JPH04324887A - Cleaning device - Google Patents

Abstract

PURPOSE:To reduce the burden of a driving system, and maintain a good cleaning effect over a long period. CONSTITUTION:A cleaning device 13 is a device for cleaning a photosensitive drum 8 in an image forming device which forms images with the rotating photosensitive drum 8. This device 13 is provided with a fur brush 21, a flicker brush 22. The fur brush 21 comes into contact with the surface of the photosensitive drum 8 while rotating. The flicker brush 22 comes into contact with the fur brush 21, and rotates in the opposite direction to the fur brush 21 and at a high speed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device, and more particularly to a cleaning device for cleaning a photoreceptor of an image forming apparatus.

0002

2. Description of the Related Art Image forming apparatuses (for example, copying machines and laser printers) generally form an electrostatic latent image on a rotating photoreceptor drum, develop the latent image with toner, and transfer the resulting toner image to paper. It is designed to be transferred to and,
Toner left on the photoreceptor drum after the transfer process is removed by a cleaning device.

As a conventional cleaning device, FIG. 3 shows a cleaning device disclosed in Japanese Patent Application Laid-open No. 116776/1983. The cleaning device 41 is placed in contact with the photoreceptor drum 42 . The cleaning device 41 is the casing 4
3, and a fur brush 44 inside the casing 43.
and a flicker brush 45. The fur brush 44 rotates in the direction of arrow A while contacting the photoreceptor drum 42, and wipes off toner adhering to the photoreceptor drum 42. The flicker brush 45 is in contact with the fur brush 44 and is rotating in the same direction (arrow B direction).

0004

In the conventional cleaning device described above, once the fur brush 44 starts rotating, the fur brush 44 continues to contact the photosensitive drum 42 from one direction, so that the fur gradually falls down. Furthermore, the fur brush 44 and the flicker brush 45 collide with each other from opposite directions at the contact portion. Therefore, the flicker brush 45 further promotes the fall of the fur of the fur brush 44.

Moreover, in the conventional cleaning device, since the fur brush 44 and the flicker brush 45 collide from opposite directions at the contact portion, a large torque is required for the fur brush 44 and the flicker brush 45. , the burden on both drive systems increases.

[0006] An object of the present invention is to provide a cleaning device that can reduce the load on the drive system and provide good cleaning effects over a long period of time.

[0007]

A cleaning device according to the present invention is a device for cleaning a photoreceptor in an image forming apparatus that forms an image using a rotating photoreceptor. This device includes a fur brush and a flicker brush.

[0008] The fur brush contacts the surface of the photoreceptor while rotating. The flicker brush is in contact with the fur brush and rotates in the opposite direction and at a higher speed relative to the fur brush.

[0009]

In the cleaning device according to the present invention, the flicker brush contacts the fur brush and rotates in the opposite direction to the fur brush at a higher speed. Therefore, since both are in contact while moving in the same direction at the contact portion, a large torque is not required, and the burden on the drive system of the fur brush and flicker brush is reduced. In addition, since the flicker brush makes contact with the brush at a higher speed than the fur brush, it can raise the fallen bristles of the fur brush. Thereby, the fur brush can effectively clean the photoreceptor over a long period of time.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a copying machine incorporating an embodiment of the present invention. In the figure, a document placement table 2 is fixed to the upper surface of a copying machine main body 1, and a document presser 3 is arranged on the document placement table 2 so as to be openable and closable. Copy machine body 1
Paper feed cassettes 4 and 5 are removably attached to the right side of the figure. A paper discharge tray 6 from which copied sheets are discharged is mounted on the left side of the copying machine main body 1 in the figure.

Inside the copying machine main body 1, an exposure device 7 for reading originals is provided at the top. This exposure device 7 is composed of a light source, a mirror, and the like. Further, a photosensitive drum 8 on which an electrostatic latent image is formed is arranged in the center of the copying machine main body 1. Photosensitive drum 8
Surroundings are a charging device 9 that charges the photoreceptor drum 8 to a predetermined charge, a developing device 10 that develops the electrostatic latent image, a transfer device 11 that transfers the toner image onto the paper, and a transfer device 11 that transfers the toner image from the photoreceptor drum 8 to the paper. A paper separating device 12 for separating the toner from the photosensitive drum 8 and a cleaning device 13 for removing the residual toner on the photosensitive drum 8 are arranged. Between the paper feed cassettes 4 and 5 and the image forming section composed of the photosensitive drum 8 and the like, and downstream from the image forming section, there are a paper feed conveyance path 14 and a paper discharge conveyance path 15 for conveying paper, respectively. is provided. A fixing device 16 is arranged between the paper discharge conveyance path 15 and the paper discharge tray 6 to fix the transferred image on the conveyed paper.

The details of the cleaning device 13 will be explained using FIG. 2. In the figure, the cleaning device 13 is
a fur brush 21 that comes into pressure contact with the surface of the photoreceptor drum 8;
Flicker brush 22 in contact with fur brush 21
, a screw conveyor 23 for discharging waste toner to the outside, and a casing 24 that houses them.

The fur brush 21 is rotatably driven in the direction of arrow Y around the center 01. Therefore, the fur brush 21 rotates so as to come into contact with the photosensitive drum 8 rotating in the direction of the arrow X from the opposite side. The fur brush 21 has, for example, an electric resistance 102 to
It is made of conductive resin with a thickness of 105 angstrom cm. Specifically, the fur brush 21 is composed of a carbon-arrayed organic conductive fiber in which fine particles of carbon black are linearly arranged on an acrylic polymer base, for example. More specifically, Toray SA-7 and Beltron 1
For example, it is composed of 2N.

