JPH07152297A - Cleaner - Google Patents

Abstract

PURPOSE:To provide a cleaner which prevents unsatisfactory cleaning, improves the durability of a blade and prevents the blade from curling up. CONSTITUTION:The cleaner is provided with the blade 17, in contact with the surface of a photoreceptor 5, which removes developer sticking to the surface of the photoreceptor 5, a residual-developer quantity detecting means 30, upstream from the blade in the direction of the rotation of the photoreceptor 5, which detects quantity of developer remaining on the surface of the photoreceptor 5 after transfer, and pressure adjustment means 20 and 11 which adjust the pressure of the blade 17 on the photoreceptor 5 based on the detection result of the means 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer,
The present invention relates to a cleaning device in an image forming apparatus such as a facsimile machine.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer or a facsimile machine, a toner image formed on the surface of a photoconductor is transferred onto a recording paper. However, since the transfer is not completely performed, the toner remains on the surface of the photoconductor after the transfer. Therefore, there is provided a cleaning device that presses a blade onto the surface of the photosensitive drum to remove the toner remaining on the surface of the photosensitive drum.

As a cleaning device of this type, a detector is provided downstream of the cleaning position by the blade in the rotational direction of the photosensitive drum and detects the amount of toner adhering to the surface of the photosensitive drum after cleaning. A device having means for increasing the pressure contact force of the blade when the detected toner amount is not less than a predetermined value has been developed (see Japanese Patent Laid-Open No. 63-58475).

[0004]

Problems to be Solved by the Invention JP-A-63-5847
In the above-mentioned conventional cleaning device described in Japanese Patent Publication No. 5, the amount of toner adhering to the surface of the photosensitive drum after cleaning is detected, and when the detected amount of toner is above a predetermined value, the pressure contact force of the blade is increased. There is. That is, when a cleaning failure is detected, the pressure contact force of the blade is increased to enhance the cleaning effect.

By the way, in a cleaning device using a blade, the toner adhering to the surface of the photosensitive drum also acts as a lubricant between the blade and the photosensitive drum.
Therefore, at the cleaning position, when the amount of toner on the surface of the photoconductor drum is small, the lubricating action is reduced, so that the amount of wear of the blade is increased and the blade is easily deteriorated. In addition, the blade is likely to roll up.

In the above-mentioned conventional apparatus, when the amount of toner on the surface of the photosensitive drum is small at the cleaning position, no measures are taken, and therefore, there is a problem that the blade is likely to deteriorate.

It is an object of the present invention to provide a cleaning device capable of preventing defective cleaning, improving the durability of the blade and preventing the blade from rolling up.

[0008]

A cleaning device according to the present invention is provided with a blade for contacting the surface of a photoconductor to remove a developer adhering to the surface of the photoconductor, and an upstream side of the blade position in the rotational direction of the photoconductor. The residual developer amount detecting means for detecting the amount of developer remaining on the surface of the photoconductor after transfer and the detection result of the residual developer amount detecting means, the pressing force of the blade to the photoconductor is adjusted. It is characterized in that a pressure contact force adjusting means is provided.

As the pressure contact force adjusting means, when the amount of the developer detected by the residual developer amount detecting means is large, the pressure contact force of the blade with respect to the photosensitive member is strengthened, and the developer detected by the residual developer amount detecting means. When the amount is small, a blade that adjusts the pressure contact force of the blade with respect to the photoconductor is used so as to weaken the pressure contact force of the blade with respect to the photoconductor.

[0010]

The amount of developer remaining on the surface of the photoconductor after transfer is detected by the residual developer amount detecting means provided upstream of the blade position in the rotation direction of the photoconductor. And
Based on the result of this detection, the pressure contact force of the blade with respect to the photoconductor is adjusted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a digital copying machine will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of a digital copying machine.

Optical information obtained by exposing the image of the original is sent to the CCD 2 via the lens 1 and converted into an electric signal. The output signal of CCD 2 is the signal processing circuit 3
And the output signal of the CCD 2 is processed and edited. The output of the signal processing circuit 3 is sent to the laser unit 4 and converted into an optical signal (laser light). The laser light output from the laser unit 4 is applied to the photosensitive drum 5. As a result, an electrostatic latent image is formed on the photosensitive layer on the surface of the photoconductor drum 5. The photosensitive drum 5 is rotationally driven in the direction of the arrow by a main motor (not shown).

Around the photosensitive drum 5, a charger 6 for charging the photosensitive layer on the surface of the photosensitive drum 5, and a developing device for visualizing an electrostatic latent image formed on the photosensitive layer as a toner visible image. 7, a transfer discharger 8 for transferring the toner image formed on the photosensitive layer onto the recording paper, a separation discharger 9 for separating the recording paper from the photosensitive drum 5, and a photosensitive drum 5 after the transfer. A residual toner amount detector 30 for detecting the amount of toner remaining on the surface, and a cleaning device 1 for removing the toner remaining on the surface of the photosensitive drum 5 after transfer.
0 etc. are arranged.

