JPH0624607A - Rolling jam control device - Google Patents

Abstract

PURPOSE:To provide a rolling jam control device of simple constitution with which emergency stop can be performed without roll-in to a cleaning roller even when a rolling jam is generated. CONSTITUTION:In a control part 9, a jam control part 9a for receiving a rolling detection signal is provided and an ON/OFF command signal is outputted to a register clutch 7a to conduct appropriate intermittent rotation of a register roller. When a transfer paper sheet rolled on a peripheral surface of a photoreceptor drum is detected by a rolling detection sensor 23, a rolling detection signal is sent to the jam control part 9a to immediately cut off the register clutch 7a. Since a load and inertial force of the register roller are small, the roller having rapid responsiveness stops immediately and grips a rear end of the transfer paper sheet. Accordingly, the possibility of the transfer paper sheet rolled on the photoreceptor drum intruding into a cleaning roller is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding jam control device for preventing transfer paper from winding around the peripheral surface of a photosensitive drum of an image forming apparatus such as an electronic copying machine.

[0002]

2. Description of the Related Art In a photoconductor drum of an electronic copying machine or the like, a light source irradiates a document on a document glass with exposure light obtained by a mirror,
An electrostatic latent image is formed by irradiating the drum peripheral surface uniformly charged by the charging electrode through a lens or the like. This electrostatic latent image is developed by a developing unit to form a toner image,
A toner image is carried on the transfer paper via the transfer electrode and the separation electrode, the transfer paper is separated from the photoconductor drum by the separating claw, and is conveyed to the fixing unit in the next step by the conveying belt.
On the other hand, the surface of the photosensitive drum after the transfer is cleaned by a cleaning roller to prepare for the next image formation.

However, a so-called winding jam may occur in which the transfer paper that is in close contact with the photosensitive drum is not separated by the separating claws and rotates at the same time as the photosensitive drum. If this transfer paper enters the cleaning roller section, its removal work becomes very complicated. Therefore, in the winding jam control device provided in the conventional photosensitive drum, the winding detection is performed on the peripheral surface of the photosensitive drum. A sensor is provided so that the main drive motor of the image forming apparatus is urgently stopped when a winding jam is detected.

[0004]

However, since the main drive motor supplies not only the photosensitive drum but also the driving force for the developing unit, the cleaning unit, the fixing unit, and all other conveying systems, the load is large and the inertial force is large. . In the conventional winding jam control device, a reverse rotation brake is applied to the main drive motor to make an emergency stop. However, due to this inertial force, the rotation speed of the photosensitive drum is v1 = 400 mm / se.
If it is c, a stop time of 80 msec was required. However, the distance between the winding detection sensor and the cleaning roller is 20m.
Since it can take only about m, the required time for stopping after the jam detection is 50 msec or less. Therefore, even if the main drive motor is stopped urgently after being detected by the winding detection sensor, there is a large possibility that the transfer paper is caught in the cleaning roller.

Further, in order to apply a reverse rotation brake,
The reverse rotation drive must be stopped at the moment when the rotation of the photosensitive drum is stopped, which has a drawback that the structure of the winding jam control device becomes complicated.

An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional winding jam control device, and even if a winding jam occurs, it can be stopped without being caught by the cleaning roller. It is an object of the present invention to provide a winding jam control device that can be performed and has a simple structure.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a winding jam control device for preventing the transfer paper from winding around the peripheral surface of the photosensitive drum. The winding detection sensor arranged on the peripheral surface of the drum, the clutch for transmitting the driving force to the registration roller arranged upstream of the photosensitive drum, and the clutch based on the output of the winding detection sensor. It is characterized by having a jam control unit that can be intermittently operated.

According to a second aspect of the present invention, in the wrapping jam control device according to the first aspect, the wrapping jam detection sensor is attached to the photosensitive drum with respect to the rotation direction of the photosensitive drum. It is characterized in that it is arranged on the upstream side of the cleaning roller. Further, in the invention according to claim 3, in the wrapping jam control device according to claim 1, the distance between the wrapping jam detection sensor and the registration roller is shorter than the length of the transfer sheet which can be passed. Is characterized by.

[0009]

According to the invention described in claim 1, when the winding detection sensor detects the transfer paper wound around the peripheral surface of the photosensitive drum, a signal is sent to the jam control section of the registration roller arranged upstream of the photosensitive drum. Release the clutch. Since the registration roller has a small load and a small inertial force, the responsiveness of the clutch is quick and the registration roller stops immediately. Since the transfer paper is stopped while being sandwiched by the registration rollers, it will not be fed ahead even if the photosensitive drum rotates.

According to the second aspect of the present invention, the winding jam detection sensor detects a jam in front of the cleaning roller, so that the transfer paper does not enter the cleaning roller. Further, in the winding jam control device according to the third aspect, the distance between the winding jam detection sensor and the registration roller is made shorter than the length of the transfer paper which can pass the paper. Therefore, the winding detection sensor detects the transfer paper. Even when the clutch is disengaged, the trailing edge of the transfer paper is still held by the registration rollers, and even a small size transfer paper can be reliably stopped.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the winding jam control device of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus incorporating a winding jam control device, and FIG. 2 is a circuit block diagram of a jam control unit of the winding jam control device.