The flicker brush 22 is a fur brush 2.
1 is placed in contact with the photoreceptor drum 8 on the opposite side to the side that contacts the photoreceptor drum 8. The flicker brush 22 is at the center O2
The fur brush 21 is rotated in the direction of arrow Z, which is opposite to the fur brush 21 . Therefore, the flicker brush 22 rotates so as to move in the same direction and contact the fur brush 21 at the portion where the flicker brush 22 contacts the fur brush 21. Further, the flicker brush 22 is configured to rotate at a higher speed than the fur brush 21. The flicker brush 22 has a lower density of bristles than the fur brush 21, and also has larger bristles. The flicker brush 22 is made of the same material as the fur brush 21.

In the copying machine described above, the photosensitive drum 8 is positively charged by the charging device 9.
Mainly negatively charged toner adheres to the surface of the photoreceptor drum 8 . Then, the fur brush 21 has a first
A positive terminal of a power source 25 is connected, and a negative terminal of a second power source 26 is connected to the flicker brush 22. As a result, the fur brush 21 has a positive potential opposite to that of the toner adhering to the photoreceptor drum 8, and the flicker brush 22 has the same negative potential as the toner.

[0016] The screw conveyor 23
4, and its center line is perpendicular to the paper surface of FIG. The casing 24 has an opening on the photoreceptor drum 8 side, and a lower seal 2 is attached to the edge of the opening.
9 and an upper seal 30 are attached. Both seals 2
9 and 30 are in light pressure contact with the surface of the photoreceptor drum 8 to prevent toner from scattering between the casing 24 and the photoreceptor drum 8.

A toner return prevention plate 31 is provided in the upper part of the casing 24 above the contact area between the fur brush 21 and the flicker brush 22. Toner return prevention plate 3
1 extends parallel to the centers O1 and O2, and its lower end reaches slightly above the contact area between both brushes 21 and 22.

Next, the operation of this embodiment will be explained. When the copying operation is started, paper is conveyed from the designated one of the paper feed cassettes 4 and 5 to the photosensitive drum 8 side. Meanwhile, the exposure device 7 starts scanning the original placed on the original placing table 2. Then, according to the image information read by the exposure device 7, an electrostatic latent image is formed on the photoreceptor drum 8. The photosensitive drum 8 on which the electrostatic latent image is formed is developed by a developing device 10, and the resulting toner image is transferred onto paper by a transfer device 11. The paper onto which the image has been transferred is conveyed to a fixing device 16, subjected to a fixing process, and then discharged onto a paper discharge tray 6. On the other hand, after the transfer process, the surface of the photoreceptor drum 8 on which toner remains moves into the cleaning device 13.

Inside the cleaning device 13, a positively charged fur brush 21 is rotating in the direction of arrow Y while contacting the surface of the photosensitive drum 8. As a result, the toner adhering to the surface of the photosensitive drum 8 is brushed off by the fur brush 21 and falls into the casing 24. Further, the negatively charged toner is attracted to the positively charged fur brush 21 and leaves the surface of the photoreceptor drum 8 .

Fur brush 21 and flicker brush 22
At the contact portion, the fur brush 21 is neutralized by the flicker brush having a charge of opposite polarity to that of the fur brush 21, and as a result, the toner easily falls from the fur brush 21 to the lower part of the casing 24. Further, the flicker brush 22 rotates at a higher speed than the fur brush 21, and brushes off toner that tends to separate. Note that the toner return prevention plate 31 prevents the toner that has flown up into the upper part of the casing 24 from returning to the fur brush 21 side.

Fur brush 21 and flicker brush 22
Since the fur brush 21 and the flicker brush 22 move in the same direction and make contact with each other, the fur brush 21 that falls down due to contact with the photoreceptor drum 8
bristles are raised by the flicker brush 22. As a result, the fur brush 21 is less likely to fall down,
The fur brush 21 reliably contacts the photosensitive drum 8 for a long period of time to perform good cleaning. Furthermore, compared to the fur brush 21, the flicker brush 22 has a lower density of flocked hair and a larger thickness of bristles. For this reason, the flicker brush 22 applies a mechanical combing action to the fur brush 21 to remove curls and the like.

Further, since the fur brush 21 and the flicker brush 22 rotate while moving in the same direction at the contact portion, a large torque is not required, and as a result, the load on the drive system is reduced.

[0023]

In the cleaning device according to the present invention, the flicker brush contacts the fur brush and rotates in the opposite direction to the fur brush at a higher speed. Therefore, according to the present invention, the burden on the drive system can be reduced, and the photoreceptor can be cleaned well over a long period of time by preventing the fur brush from falling.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a copying machine adopting an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 3 is a schematic vertical cross-sectional view of a conventional cleaning device.

[Explanation of symbols]

8 Photoreceptor drum 13 Cleaning device 21 Fur brush 22 Flicker brush

Claims (1)

[Claims] 1. An image forming apparatus that forms an image using a rotating photoreceptor, a cleaning device for cleaning the photoreceptor, comprising: a fur brush that contacts the surface of the photoreceptor while rotating; A cleaning device comprising: a flicker brush that is in contact with the fur brush and rotates in an opposite direction and at a higher speed than the fur brush.