JP2001249553A - Roller transfer device and image forming device using the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller transfer device preventing the back surface of transfer paper from being soiled because of a situation that toner flows from both ends of a blade to the end and soils the inside of an image forming device. SOLUTION: In this roller transfer device 23 using a transfer roller 35 for transferring the toner to the transfer paper P, a cleaning blade 36 abuts also on the end cross section part 35a of the roller 35. Since the inside of the device 23 is not soiled, maintenance time is shortened and the back soiling of the transfer paper is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller transfer device used in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., in which a transfer roller is brought into contact with a transfer paper, pressed against a photoreceptor, and pressed on a photoreceptor. The present invention relates to a roller transfer device of a transfer roller for transferring the developed toner by an applied electric field.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, and a facsimile, an electrostatic latent image based on image data is formed on a photosensitive member. A developing device, a transfer device, and the like are provided around the photoconductor. The electrostatic latent image formed on the surface of the photoconductor is visualized as a toner image according to the electrostatic latent image by a developing roller provided in a developing device. The transfer roller as a transfer device is supported movably with respect to the photoconductor in accordance with the thickness of the transfer paper conveyed between the photoconductor and the state of the surface of the photoconductor. It is urged toward the photoreceptor so as to have a gap between the body peripheral surface and one transfer sheet. An electric field is applied to the transfer roller so as to transfer the toner on the photoconductor to the transfer paper, and the toner on the peripheral surface of the photoconductor is transferred onto the transfer paper supplied to the gap between the photoconductor and the transfer roller. The toner image is transferred by suction from the back surface.

Some of such transfer rollers include a cleaning device for removing toner, paper dust and the like attached to the surface. As the cleaning device, it is conceivable to provide a thin plate-shaped cleaning blade such that its tip is in pressure contact with the peripheral surface of the transfer roller. A transfer device has been proposed in which a cleaning blade is fixed to a toner collection box, and the toner collection box is arranged such that the tip of the cleaning blade is pressed against the peripheral surface of the transfer roller. (For example, JP-A-58-184153). Further, there has been proposed a cleaning blade in which an elastic blade is joined to a holder so that the tip of the cleaning blade is pressed against the peripheral surface of the transfer roller, and fine droplets of a release agent are dispersed in the cleaning blade (for example, there is proposed a cleaning blade). And JP-A-7-295453).

[0004]

FIG. 4 is a block diagram schematically showing a conventional roller transfer device. In any of the proposed transfer devices described above, the electrostatic latent image formed on the photoconductor is converted into a toner image by the developing device, and the toner image is temporarily transferred to the image carrier (intermediate transfer member) 19. After the transfer, for example, a plurality of toner images are superimposed on the intermediate transfer body 19 to form a color image, and then the formed toner image is transferred to the transfer paper P by direct contact from the back surface of the transfer paper P. In the image forming apparatus including the intermediate transfer member 19 and the transfer roller 35, when the toner image on the intermediate transfer member 19 approaches the transfer device 23, the blade pressure spring 38 is operated by the action of a solenoid (not shown). And the blade 36
Is brought into contact with the transfer roller 35. The toner remaining on the transfer roller 35 is removed, and the transfer roller 35 is cleaned. Thereafter, the toner image on the intermediate transfer body 19 and the transfer paper P
Simultaneously enter the transfer section, and the transfer roller 35
Then, the toner image on the intermediate transfer body 19 is transferred to the transfer paper P by applying pressure to the intermediate transfer body 19 from the back surface.

However, the untransferred toner remains on the intermediate transfer body 19 and is cleaned by a cleaning device to clean it. However, there is still residual toner that cannot be completely cleaned. When the remaining toner contacts the transfer roller 35 without passing through the transfer paper P, the toner is transferred to the transfer roller 35. The toner transferred to the transfer roller 35 is removed from the transfer roller 35 by an elastic blade 36 such as polyurethane. However, conventionally, the toner peeled off from both ends of the blade 36 flows to the end of the transfer roller 35, and when a certain amount of toner is accumulated, the toner is scattered, so that the inside of the image forming apparatus is soiled. As a result, there is a problem that the back surface of the transfer paper P becomes dirty as a result of soiling the transport system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a roller transfer device, in which toner flows from both ends of a blade to the ends, and the inside of the image forming apparatus is moved. An object of the present invention is to provide a roller transfer device that does not stain the transfer paper and the back surface of the transfer paper.

[0007]

According to a first aspect of the present invention, there is provided a roller transfer apparatus using a transfer roller for transferring toner onto transfer paper.
This is a roller transfer device in which the cleaning blade is also brought into contact with the cross section of the end of the transfer roller. According to a second aspect of the present invention, in the roller transfer device according to the first aspect, the cleaning blade that is in contact with a cross section of the end portion of the transfer roller is an extension of the cleaning blade that is in contact with the transfer surface of the transfer roller. This is a roller transfer device provided on a line. According to a third aspect of the present invention, in the roller transfer device according to the second aspect, the cleaning blade that is in contact with the transfer surface of the transfer roller is longer than the transfer roller and protrudes from the transfer roller. Is wider than the part in contact with the transfer surface of the transfer roller,
This is a roller transfer device that comes into contact with the cross section of the end of the transfer roller. According to a fourth aspect of the present invention, there is provided a photoconductor for forming an electrostatic latent image on a surface thereof, a developing device for visualizing the electrostatic latent image on the photoconductor with toner, and a developing device for visualizing the electrostatic latent image on the photoconductor. An image forming apparatus comprising: a transfer device that transfers a toner image onto transfer paper; and a fixing device that fixes the toner image on the transfer paper.
A transfer device is an image forming apparatus including the roller transfer device according to any one of claims 1 to 3.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG.
The image forming apparatus according to claim 4, further comprising a roller transfer device. This copying machine includes an image reading device 1, an image writing device 8, an image forming device 2, and a paper feeding device 30. The image forming apparatus 2 includes a photoconductor 9, developing devices 14 and 1.
5, 16, 17, roller transfer device 23 and fixing means 28
Mainly composed of Charging means 1 around photoreceptor 9
2. Developing devices 14, 15, 16, 1 including developer carrier
7, a roller transfer device 23 and a cleaning device 10 are arranged. The surface of the photoconductor 9 is irradiated with a laser beam from a laser driving device. The sheet feeding device 30 is installed on a side surface of the image forming apparatus 2, and the transfer sheet P in the detachable sheet feeding cassette is supported by a middle plate, and is pressed against the sheet feeding roller 25 via an arm by a spring (not shown). On the back side of the image forming apparatus 2, a power supply, a printed circuit board (engine driver board), and other electrical equipment and a control device, or a controller board (not shown) are housed. Further, a toner replenishing unit is provided near the developing devices 14, 15, 16, and 17.

When an image is formed by using such an image forming apparatus, first, the surface of the photosensitive member 9 is uniformly charged by the charging means 12 and then irradiated with a laser beam to form an electrostatic latent image. You. Developing devices 14, 15, 16, 17
A two-component developer composed of a toner and a carrier is accommodated in the inside, and the developer is carried on the surface of the developer carrying member, and is conveyed to a developing area opposed to the photosensitive member 9 to be formed on the photosensitive member 9. The toner image is formed by transferring to the electrostatic latent image. In the paper feeding device 30, the paper feeding roller 25 is rotated by a command from a control unit (not shown), and the transfer paper P at the uppermost position in the paper feeding cassette is transported to the downstream registration roller 26 while being double-fed by the separation pad. The roller transfer device 23 is synchronized with the toner image formed on the photoreceptor 9 at a timing synchronized with the toner image.
Transported to the side. The photoconductor 9 is transferred by the roller transfer device 23.
The transfer paper P on which the upper toner image has been transferred is further conveyed to the position of the fixing unit 28, and a heating roller 28-2 having a built-in heater and a pressure roller 28 pressed against the heating roller 28-2. −1, and is heated and pressed to fix the toner image. The transfer paper P on which the image is formed in this manner is thereafter discharged from the discharge outlet by the discharge roller onto the discharge tray unit 29 and placed.

Here, a roller transfer device of the present invention will be described.
FIG. 2 is a roller transfer device according to claims 1 to 3,
FIG. 5 is a side view illustrating a protruding portion of a blade that comes into contact with a cross section of an end of a transfer roller. FIG. 3 is a perspective view of the roller transfer device according to any one of claims 1 to 3, showing a protruding portion of the blade abutting on a cross section of an end portion of the transfer roller. The paper transfer roller 35 rotates in the direction of the arrow in FIG.
Send out. At this time, by applying a bias at a certain timing, the toner image on the intermediate transfer belt 19 can be transferred onto the transfer paper P. Since the transfer roller 35 may come into contact with the intermediate transfer belt 19, the intermediate transfer belt 1
9 may be stained by toner outside the image adhering to the surface. If the toner remains on the roller, the back surface of the transfer paper will be stained. For example, if a double-sided copy is made in this state, an abnormal image will result. Therefore, 36 blades are attached to a blade bracket 37 as a cleaning member for the roller, and the toner on the roller is removed by pressing the blade against the roller 35 by a pressure spring 38. However, the removed toner often flows toward the end of the roller, so that the saturated toner accumulated on the end of the transfer roller 35 may be scattered. In order to solve this problem, the blade 36 is extended to the end of the transfer roller 35, and the toner at the end of the roller is scraped off. FIG.
As shown in (1), the roller end 35a is cleaned by the protruding edge 36b of the blade. The protruding portion 36a of the blade cleans the roller end 35a and at the same time prevents the toner from scattering from the roller end.

[0011]

As described above, in the roller transfer device according to the first and second aspects, since the inside of the roller transfer device is not stained, the maintenance time can be reduced, and the back of the transfer paper can be achieved. Dirt can be prevented. In the roller transfer device according to the third aspect, the cost can be reduced by integrating the blade for cleaning the transfer roller and the blade for cleaning the cross section of the end portion of the transfer roller. In the image forming apparatus according to the fourth aspect, since the inside of the roller transfer device is not stained, it is possible to obtain a clean image of the transfer sheet discharged from the fixing device.

[Brief description of the drawings]

FIG. 1 is an image forming apparatus according to claim 4, comprising the roller transfer device according to any one of claims 1 to 3;

FIG. 2 is a roller transfer device according to claim 1, wherein
FIG. 5 is a side view illustrating a protruding portion of a blade that comes into contact with a cross section of an end of a transfer roller.

FIG. 3 is a roller transfer device according to claim 1, wherein
FIG. 4 is a perspective view illustrating a protruding portion of a blade that comes into contact with a cross section of an end portion of a transfer roller.

FIG. 4 is a configuration diagram schematically showing a conventional roller transfer device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 reading device 2 image forming device 8 writing device 9 photoconductor 12 charging device 14, 15, 16, 17 developing device 19 intermediate transfer belt 23 roller transfer device 28 fixing device 35 transfer roller 35a transfer roller end section 36 blade 36a Blade protruding portion 36b Blade protruding portion edge portion 37 Blade blanket 38 Blade pressurizing spring 39 Guide below entrance

Claims (4)

[Claims] 1. A roller transfer device using a transfer roller for transferring toner onto transfer paper, wherein a cleaning blade is also brought into contact with a cross section of an end portion of the transfer roller. 2. The roller transfer device according to claim 1, wherein the cleaning blade abutting on the cross section of the end of the transfer roller is provided on an extension of the cleaning blade abutting on the transfer surface of the transfer roller. A roller transfer device, characterized in that: 3. The roller transfer device according to claim 2, wherein the cleaning blade that is in contact with the transfer surface of the transfer roller is longer than the transfer roller and a portion protruding from the transfer roller is transferred to the transfer roller. A roller transfer device having a width wider than a portion in contact with the transfer surface of the transfer roller and abutting on a cross section of an end portion of the transfer roller. 4. A photoreceptor for forming an electrostatic latent image on a surface thereof, a developing device for developing the electrostatic latent image on the photoreceptor with toner, and transferring the visualized toner image on the photoreceptor. An image forming apparatus comprising: a transfer device for transferring to a sheet of paper; and a fixing device for fixing a toner image on the transfer sheet, wherein the transfer device is the roller transfer device according to claim 1. Image forming apparatus.