The image forming apparatus 1 is provided with a plurality of paper feed stages 2 and accommodates a transfer paper 3 in each of them. Each paper feed stage 2
On the upper surface of the transfer paper 3, the paper feed roller 4 and the double feed preventing means 5 are provided side by side, and the transfer paper 3 is sent to the next process one by one. The transfer paper 3 delivered from each stage is guided to a guide plate (not shown) and inserted into the transport roller 6. The transport roller 6 is linked to the sheet feed roller 4 of each sheet feed stage and is driven to form a transport path for each sheet feed stage 2. The transfer paper 3 delivered from the uppermost conveying roller 6 is inserted into the registration roller 7 arranged immediately before the transfer processing section. Registration sensor 8 arranged immediately before the registration roller 7.
When the transfer paper 3 is detected, sends a signal to the control unit 9 of the image forming apparatus 1 to stop the driving of the conveyance roller 6. At this time, the transfer paper 3 hits the registration roller 7 and stops, and the leading end of the transfer paper 3 is aligned in the direction perpendicular to the direction of travel.

On the other hand, in the photoconductor drum 10, uniform charging is given by the charging electrode 11, and the exposure light obtained by illuminating the original on the original glass 13 by the light source 12 is passed through the mirror 14, the lens 15 and the like. To irradiate the peripheral surface of the photosensitive drum 10,
Form an electrostatic latent image. This electrostatic latent image is developed by the developing unit 16
To form a toner image.

The control unit 9 controls the photosensitive drum 10 as described above.
The registration clutch 7a is connected to drive the registration roller 7 in synchronism with the rotation of the transfer roller 3, and the transfer paper 3 sandwiched by the registration roller 7 is sent to the transfer electrode 17 and the separation electrode 18 to carry the toner image. After that, the transfer paper 3 is separated from the photosensitive drum 20 by the separation claw 19, and the transfer belt 2
The sheet is mounted on 0 and conveyed to the fixing section 21 in the next step. A cleaning unit 22 is provided around the photosensitive drum 10 downstream of the separation claw 19 and the surface of the photosensitive drum 10 after transfer is cleaned by a cleaning roller 22a.
The electrode 11 for charging is charged again for the next image formation.

A winding detection sensor 23 for detecting the transfer paper 3 when it has entered through the separating claw 19.
Is provided in front of the cleaning roller 22a and sends a winding detection signal to the controller 9. The distance L between the winding detection sensor 23 and the cleaning roller 22a is about 20 mm.

An image forming apparatus receives a jam control unit 9a for inputting a winding detection signal, a speed command signal and an ON / OFF command signal from the jam control unit 9a, to a control unit 9 which constitutes the winding jam control device. It has a motor drive circuit 9b which sends a drive command signal to one main drive motor 24 and feeds back a speed information signal from this main drive motor 24 to control motor drive. Also, the jam controller 9a
Outputs an ON / OFF command signal to the registration clutch 7a to interrupt the rotation of the registration roller 7 as appropriate.

When the winding detection sensor 23 detects the transfer paper 3 wound around the peripheral surface of the photosensitive drum 10, a winding detection signal is sent to the jam controller 9a and the registration clutch 7a is immediately sent.
Turn off. Since the registration roller 7 has a small load and a small inertial force, it has a quick response and stops immediately. Photoconductor drum 1
The rotation speed of 0 (conveyance speed of the transfer paper 3) is v ₁ = 400 m
If it is m / sec, the response time of the registration roller 7 is about 10 msec, so that it stops at the progress of about 4 mm and the rear end of the transfer paper 3 is gripped. Therefore, the photosensitive drum 1
There is no fear that the transfer paper 3 wound around 0 will enter the cleaning roller 22a.

The distance L1 between the wrapping jam detection sensor 23 and the registration roller 7 is shorter than the minimum length of the transfer sheet 3 which can be passed. Therefore, even when the winding detection sensor 23 detects a jam and disengages the registration clutch 7a, the rear end of the transfer paper 3 is still held by the registration rollers 7, so that the transfer paper 3 of a small size can be reliably stopped. can do.

[0019]

As described above, according to the first aspect of the present invention, the jam control unit that can engage and disengage the clutch of the registration roller based on the output of the winding detection sensor is provided. Stop with an early response,
The transfer paper transfer can be immediately stopped. Since the transfer paper is stopped while being sandwiched by the registration rollers, the transfer paper is not fed further even if the photosensitive drum rotates.
Also, because you can stop immediately by simply disengaging the clutch,
The configuration of the jam controller can be simplified.

According to the second aspect of the invention, since the winding jam detecting sensor is provided in front of the cleaning roller, the transfer paper is prevented from entering the cleaning roller. Further claim 3
Since the wrapping jam control device described is shorter than the length of the transfer paper that can pass the distance between the wrapping jam detection sensor and the registration roller, even a small size transfer paper can be reliably stopped before the cleaning roller. be able to.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus including a winding jam control device.

FIG. 2 is a circuit block diagram of a jam control unit.

[Explanation of symbols]

 3 Transfer Paper 7 Registration Roller 7a Registration Clutch 9 Control Section 9a Jam Control Section 10 Photoreceptor Drum 22a Cleaning Roller 23 Winding Detection Sensor

Claims (3)

[Claims] 1. A winding jam control device for preventing transfer paper from being wound around a peripheral surface of a photosensitive drum, and a winding detection sensor disposed on the peripheral surface of the photosensitive drum, and the photosensitive drum. A winding jam control device having a clutch for transmitting a driving force to a registration roller disposed upstream of the winding roller, and a jam control unit capable of connecting and disconnecting the clutch based on an output of the winding detection sensor. 2. The winding jam control device according to claim 1, wherein the winding jam detection sensor is arranged upstream of a cleaning roller attached to the photosensitive drum with respect to a rotation direction of the photosensitive drum. A winding jam control device characterized by being installed. 3. The winding jam control device according to claim 1, wherein a distance between the winding jam detection sensor and the registration roller is shorter than a length of transfer paper which can be passed. Rolling jam control device.