesh stains on the transfer drum caused by scattered toner and the like. This cleaning operation is prohibited while the copy paper is wrapped around the transfer drum. However,
As shown in Figures 1 and 3, the stains on the transfer drum mesh are caused by a mistake in holding the copy paper on the transfer drum (grip mistake), and the transfer charger detects the presence of a person while the copy paper is not wrapped around the transfer drum. This is most noticeable when the toner on the photosensitive drum is transferred to the transfer drum mesh. This toner stain on the transfer drum mesh causes electrical discharge between the transfer IT device 7 and the highly charged photosensitive drum surface and the transfer drum mesh, and the toner stain that cannot be removed due to burnt toner and the microcomputer or the microcomputer due to noise. This caused the malfunction of the 1tnt gas element and caused a major problem in the operation of the machine.

In one example of the present invention, in order to clean the mesh of the transfer drum in the event of a jam, after a predetermined jam treatment, the transfer drum is automatically rotated and a cleaner is operated at the same time, thereby cleaning the mesh of the transfer drum. In the case of retention type copying, by rotating and cleaning the insulating drum when copying is interrupted, the image quality when restarting can be improved.

Further, the same effect can be obtained by rotating and cleaning the developing roller when the sequence is interrupted.

The present invention will be explained in detail below. FIG. 6 is a sectional view of the structure of two-color copying. 1a and 1b are cassettes for storing copy paper,
2 a t 2 b are paper feed rollers, 3 a , 3 b
, 4.5 is a timing roller for timing the conveyance of the fed copy paper, 7 is a transfer drum for wrapping the copy paper for transfer, and 6 is a gripper 18 for holding the copy paper on the transfer drum. The photosensitive drums 98 to 9d for forming an image are developing devices that perform development on the photosensitive drum 8. On the photosensitive drum, 17 a? , b
Charging or neutralization is performed at t 18 * 19 t 21, and when the document surface 10 is irradiated by the exposure rung 11, the reflected light passes through the mirror 14 and the lens 13. mirror 14
After passing through nine color separation filters 15a to 15d and a mirror 16, 19
The position is irradiated and exposed. ■ and ol◎ in the same figure are jam detection devices each consisting of a light emitting part and a light receiving part,
Each of them forms a circuit as shown in FIG. 2 in Figure 1
The copy paper that has been transferred at position 2 is separated by a separation claw 23, passes through a conveyor belt 24, a constant N device 25, and is delivered to an output port 2.
9, the paper is ejected to the tray 30 and copying is completed. Turning on the load in this copier.

All input processing for turning off and input signals, such as jam detection signals, is controlled by the microcomputer 31 shown in FIG. Output signals for turning on and off the loads are generated by the CPU 31, sent to the output port 4, and sent to each load 69 via the buffer driver 66. Further, input signals 40 from various sensors are latched by the input port 5 via the interface circuit 7, taken into the CPU 31, and processed.

In FIG. 4, when there is a connection between the lamp 42 and the Cds receiving cable C element 440, the resistance across the Cds receiving element 440 is large, and the potential at point P exceeds the potential at point Q. Since the output of the comparator 47 falls to ``1'', the Tr 48 is turned OFF, and the output becomes 11 ('').
``1'' is input to 31.

When there is no paper between 42 and 44, the resistance at both ends of 440 becomes small, so the potential of point P is lower than the potential of point Q and is null, so the output of comparator 47 is l-1" υ, Tr48
is turned on, so the output becomes "L".

The signal is sent to the CPU via 57.35.
is entered as . Therefore, for example, after the copy button is turned on, the paper feed row 22a (or 2b) is activated, the timing of conveyance is determined by 3a (or sb) and 4.5, and after being firmly held by the gripper 6, the paper is copied onto the transfer drum 7. At the timing when the leading edge of the copy paper reaches the position of the transfer charger 22 with the paper wrapped around the paper, it is input to the CPU via the jam detector ■ and Shibara abort (no. 8 is 0'').
Therefore, when there is no paper, the CPU is regarded as a JAM, and the JA
Display M and take measures such as stopping the machine.

FIG. 6 shows the control flow. When a jam is detected (50), the entire load is turned off for safety. (51) After the predetermined jam removal in steps 52 to 54, when the normal state is restored, the transfer drum is rotated while the photosensitive drum is stopped, the solenoid is turned on, the cooler is brought into contact with the transfer drum, the drum is rotated one rotation, and then Turn on the crease and stop the transfer drum. After cleaning the transfer drum, the machine returns to standby mode (waiting for the copy button). Turn on the motor and solenoid to operate the transfer cleaner and brush
, OFF is controlled by the CPU 31K shown in FIG. In this embodiment, the cleaning rotation was performed once, but it is not only possible to perform the cleaning rotation multiple times, but also to control the static eliminating corona (not shown) in the same way to clean the area after an abnormal state such as a jam. There is no problem (even if the original state can be restored, and image formation can be resumed.

In steps 52 to 54, 52 is a step for determining whether the power switch is turned off, and the microcomputer can sense the power voltage depending on whether the power switch is turned on or off. Do not execute the following while the power switch is on. This includes turning the power voltage on and off in response to opening and closing of the media door. In other words, do not execute the following while the door is closed. In step 56, it is determined that the jammed paper has been removed, and if paper remains on the paper sensor on the path, the following steps are not performed. In step 54, the procedure for turning on the L1 manual reset button is executed.

Although not shown, a step of detecting that the door is closed may be provided between steps 54 and 55, so that when the reset switch is turned on and the door is closed, steps 55 and subsequent steps may be executed.

Corona during rotation after the above jam treatment 17.18, 19°22
It is desirable to turn it off. It is also possible to rotate the photosensitive drum 8 in the same state at the same time as the rotation of the photosensitive drum 8, and perform cleaning with the cleaner 20.

In this case, the bias voltages of the developing devices 9a to 9d are set in a direction in which toner does not adhere.

In particular, according to this embodiment, since the transfer drum is cleaned after a jam, not only is staining of the transfer drum mesh largely prevented, but also leakage from the charger etc. caused by adhesion of toner is prevented. Furthermore, malfunction of elements such as a microcomputer due to noise caused by leakage can be prevented.

As described above, it is possible to prevent unexpected inconveniences due to jams or other troubles caused by interrupting the sequence midway through the main switch being turned off.

[Brief explanation of the drawing]

6 is a block diagram of the copying apparatus of this embodiment, FIG. 4 is a jam detection circuit, FIG. 5 is a block diagram of the peripheral part of the microcomputer, and FIG. 6 is a control flowchart showing cleaning after a jam. In the figure, 7 is a transfer drum, 8 is a photosensitive drum, and 100 is a cleaning means. Applicant Canon Co., Ltd. No. 1 M = Creep +--. = To transfer driver

Claims (1)

Scope of Claims: (1) Process means for forming an image on a first rotating body 1 A second rotating body different from the first rotating body, and a means for cleaning or removing static from the second rotating body. An image forming apparatus characterized in that the image forming apparatus is configured to rotate the second rotating body to perform cleaning or neutralization when the sequence is stopped midway before completion of the sequence. (2) The image forming apparatus according to item 1, wherein the second rotating body is for transferring a color image on the first rotating body to a sheet. (6) In item 1, the second rotary member should be cleaned or static-eliminated after becoming ready for image formation after clearing the jam.
An image forming apparatus characterized by: 1. An image forming apparatus that rotates.