JPS6215821Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cleaning device for an image forming apparatus to which electrophotography is applied. More specifically, the present invention relates to a web cleaning device.

Generally, in an image forming apparatus using electrophotography such as an electrophotographic copying machine, an image carrier having a photoconductive layer is formed into a drum shape, and a copy image of a document is created by rotating the image carrier. do. In the above device, an electrostatic latent image is formed according to the original image by arranging a charging means, an exposing means, and a developing means around a rotating image carrier, and this electrostatic latent image is developed with toner particles. Do this. The developed image on the image carrier is then electrostatically transferred to a transfer material such as paper, and the developed image is fixed and utilized on the transfer material. On the other hand, after the image carrier is transferred, residual developer is removed by a cleaning device.
Prepare for the next copy image formation.

Conventionally, a web cleaning device has been used as one form of the cleaning device. This web cleaning device presses a web such as cloth against an image carrier and rubs away developer remaining on the image carrier. Therefore, in order to always bring a new web surface into pressure contact with the image carrier and maintain a constant cleaning ability, the web must be fed at a constant speed. Further, when the entire amount of web is used up, the web must be replaced, and therefore it is desirable to minimize the amount of web feeding.

Therefore, in conventional web cleaning devices, the amount of web feed is controlled by the amount of rotation of a roller for pressing the web against an image carrier or a roller for winding up a used web.
However, in the former case where the feed amount is controlled by a roller for pressing the web against the image carrier, the distance between the image carrier and the web, or the web and the roller may vary depending on the surface condition of the image carrier. The difference in the frictional force between the two tends to fluctuate, and as a result, the amount of web feed may not be constant. Furthermore, if this variation in frictional force occurs locally on the contact surface, wrinkles may occur in the web, eventually resulting in poor cleaning. In addition, when controlling the feed amount using the latter web take-up roller, there is a drawback that the feed amount changes because the outer diameter of the roller changes as the web is wound, and there is a mechanism to compensate for this. More is needed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a web cleaning apparatus that solves the problems of the conventional web cleaning apparatus and easily achieves stable feeding of a small amount of web. Still another object of the present invention is to provide a web cleaning device that prevents wrinkles from occurring during the web feeding process.

In order to achieve the above object, the present invention has the following configuration. That is, in a web cleaning device that uses a web to rub and clean the surface of an image carrier on which deposits remain, a first roller having an elastic surface that presses the web against the surface of the image carrier; A second roller that presses the web against the first roller on the downstream side in the web feeding direction from the pressed position, and a drive source that applies a driving force to at least one of the rollers. This is a web cleaning device with special features.

Hereinafter, the present invention will be explained in detail using FIGS. 1 and 2. FIG. 1 is a side view of the web cleaning device of the present invention, and FIG. 2 is a perspective view thereof.

In FIG. 1, an image carrier 2 is rotatably held around an axis 1. As shown in FIG. Also, web 1 such as cloth
A pressing roller 5, which is a first roller for pressing 0 onto the image carrier surface 3, is rotatably disposed about a shaft 4. Further, a second roller according to the present invention, roller 7, is in pressure contact with roller 5 via web 10. As is clear from the figure, the pressure contact position is downstream in the feeding direction of the web 10 from the position where the web 10 is pressed against the image carrier surface 3. This roller 5 is rotatable around an axis 6. Further, gears 8 and 9 are fixed to the shafts 4 and 6, respectively, and drive force is obtained from a drive device M to rotate the rollers 5 and 7.

Here, the image carrier 2 rotates clockwise. In order to remove the residual developer adhering to the surface 3 of the image carrier, the web 10 is fed out from a web feeding device (not shown) and transferred to a roller 5 that rotates clockwise. The image bearing member surface 3 is pressed against the image carrier surface 3 by. The web 10 that has been pressed against the image carrier surface 3 and has had the residual developer rubbed off from the surface is then sandwiched between rollers 5 and 7 and wound up by a web winding device (not shown). . Here, the roller 5 has an elastic surface, and by adjusting the distance from the image carrier surface 3, the contact pressure and contact width (i.e., contact time) of the web 10 to the image carrier surface 3 are controlled. It works like this. Further, the roller 7 works together with the roller 5 to control the feed amount of the web. This effect will be explained in more detail. The force acting on the moving web 10 is caused by the force acting on the image carrier surface 3 and the web 1.
The sliding friction force A between 0 and roller 5 and web 1
0, and the static friction force C between the rollers 5, 7 and the web 10. Therefore, when there is no roller 7 as in a conventional web cleaning device, the difference between the sliding friction force A between the image carrier surface 3 and the web 10 and the static friction force B between the roller 5 and the web 10 is The amount will be controlled. However, as mentioned above, the state of the image carrier surface 3 is likely to change depending on the residual state of developer, atmospheric conditions, etc., and therefore the sliding friction force A
Also, the amount of feed of the web 10 may not be constant, or the web 10 may be wrinkled. Therefore, by providing the roller 7 according to the present invention and setting C>>B-A, the feed amount of the web 10 can be controlled by the cooperative action of the rollers 5 and 7. In other words, even if the difference between A and B changes and the web feed rate changes, by increasing the static friction force C between the rollers 5, 7 and the web 10, static friction without friction fluctuation can be achieved. Since the amount of web feed can be controlled by the force C, the web can be reliably fed at a constant speed.

Next, the drive system of this device will be explained in detail. 1st
As shown in the figure, shafts 4 and 6 are connected to gears 8 and 6, respectively.
9, and when the two gears mesh, 2
If power transmission between shafts is possible, any gear may be connected to the drive device M. Also, roller 5
It is also possible to drive only the roller 7 and follow the roller 7, in which case only the gear 8 is connected to the drive device M , and the gear 9 becomes unnecessary. In this case roller 7
may be arranged so that a constant frictional force is generated by pressing the web 10 against the roller 5. Note that in this embodiment, roller 5 and roller 7
Sponge rubber and nitrile rubber were used for the surfaces, respectively.

As described above in detail, the present invention includes, in addition to the pressure roller that presses the web against the image carrier, a roller that comes into pressure contact with the pressure roller via the web. By making the static frictional force between the pressing roller and the web larger than the difference between the sliding frictional force between the surface of the image carrier and the web and the static frictional force between the pressing roller and the web, the pressing roller The feed amount of the web is controlled by the pressing force between the roller and the roller. In other words, the web cleaning device according to the present invention has the function of pressing the web against the image carrier and the function of feeding the web in a minute amount independently, thereby ensuring that the web is fed at a minute constant speed and preventing wrinkles on the web. Moreover, it is possible to prevent the web from being fed obliquely.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a web cleaning device to which the present invention is applied, and FIG. 2 is a side view thereof. In the figure, 1, 4, 6... shaft, 2... image carrier, 3... image carrier surface, 5... pressure roller, 7... roller,
8, 9...gear, 10...web.

Claims (1)

[Claims for Utility Model Registration] A web cleaning device that uses a web to rub and clean the surface of an image carrier on which deposits remain, comprising: a first roller having an elastic surface that presses the web against the surface of the image carrier; a second roller that presses the web against the first roller on the downstream side in the web feeding direction of the position where the web is pressed against the carrier surface; and a drive source that applies driving force to at least one of the rollers. A web cleaning device comprising: