JP2000194242A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent residual toner from being stuck on paper even though the residual toner sticks to a paper powder removing means and scatters with respect to so-called cleaningless image forming device. SOLUTION: A seal 17 which is a flow-in stopping means is attached on the upstream side of a brush 16 in the rotating direction of a photoreceptive drum 11. The seal 17 is brought into press-contact with the surface of the photoreceptive drum 11 by prescribed pressure. The residual toner and paper powder pass through the seal 17, and the paper powder is removed by the brush 16 when it comes to the position of the brush 16. Then, though most of the residual toner passes through the brush 17, a little residual toner sticks to the brush 16. Toner stuck to the brush 16 is scattered by the vibration of a machine main body and the flow of air at the inside of a machine afterward. However, the seal 17 is provided between the brush 16 and a transfer part, so that the toner scattered is prevented from being dropped down on the paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image forming apparatus such as an electrostatic copying machine, a printer, a facsimile machine and the like. In particular, the present invention relates to a so-called cleaningless image forming apparatus in which a developer remaining after transfer is collected by a developing device.

[0002]

2. Description of the Related Art As a conventional electrostatic image forming apparatus, a developing roller is used to develop an electrostatic latent image formed on a photosensitive drum, and a contact developing method in which the developing roller is brought into contact with the photosensitive drum. Some have been adopted. Further, the developed toner image is transferred from the surface of the photosensitive drum to a sheet, and residual toner adheres to the surface of the photosensitive drum after the transfer. This residual toner is often collected by a cleaning device, but there is also a so-called cleaningless configuration in which the cleaning device is omitted.

FIG. 1 shows an outline of a so-called cleaningless image forming apparatus using a contact developing method using a developing roller. The photosensitive drum 1 is rotated at a constant speed in the direction of arrow 2. Around the photosensitive drum 1, a main charger 3, an exposure device 9, a developing roller 4, a transfer charger 5, and a brush 6 for removing paper dust are arranged along the rotation direction 2 of the photosensitive drum 1. The surface of the photosensitive drum 1 is charged to a predetermined potential by the discharge of the main charger 3. When the photosensitive drum 1 rotates in the direction of arrow 2, the charged surface is exposed by the exposure device 9 with light corresponding to an image. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 1. When the photosensitive drum 1 further rotates, the electrostatic latent image on the surface thereof comes into contact with the developing roller 4 and is developed by toner. When the toner image comes to a position facing the transfer charger 5, the toner image is transferred to the sheet that is sent. When the paper is transferred, the paper comes into contact with the surface of the photoreceptor, so that paper dust adheres to the surface of the photoreceptor drum. The photosensitive drum 1 having the paper dust adhered to the surface further rotates, and is removed by the brush 6 when the photosensitive drum 1 comes to the position of the brush 6 pressed against the photosensitive drum surface. The photosensitive drum 1 having passed through the brush 6 further rotates, and is again rotated by the main charger 3.
, The surface of the photosensitive drum 1 is charged to a predetermined potential by the main charger 3 for the next image formation. Further, the photosensitive drum 1 continues to rotate, and the exposure device 9
As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 1 by exposure, and when the developer reaches the position of the developing roller 4, the electrostatic latent image is developed into a toner image simultaneously with the recovery of residual toner. . As described above, the residual toner is
By so doing, a so-called cleaningless structure is realized.

[0004]

However, in the prior art as described above, the residual toner on the surface of the photosensitive drum 1 after the transfer adheres to the brush 6 without completely passing through the brush 6, and the residual residue There has been a problem that the toner scatters later and adheres to the surface of the paper, thereby adversely affecting the image. Further, in the case of the cleaningless structure, since the cleaning blade does not exist, the toner external additive such as silica sticks to the surface of the photosensitive drum during repeated copying, and a streak-like deposited layer is formed in the circumferential direction. This portion is charged lower than the surface potential of the other normal portion, and there is a problem that the image is adversely affected. Accordingly, the present invention is to provide an image forming apparatus employing a cleaningless system which has a simple structure and is effective to solve the above problems.

[0005]

According to a first aspect of the present invention, there is provided an image forming apparatus, comprising: a photosensitive member; a means for forming an electrostatic latent image on a surface of the photosensitive member; A developing unit for developing the electrostatic latent image with a developer, a transfer unit for transferring the developed image to a predetermined sheet, and a paper dust removing unit for removing paper dust on the photoconductor after the transfer. In an image forming apparatus in which a developer remaining on the surface of a photoreceptor after transfer is collected by the developing unit, a toner provided between the transfer unit and the paper dust removing unit is generated by the paper dust removing member. And a flow-in prevention means for preventing the scattering from flowing into the transfer means. According to the first aspect, the toner remaining on the paper dust removing unit does not scatter and adhere to the paper.

According to a second aspect of the present invention, there is provided the image forming apparatus according to the first aspect, wherein the flow-in preventing means is pressed against the surface of the photoreceptor. According to the second aspect of the present invention, since the flow preventing means is in pressure contact with the surface of the photoreceptor, it is possible to prevent an external additive such as silica from depositing on the surface of the photoreceptor. Accordingly, in the next image forming process, the surface of the photoreceptor can be uniformly charged by the main charger, and a problem-free image can be obtained.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the first or second aspect, wherein the inflow prevention means is attached to the paper dust removing means. According to the configuration of the third aspect, it is not necessary to separately prepare a member for attaching the inflow prevention means, so that an extremely simple configuration can be achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. The photosensitive drum 11 is rotated at a constant speed in the direction of arrow 12. Around the photoconductor drum 11, the main charger 1 is arranged along the rotation direction 12 of the photoconductor drum 11.
3. An exposure device 19, a developing roller 14, a transfer charger 15, and a brush 16 for removing paper dust are arranged. A seal 17 as a flow-in prevention means is attached to the brush 16 on the upstream side in the rotation direction of the photosensitive drum 11. The seal 17 is pressed against the surface of the photosensitive drum 11 at a predetermined pressure.

Next, an image process according to the present embodiment will be described. The surface of the photosensitive drum 11 is charged to a predetermined potential by the discharge of the main charger 13.
When the photosensitive drum 11 rotates in the direction of arrow 12, the charged surface is exposed by the exposure device 19 with light corresponding to an image. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 11. When the photosensitive drum 11 further rotates, the electrostatic latent image on the surface thereof comes into contact with the developing roller 14 and is developed by toner. Toner image is transferred charger 1
5 is transferred to the fed sheet. When the paper is transferred, the paper comes into contact with the surface of the photoreceptor, so that paper dust adheres to the surface of the photoreceptor drum. Also,
Since the toner image is not completely transferred to the sheet, residual toner adheres to the surface of the photosensitive drum 11. The photoreceptor drum 11 having the residual toner and the paper dust adhered to the surface further rotates, and the residual toner and the paper dust reach the seal 17 attached to the brush 16. At this time, since the residual toner and paper dust are electrostatically coupled to the surface of the photosensitive drum 11,
Without being scraped off by the seal 17
Pass through. Moreover, since the tip of the seal 17 is pressed against the surface of the photosensitive drum 11 with a predetermined pressure, it is possible to prevent the toner external additive such as silica from being deposited on the surface of the photosensitive drum 11. The material of the seal 17 is preferably urethane or polyethylene terephthalate having a thickness of about 0.1 mm, but is not limited thereto. Further, the photosensitive drum 11 keeps rotating, and when the photosensitive drum 11 reaches the position of the brush 16, the paper dust on the surface of the photosensitive drum 11 is removed by the brush 16. At this time, most of the residual toner passes through the brush 16, but some of the residual toner
6 adheres. The toner adhered to the brush 16 is scattered later due to the vibration of the machine main body or the flow of wind in the machine. However, since the seal 17 is provided between the brush 16 and the transfer unit, the scattered toner does not fall on the paper. When the photosensitive drum 11 that has passed through the brush 16 further rotates and faces the main charger 13 again, the surface of the photosensitive drum 11 is charged to a predetermined potential by the main charger 13 for the next image formation. At this time, since the external additive such as silica is prevented from being deposited on the surface of the photosensitive drum 11 by the seal 17, uniform charging is possible. Further, the photosensitive drum 11 continues to rotate, and exposure is performed by the exposure device 19, whereby an electrostatic latent image is formed on the surface of the photosensitive drum 11,
When the developer reaches the position of the developing roller 14, the electrostatic latent image is developed into a toner image simultaneously with the recovery of the residual toner.

In the embodiment described above, the contact developing system is described, but the present invention is not limited to this.
The present invention is also applicable to a so-called non-contact developing system in which the photosensitive drum and the developing roller are not in contact with each other. or,
As shown in FIG. 3, the brush 16 is composed of a base cloth 22 and a bristle foot 21. The bristle foot 21 is made of fiber such as rayon and cut to a length of several millimeters. Tens of thousands are woven around. However, the paper dust removing means according to the present invention is not limited to the one using the brush, and the same effect can be obtained by using, for example, a foaming roller or a brush roller.

[0011]

According to the first aspect of the present invention, even if the residual toner adhered to the paper dust removing means scatters, it does not adhere to the paper. According to the second aspect of the present invention, since the flow preventing means is in pressure contact with the surface of the photosensitive drum, it is possible to prevent the toner external additive such as silica from depositing on the surface of the photosensitive drum. Therefore, in the next image process, it is possible to uniformly charge the surface of the photosensitive drum by the main charger, and it is possible to obtain a problem-free image. According to the configuration of the third aspect, it is not necessary to separately prepare a member for attaching the inflow prevention means, so that an extremely simple configuration can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a conventional image forming apparatus.

FIG. 2 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a perspective view of a brush according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 photoconductor drum 13 main charger 14 developing device 15 transfer charger 16 brush 17 seal 19 exposure device

Claims (3)

[Claims] A photosensitive member; means for forming an electrostatic latent image on the surface of the photosensitive member; developing means for developing the formed electrostatic latent image with a developer; A transfer unit for transferring to the body, and a paper dust removing unit for removing paper dust on the photoreceptor after transfer, such that the developer remaining on the surface of the photoreceptor after transfer is collected by the developing unit. The image forming apparatus according to claim 1, further comprising a flow-in preventing means provided between the transfer means and the paper dust removing means for preventing toner scattering generated by the paper dust removing member from flowing into the transfer means. Image forming apparatus. 2. An image forming apparatus according to claim 1, wherein said flow preventing means is in pressure contact with a surface of said photosensitive member. 3. An image forming apparatus according to claim 1, wherein said flow preventing means is attached to said paper dust removing means.