JPH0137738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blade device in which an elastic blade that comes into contact with a moving body is adhesively supported by its support member using an adhesive.

Conventionally, in image forming apparatuses such as electrophotographic apparatuses, a developed image is formed on the surface of an image carrier such as a photoreceptor,
After the transfer, the surface is cleaned and reused. For example, in an electrophotographic copying machine, first,
A light image corresponding to the original is projected onto a photoconductive photosensitive layer provided on the circumferential surface of the drum to form an electrostatic latent image, and then a toner image is formed by attaching a developer to this latent image. Ru. Furthermore, the transfer material is pressed against the photosensitive drum, and the image on the drum is transferred.
Finally, this is fixed and a copy is created. After transfer, the drum is cleaned of residual toner by a cleaning device and is ready for the next image formation. As a cleaning device, there has conventionally been a blade cleaning method. In this method, a wear-resistant rubber material is usually brought into pressure contact with the surface of the photoreceptor, and the toner remaining on the surface of the photoreceptor is removed by friction at the edge of the rubber material. The device based on this method has a simple structure and can be made compact, so it is very useful as a cleaning device for electrophotographic copying machines.

The present invention provides a simple and effective blade device in which the elastic blade as described above is supported by its support member.

The conventional holding method is to sandwich the rubber between two members, for example as shown in Figure 1, but if the thickness of the rubber varies, the amount of tightening may be too large, causing waves on the blade. It may occur or become so weak that it may fall off easily.

In order to prevent this, it was necessary to control the tightening pressure and the amount of pinching.

The function of such a holding member is to hold the blade so that it does not fall off even if an external force is applied to the blade or it vibrates, so if it can be fixed to one side of the holding member with adhesive etc., it can be sandwiched between the two members. There is no need for this, and the goal can be easily achieved.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In the present invention, the surface of the elastic blade that contacts the movable body is adhesively supported by the supporting member of the elastic blade, and this configuration is effective in the following cases.

When molding this type of blade, centrifugal molding is usually used. This involves injecting a prepolymer into the inner surface of a cylindrical mold drum, causing a reaction while rotating the drum, and molding a sheet-like rubber that adheres closely to the cylindrical inner surface. In this molding method, in order to improve the release of the molded rubber sheet from the mold, the inner surface of the mold is roughened or a release agent is applied.

Further, since the surface area of the blade is better on the side opposite to the side in close contact with the mold, this side is used as the abutting surface against the photoreceptor during use. Therefore, by using the same surface as the contact surface as the adhesive surface with the holder, the surface coated with the mold release agent can be avoided. (Adhesive strength decreases on the release surface side.) Recently, copier bodies have become smaller and lower cost is required, so the length of the blade may be shortened. In this case, the free length becomes relatively short, and unless the amount of deflection is reduced, the permanent strain of the blade will increase, which is undesirable. Therefore, in order to reduce the amount of deflection, it is desirable to position the blade more accurately.

By using the drum contacting surface as the fixed surface, it is not affected by the tolerance of the rubber plate thickness, and since the same surface as the fixed surface is the drum contacting position, it is easy to achieve positional accuracy.

Particularly, when the photosensitive drum rotates in the counter direction (clockwise direction in the figure), the blade holding force is advantageous because the drum tangential component of the force applied to the tip of the blade is directly received by the holder surface. (Figure 3) If the frictional force between the photosensitive drum and the blade becomes excessively large, the tip of the blade may be dragged by the rotation of the drum, causing the phenomenon of "blade turning." This phenomenon is less likely to occur.

As described above, the present invention provides a blade device having a simple structure and low cost, which facilitates the positional accuracy of the elastic blade and prevents the elastic blade from turning over.

As for the adhesive, SBR rubber sheet adhesive gave good results in both adhesive performance and workability.

Further, in the figure, 1 is a photosensitive drum, and 3 is a rubber blade. The toner remaining on the photosensitive drum is scraped off by the rubber blade 3, and the toner located below it is made of polyester with a thickness of about 75 μm. It is stored in a container using a scooping sheet 7 made of film. This scooping sheet 7 is in light contact with the surface of the drum 1, and the degree of contact is such that the residual toner can pass through this sheet.

This contact of the sheet 7 with the drum prevents the toner scraped off by the blade 3 from leaking from inside the container to the outside. Reference numeral 8 at the bottom of the cleaning device is a magnet for collecting toner that has fallen to the outside.

A part of the interior of this cleaning device is partitioned by a fixed partition plate 10, and the toner dropped by the blade 3 as described above is pushed into a space 11 at the back of the container by a rotating scraping member 9. By doing so, the apparent density of the toner can be increased and the container can be made smaller. The scraping member 9 is made of an elastic body such as a polyester sheet or cloth impregnated with rubber.

Although the drum contact position of the cleaning blade was explained above in the so-called counter direction, the object of the present invention can be achieved even if the contact position of the blade 3 to the drum 1 is in the forward direction with respect to the drum movement direction, as shown in FIG.
The effect and action are the same.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional cleaning device, and FIGS. 2, 3, and 4 are sectional views of a cleaning device using an embodiment of the present invention. 1...Photosensitive drum, 3...Rubber blade, 7...
...scoop sheet.

Claims (1)

[Claims] 1. In a blade device having an elastic blade that contacts a moving body and a support member that adhesively supports the elastic blade with an adhesive, the side of the elastic blade that contacts the moving body is adhered to the support member. A blade device characterized by: