JPS5855943A - 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 such as a transfer copying machine.

Conventionally, copying machines use a rotating photoreceptor to perform latent image formation, printing, transfer, residual image removal, jam detection, etc., but the rotation of the photoreceptor generates a series of pulses, and these pulses are counted to perform various functions. There are some that perform timing control.

In this case, if there is an abnormality in this pulse, an error will occur in the timing, so this abnormality is detected and the power to the device is cut off.

However, if the power supply line is regularly disconnected, in some cases, a toner image remains on the rotating body, a high potential charge remains, or a transfer paper being separated remains.

Therefore, when copying is resumed, the inconveniences II and & may occur in the operation of the first sheet.

In order to eliminate the defects of misfire 1j1a and above, even if a pulse abnormality is detected, some operations are stopped, but the rotating body is not stopped, and full-throttle cleaning, uniform potential across the entire surface, and ejection of the transfer material are performed, and the process is completed. Wait and stop.

Further, in the present invention, when a pulse abnormality is detected during pulse counting for operation #lK+, a separate timer is started and operation control is changed. can be completed.

In addition, in the present invention, in a device that generates pulses in response to the rotation of a rotating body, it is possible to distinguish between an abnormality in the pulse generating element and an abnormality in the rotating body, and perform the compensation control described above only in the case of the former.

The present invention will be explained below with reference to Figure 1 of an example of a copying machine.

This is an electrophotographic copying machine using the body development transfer method.
i Place the original Os to be copied on a transparent original placing table with the leading edge of the original Os aligned with the reference position of the original placing table, and press it with the original cover 2. A lamp for illuminating the original 3 is located below the original placing table 1.
A movable lens 4, 5, a fixed in-mirror lens 6, a mirror 7, and a photosensitive drum 8 are arranged at the solid line position shown in the figure. Further, a seven-amplifier 50 is provided to cool the original table which is heated by the lamp for illuminating the original.

When a copy key (not shown) is pressed, the photosensitive drum device and each lamp start operating, and at the same time, the original illumination lamp 6 and movable mirror 4.5, which are the movable parts of the optical system, move to the positions shown by broken lines in the figure. When the sensory drum 8 completes a predetermined rotation, a signal to start exposure is issued, and the document illumination lamp 5.71
! , 11 mirror 4 starts moving rightward from the broken line position in the figure at a speed equal to or - the circumferential speed of the photosensitive drum 8, and the second mirror 5 starts moving rightward from the broken line position in the figure at half the speed.

Original O illuminated from below by the original illumination lamp 6
The image a is produced by an optical system consisting of movable mirrors 4 and 5, an in-mirror lens 6, a mirror 7, etc.
rise above. When the exposure is completed by a signal corresponding to the size, the document illumination lamp 3 is turned off, the lamp 3 and the movable mirrors 4 and 5 stop moving to the right in the drawing, and immediately return to the opposite direction, that is, to the left in the drawing. The above operation is repeated according to the number of copies specified in advance by a key (not shown). When the exposure for the specified number of sheets is completed, the document illumination lamp 3 and the movable mirrors 4 and 5 return to the predetermined positions indicated by solid lines in the figure and stop. Note that the speed of movement to the left in the figure is faster than the speed of movement to the right in the figure, increasing copying efficiency. here 5
Reference numeral 1 is a blanking lamp that is lit when the lamp 3 is off, and is turned off when the lamp 3 is turned on, to minimize toner removal during non-exposure.

The photosensitive drum 8 has a photosensitive layer coated with a transparent insulating layer, and is rotated clockwise in the drawing as described above. Eight photosensitive drums are first supplied with high-voltage current from a high-voltage power supply (not shown), and are then subjected to AC charge removal by an AC static eliminator 10 and at the same time exposed to light by a lamp 11 to eliminate charges on the surface of the insulating layer and inside the photosensitive layer. The primary charger 1 is erased and is then supplied with high voltage current (g) from a high voltage power source (not shown).
2, it is charged to (1). Subsequently, when reaching the exposure section 9, the book from the illumination section 13 is exposed to slit light and at the same time receives an AO@electronic charge from an AO static eliminator 1514 to which an ACLJE current is supplied from a high-voltage power supply (not shown). Then, an electrostatic latent image is formed on the surface of the photosensitive drum 15 by exposing the entire surface to light by the lamp 15, and the image enters the developing device 16. Developer 1
6 is a container 17 for storing developer, present @tt-918, Vl
The electrostatic latent image on the photosensitive drum 8 is visualized by the developer magnetically attracted to the developing loaf 18. Next, the transfer paper P fed from the paper feed unit comes into close contact with the photosensitive drum 58, and is charged by the transfer charger 20 with a (+) high voltage current from the high voltage power supply, so that the paper P on the photosensitive drum 8 is placed on the transfer paper P. transcribed into. After the transfer, the transfer paper P is neutralized by a separation static eliminator 21 to which an AC high voltage current is supplied from a high voltage power source, and its attraction force with the sensing drum 8 is weakened. Next, the transfer paper P is transferred to the 4-ra 23 in the 22nd copy.
The belt 24.
The guide 25 guides it to the fixing section 26 . Photosensitive drum 8
The remaining developer is wiped off by the edge portion 271 of the nine-blade tarliner 27, and the next cycle is repeated. After repeating the above-mentioned cycle for the pre-specified number of nine sheets, repeat the rotation for one more time, and then remove the static charge from the above-mentioned muC! 1
The internal charge of the photosensitive layer is removed by static elimination by 4 and full exposure by lamp 15, and the photosensitive layer rotates a predetermined amount in preparation for the next cycle and then stops.

FIG. 2 is a cross-sectional Iff diagram of a disk 51, having a hole 52, which is rotated at several times the Q, ) ram to generate a series of tallock pulses to form a control pulse. 56
is a photo-interchanger provided with a light-emitting diode 54 and a receiver jt and an x-ray 55 opposite to the drum, and generates a series of pulses DP from the light-receiving element 55 in accordance with the rotation of the drum. It is also possible to provide this disk 51 in a motor that drives an optical system mirror.

Figure 6 shows the microcontroller for determining the pulse status and for each process. It has a program memory ROM shown in the flowchart shown in FIG. 4, and performs the above judgment and control. CPB is a signal generated by copy methane (not shown), vl., v24 is a drive power supply, a drive signal for the main motor that rotates the Mxa drum, and HVT t is a signal for applying high voltage to the v11 primary charger 10 and 12 transfer charger 20. The signal HVT2 is a signal for applying high voltage to the secondary charger 149 and the separated Teiden 21, and the AEXFi front lamp 11. Full surface lamp 15, IEX
is a signal to turn on the hagen lamp 5, FAD is a signal to start scanning, PF is a signal to start feeding paper from a cassette, DISP is a signal to display an abnormality warning, and all are input/output connected to microcomputer M. Ru. The input circuit to the microcontroller is the circuit that determines the state of the pulse DP, and the G
a15,16. It has a filter that receives power from Ra44. The pulse DP may be generated from an oscillator separate from the disk, which oscillates at a frequency of about 5 KHz. In that case, the main motor is configured as a synchronous motor such as a pulse motor driven by this oscillator.

When a pulse is generated at this frequency, the Qal5 transistor turns on. Therefore, it becomes OK as input of 9 of Qalo. On the other hand, since the main motor drive signal is turned on when it is 1, 1 is input as the input of 8 of Qal 0. Therefore, the output PS of QaiO becomes 0. However, when the above-mentioned click pulse DP occurs while the motor is driving, the Qal 5 transistor turns off and Q
The PS of alo is 1. This 1 is inputted to the input port->XS of the microcomputer M as an abnormal input signal.

In Fig. 4, when the power switch (not shown) is turned on!
Icon M starts program processing and first determines the input of the copy button signal OPB via input port 1 (
Step 1). At the time of input, main mode pMl, HVTI
, HVT, AKXttt (Step 2) Next, it is determined whether the pulse state signal PS is 1 or 0 (Step 3). When it is 1, set the microcontroller's internal timer,
The drum is brought to a post-rotation process (step 4). As is well known, the microcontroller processes the program according to the microcontroller's pulses, or processes the micropulses a predetermined number of times within the microcontroller, or performs internal counting operations by repeating step NOP a predetermined number of times as a program. can be done. During this timer operation, the HVT charger is turned off to stop the charging action, and the HVTx and AlCl are continued to eliminate the charge of the drum and equalize the potential.
The potential of the photoconductive layer is made uniform by setting the temperature of T and using only the light source of the lamp EX. 1M when the timer expires for at least more than the drum rotation, which also serves as a cleaning effect.
1. The system BX is turned off and stopped (step 5). At step 4, turn on DISP and display a warning.When the 6-pulse status signal t8 is 0, count 1% of the pulse DP through the input port E3, stop the forward rotation when the force is increased, continue to turn on IEX, and turn on FAD. Then, the latent image forming step is carried out. 1. , TPFt is turned on. Similarly, during the counting of sl and 162, the signal PS is 1 or 0.
If there is an abnormality, the process moves to step 4. After repeating the desired number of spindles, enter the post-rotation for the same effect as above, count the pulses to vhs, execute step 5, and stop. During this counting, the signal PS is also determined, and at 10 o'clock, the internal timer is used to change the process in order to complete the action of the post-rotation.

The main printer is a transfer paper conveyance system 23, 24, 42.
.

45, 47, and 48, it is possible to eject paper that is only one minute away.

In Fig. 4, after turning on the copy button, turning on M1 and confirming that the signal PS is 0, HVTl and HV are turned on.
By turning on the T, it is possible to prevent deterioration of the photoreceptor due to charging when the drum is stopped when the signal Ps is 1 due to the drum being stopped.

In addition, when the pulse DP is generated by the rotation of the drum, if another photo interrupter is installed to detect the movement of the conveyance system driven by the main motor Ml, then when other abnormalities are determined in step 3, the interrupter will detect the cause of the failure. You can tell the difference between what you do and what you do. In the former case, when the signal PS is 1, all power supplies are disconnected at the same time as a warning.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a copying machine to which the present invention can be applied. Fig. 2 is a plan view of the means for detecting the state of the rotating body in the present invention, Fig. 3 is an example of a control circuit in the present invention, and Fig. 4 is a p-chart diagram of the control shown in Fig. 3. In the figure, 8 is a drum, 51 is a disk, and 14 and 20 are roller chargers. Applicant Canon Co., Ltd.

Claims (1)

[Claims] (1) A means for forming an image on a rotating body and performing processes such as transfer, residual image removal, and jam detection; a means for generating a series of pulses; and a means for generating a series of pulses; an image forming apparatus ( 2) means for forming an image on a rotating body and performing processes such as transfer, residual carbon removal, jam detection, etc., means for generating a series of pulses;
means for counting the pulses and controlling at least one of the gas supply means, and when an abnormal state is detected during counting the pulses, a separate timer is started to execute the operation of the control means. An image forming device characterized by and