JPH10312142A - Cleaner for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the cleaner which diminishes photoreceptor-drum wear and cleaning-blade wear and prevents a blade from being curled in or chattering. SOLUTION: In the cleaner for the image forming device which has the cleaning blade 72 for removing residual toner by being firmly pressed to an image carrier 1 consisting of a photoreceptor drum, and a hopper 71 for temporarily storing the toner scraped by the cleaning blade 72, the hopper 71 is divided into two, an upper storage part 74 and a lower storage part 75, by means of a netlike partition 73, and powder lubricant 9 is stored in the lower storage part 75. Each mesh (opening) of the net is smaller in size than the particle diameter of the lubricant and larger in size than the particle diameter of the toner. The toner and lubricant scraped off the image carrier gradually heap up, and reach the partition 73. At the time, only the toner passes through the net meshes and enters the storage part 74. However, the lubricant cannot pass through the partition 73 and stays in the lower storage part 75, thereby lubricating the surface of the image carrier 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cleaning of an image carrier such as a photosensitive drum in an image forming apparatus utilizing electrophotography.

[0002]

2. Description of the Related Art An image forming apparatus charges a surface of an image carrier such as a rotating photosensitive drum, forms an electrostatic latent image thereon, and applies a toner charged to the electrostatic latent image to the opposite polarity. The toner image is adsorbed and transferred to a transfer sheet for copying or printing. After the transfer to the transfer paper, the photosensitive drum repeats a cycle of continuing to rotate, forming an electrostatic latent image again, forming a toner image, and transferring the toner image.

However, a small amount of toner adheres to the image carrier after the toner image is transferred onto the transfer paper, and when the next image is formed as it is, the remaining toner is removed from the next transfer paper. Is transferred to the print, resulting in print stains.

Therefore, a cleaning device is provided on the image carrier to remove residual toner. In this cleaning device, a cleaning blade made of an elastic material such as rubber is pressed against a photosensitive drum to thereby scrape off toner remaining on the photosensitive drum. The scraped toner is collected in a hopper,
It is discharged by a screw conveyor or the like.

[0005] However, recently, in order to improve the quality of an image, the particle diameter of the toner has been reduced, and it has been impossible to scrape the toner unless the cleaning blade is strongly pressed against the photosensitive drum. As a result, the friction between the cleaning blade and the photosensitive drum increases, and the photosensitive drum gets caught in the cleaning blade, the cleaning blade vibrates to cause transfer omission (worm bite), and the rotation power of the photosensitive drum increases. And the wear of the cleaning blade and the photosensitive drum becomes severe.

Therefore, a powdered lubricant is put in a hopper and supplied between a cleaning blade and a photosensitive drum. Further, Japanese Patent Application Laid-Open No. 60-12571 proposes a cleaning device capable of changing an opening area of a hopper so as to always supply an appropriate amount of lubricant between a cleaning blade and a photosensitive drum.

[0007]

However, in the above-described cleaning device, the lubricant is pushed up by the toner or the like removed from the photosensitive drum, and is separated from the surface of the photosensitive drum so as not to come into contact with the lubricant. The role cannot be fulfilled, and the same problem as described above occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a cleaning device capable of reducing abrasion of a photosensitive drum and a cleaning blade and eliminating entangling and chattering of the blade.

[0009]

In order to achieve the above object, the present invention provides a cleaning blade for removing residual toner by pressing against an image carrier, and temporarily storing toner scraped by the cleaning blade. In the cleaning apparatus for an image forming apparatus having a hopper, the hopper is divided into two parts, and a powder lubricant is stored in one storage part.

Alternatively, the hopper may be divided into two parts in the normal direction of the image carrier, the lubricant accommodating portion may be arranged on the image carrier side, or the two-partitioned partition may be mesh-shaped. Or the opening of the mesh is smaller than the particle size of the lubricant and larger than the particle size of the toner, or the lubricant is coated on a material having a higher specific gravity than the toner. Can be.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cleaning device for an image forming apparatus according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of the cleaning device of the present invention and its peripheral portion. In FIG. 1, reference numeral 1 denotes an image carrier composed of a photosensitive drum. Around the image carrier 1, a charging roller 2, a developing device 3, a transfer device 4, a separation electrode 5, a transport guide 6, a cleaning device 7, a neutralizing lamp 8, and the like are arranged.

The charging roller 2 charges the surface of the image carrier 1 to a uniform potential. The developing device 3 includes a case 31, an upper lid 32, a doctor 33, a developing roller 34, a left screw 3
5, a right screw 36 and the like, and the toner accommodated in the case 31 is agitated while being circulated by the left screw 35 and the right screw 36, and a required amount of toner is supplied to the developing roller 34. Developing screw 34 from left screw 35
The surplus toner supplied to the case 31 is scraped off by the doctor 33 and returned into the case 31.

The paper feeding unit includes a pair of upper and lower registration rollers 4.
1 and 42 and upper and lower guide plates 43 and 44. When the transfer sheet is sent from a sheet feed tray (not shown), the transfer sheet is temporarily stopped at the registration rollers 41 and 42 and is sent in synchronization with the timing of the toner image on the image carrier 1 and the leading end of the transfer sheet. The fed transfer paper is transferred to a transfer roller 45.
And the image carrier 1, the toner image on the image carrier 1 is transferred.

The cleaning device 7 has a cleaning blade 72 attached to the lower end of a hopper 71, and the tip of the cleaning blade 72 is in contact with the image carrier 1. The hopper 71 has a mesh-shaped partition plate 73 in the middle and is divided into two storage sections 74 and 75, and the lower storage section 75 is open to the image carrier 1 side. These storage portions 74 and 75 are arranged in the normal direction of the image carrier 1, and a toner discharge screw 76 is provided in the upper storage portion 74.

The operation of the entire image forming apparatus will be described below. Here, a series of processes of image formation is performed in the example of N / P. When a print button of an operation unit (not shown) is pressed, a predetermined voltage or current is sequentially applied to the charge removing lamp 8, the charging roller 2, the developing roller 34, the transfer roller 45, and the separation electrode 5 at a predetermined timing. Almost simultaneously, the image carrier 1, the charging roller 2, the developing roller 34, the left screw 35, the right screw 36, the transfer roller 45,
The toner discharge screw 76 starts rotating in a predetermined direction.

The image carrier 1 is neutralized by a neutralization lamp 8 and is uniformly negative (-850 V) by a rotating charging roller 2 in contact.
And an electrostatic latent image is formed (black solid potential is -150 V) by laser light a irradiated from the direction of the arrow.

The latent image is developed by the magnetic brush formed by the developing roller 34 (applied voltage is -650 V) to form a toner image. Then, the toner image is transferred to the image carrier 1
Between the transfer rollers 45 and the registration rollers 41 and 42
The toner image is transferred (+10 μA) to the transfer paper fed at a proper timing, and the transfer paper is separated from the image carrier 1 by the separation electrode 5 and is heated by the fixing device (not shown) from the transport guide 6 to melt the toner. Is fixed and discharged as a copy outside the machine.

On the other hand, a small amount of toner transferred on the transfer roller 45 and remaining on the image carrier 1 reaches the cleaning device 7 by the rotation of the image carrier 1, where it is scraped off by the cleaning blade 72, The carrier 1 is removed from above.

The storage section 75 below the cleaning device 7 stores a lubricant 9 having a particle diameter larger than the particle diameter of the toner. On the surface of the image carrier 1, the cleaning blade 72
The lubricant 9 enters the “wedge” formed by the image carrier 1 and the lubricant 9 adheres to the surface of the image carrier while being pressed by the cleaning blade 72.

Most of the lubricant 9 thus adhered to the image carrier 1 is scraped off together with the toner by the cleaning blade 72, removed from the image carrier 1 and collected in the storage section 75 below the hopper. . Cleaning blade 7
A small amount of lubricant remains on the surface of the image carrier 1 that has passed through 2 and proceeds to the next image forming step.

The toner and the lubricant 9 scraped off from the image carrier 1 by the cleaning blade 72 are sequentially lifted upward and reach the net-like partition plate 73. This partition plate 7
Since the mesh (opening) of the mesh 3 is larger than the particle size of the toner and smaller than the particle size of the lubricant, only the toner reaches the toner discharge screw 76 beyond the partition plate 73 and is discharged. You. The lubricant 9 does not exceed the partition plate 73, stays in the lower storage section 75, and adheres to the image carrier 1 again.

When the lubricant 9 has a specific gravity higher than that of the toner, for example, a material obtained by coating the surface of a carrier mixed with the toner in the developing device 3 with a lubricant, the cleaning blade 7 is heavier than the toner.
When the toner is scraped off in step 2, the toner is lifted, and the lubricant 9 always stays below, comes into contact with the surface of the image carrier 1, and a stable supply of the lubricant becomes possible.

[0023]

As described above, according to the present invention, the hopper of the cleaning device is divided into two parts, and the lubricant is stored in one of the two parts. Lubricant can be supplied.

If the two storage portions of the hopper are arranged in the normal direction of the image carrier and the lubricant is stored on the image carrier side, the lubricant is pressed against the image carrier by its own weight, Lubricant can be supplied stably.

If the opening of the mesh-shaped partition plate is larger than the particle size of the toner and smaller than the particle size of the lubricant, only the toner can be selected and discharged by the toner discharge screw, and the lubricant can be reused. Consumption is also reduced.

If the lubricant is coated on a material having a specific gravity higher than that of the toner, the lubricant is constantly located below the toner and easily comes into contact with the image carrier, so that the lubricant can be stably and appropriately lubricated.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cleaning device of the present invention and a configuration around an image carrier of an image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image carrier 3 Developing device 4 Transfer device 7 Cleaning device 71 Hopper 74, 75 Storage part divided into two 9 Lubricant

Claims (6)

[Claims] 1. A cleaning device for an image forming apparatus, comprising: a cleaning blade that presses against an image carrier to remove residual toner; and a hopper that temporarily stores toner scraped by the cleaning blade. A cleaning device for an image forming apparatus, wherein the cleaning device is divided into two parts and a powdery lubricant is stored in one storage part. 2. The image forming apparatus according to claim 1, wherein the hopper is located in a direction normal to the image carrier.
2. The cleaning device for an image forming apparatus according to claim 1, wherein the cleaning device is divided. 3. The cleaning device for an image forming apparatus according to claim 1, wherein a storage portion of the lubricant is on the image carrier side. 4. The cleaning device for an image forming apparatus according to claim 1, wherein said two-divided partition is in a net shape. 5. The cleaning device for an image forming apparatus according to claim 1, wherein an opening of the net is smaller than a particle size of the lubricant and larger than a particle size of the toner. 6. The method according to claim 1, wherein the lubricant is coated on a material having a higher specific gravity than the toner.
6. The cleaning device for an image forming apparatus according to any one of claims 1 to 5,