The residual toner amount detector 30 is provided around the photosensitive drum 5 and at a position between the separating discharger 9 and the cleaning device 10. That is, the residual toner amount detector 30 is provided upstream of the blade position in the rotation direction of the photosensitive drum 5. Residual toner amount detector 3
As 0, for example, a reflection type photo interrupter is used. The output of the residual toner amount detector 30 is sent to the control circuit 20.

The cleaning device 10 includes a solenoid 1
1, a lever 13 pivotally supported by a fulcrum 12, a tension coil spring 14, an L-shaped holder 16 pivotally supported by a fulcrum 15, and a blade 17. One end of a lever 13 is pivotally attached to the tip of the plunger 11a of the solenoid 11. The other end of the lever 13 has a tension coil spring 1
4 is attached at one end. The other end of the tension coil spring 14 is attached to one end of the holder 16. A blade 17 is attached to the other end of the holder 16.

When the plunger 11a of the solenoid 11 moves in the retracting direction, the tension coil spring 14 is pulled down, the holder 16 swings counterclockwise around the fulcrum 15, and the blade 17 is pressed against the photosensitive drum 5. Power is strengthened. On the contrary, when the plunger 11a of the solenoid 11 moves in the advancing direction, the tension coil spring 14 is pulled up, the holder 16 swings clockwise around the fulcrum 15, and the pressing force of the blade 17 to the photosensitive drum 5 is increased. Weakened. The solenoid 11 is controlled by the control circuit 20.

By the way, when the amount of residual toner after transfer is large, cleaning failure is likely to occur. Therefore, it is preferable to increase the pressure contact force of the blade 17 to enhance the cleaning effect. When the amount of residual toner after transfer is large, the amount of residual toner remains
And acts as a lubricant between the photosensitive drum 5 and
The blade 17 is less worn.

On the other hand, when the amount of residual toner after transfer is small, the lubricating action between the blade 17 and the photosensitive drum 5 is reduced and the blade 17 is easily worn, so that the pressure contact force of the blade 17 can be weakened. preferable. When the amount of residual toner after transfer is small, even if the pressure contact force of the blade 17 is weakened, the amount of toner to be cleaned is small, so cleaning failure is less likely to occur.

The control circuit 20 detects the amount of residual toner after transfer based on the output of the residual toner amount detector 30,
The solenoid 11 is controlled so that the pressure contact force of the blade 17 is increased when the amount of residual toner is large, and the pressure contact force of the blade 17 is decreased when the amount of residual toner is small.

That is, the control circuit 20 controls the plunger 1 of the solenoid 11 when the residual toner amount after transfer is large.
The solenoid 11 is controlled so that 1a moves in the retreat direction. Therefore, in this case, the pressing force of the blade 17 against the photosensitive drum 5 is strengthened, and the cleaning effect is enhanced.

The control circuit 20 controls the plunger 1 of the solenoid 11 when the residual toner amount after transfer is small.
The solenoid 11 is controlled so that 1a moves in the advancing direction. Therefore, in this case, the pressing force of the blade 17 against the photosensitive drum 5 is weakened, the abrasion of the blade 17 is prevented, and the winding of the blade 17 is prevented.

According to the above-described embodiment, the pressure contact force of the blade 17 is strengthened when the amount of residual toner is large, and the pressure contact force of the blade 17 is weakened when the amount of residual toner is small.
Cleaning failure can be prevented, the durability of the blade 17 is improved, and the blade 17 is prevented from rolling up.

[0024]

According to the present invention, cleaning failure can be prevented, the durability of the blade can be improved, and the blade can be prevented from rolling up.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a schematic configuration of a digital copying machine.

[Explanation of symbols]

 5 Photosensitive Drum 10 Cleaning Device 11 Solenoid 17 Blade 20 Control Circuit 30 Residual Toner Amount Detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Sueyoshi 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka Within Mita Kogyo Co., Ltd. (72) Hiroyuki Hamakawa 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka No. 28 Inside Mita Industry Co., Ltd.

Claims (2)

[Claims] 1. A blade for contacting a surface of a photosensitive member to remove a developer adhering to the surface of the photosensitive member, the blade being provided upstream of a blade position in a rotation direction of the photosensitive member and remaining on the surface of the photosensitive member after transfer. A cleaning device including residual developer amount detecting means for detecting the amount of developer present, and pressure contact force adjusting means for adjusting the pressure contact force of the blade with the photosensitive member based on the detection result of the residual developer amount detecting means. . 2. The pressure contact force adjusting means strengthens the pressure contact force of the blade with respect to the photoconductor when the amount of the developer detected by the residual developer amount detecting means is large, and the developer detected by the residual developer amount detecting means. The cleaning device according to claim 1, wherein when the amount is small, the pressure contact force of the blade with respect to the photoconductor is adjusted so as to be weakened.