JPS6194081A - Cleaning device - Google Patents

Abstract

PURPOSE:To maintain a stable rubbing effect over a long period of time and to obtain an image having good quality by using a tough material to constitute part of a scraper, which contacts with an elastic rubbing roller, at least near the contact edge thereof. CONSTITUTION:An elastic cleaning blade 3 of which the end edge is in press contact with a photosensitive body 1 and the elastic rubbing roller 4 having an outside layer 4a consisting of a silicone rubber layer and an inside layer 4b consisting of silicone sponge are disposed to a cleaning device 2 in an image forming device such as an electrophotographic copying machine for which an electrostatic transfer process is utilized. The toner and other foreign matter removed from the surface of the body 1 by the blade 3 and the roller 4 stick and deposit on the surface of the roller 4, are conveyed according to the rotation thereof and are scraped by a scraper 5 and thereafter the toner, etc. are discharged to the outside of the cleaning device by a screw conveyor 6. At least the contact edge of the scraper 5 with the roller 4 and the part near the same are formed of a ceramic material. The durability is thus remarkably improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus using an electrostatic transfer process, such as an electrophotographic copying machine, and a cleaning apparatus therefor.

(Prior art and issues to be solved) After forming a transferable toner image on the surface of an endlessly running image carrier and transferring it to a transfer material, the process of cleaning the image carrier surface is changed. In well-known image forming apparatuses, a cleaning blade made of an elastic material such as urethane has been widely used in order to remove residual toner remaining on the surface of an image carrier after transfer.

However, although such a leaning blade has a simple structure and an excellent toner removal function, it may produce corona products due to corona discharge from a high-pressure member present in an image forming device, or the paper used mainly as a transfer material. It is not necessarily suitable for removing precipitates such as talc and rosin deposited on the surface of the image carrier. This kind of foreign matter absorbs moisture in the atmosphere and lowers the resistance of the area on the surface of the image carrier to which it is attached, which may cause disturbance of the electrostatic latent image. Unless removed, image quality deterioration cannot be avoided.

For this reason, recently, a method has been proposed in which the above-mentioned foreign matter is removed by rubbing a σ-ra made of an elastic material such as silicone rubber or urethane rubber on the image carrier.

When using this type of elastic rubbing roller, foreign matter such as toner, corona products, etc. that have been removed from the surface of the image carrier and adhered to the roller may return to the image carrier and adhere to the roller. A scraper is brought into contact with the surface of the roller to remove toner and other foreign matter. Conventionally, plates made of metal materials such as Mylar (trade name), stainless steel, phosphor bronze, and aluminum have been used as scrapers for this purpose, but all of these materials are susceptible to wear. The scraping action on the rubbing roller quickly deteriorates, and the toner adheres more firmly to the surface of the image carrier than is removed from the rubbing roller, damaging the surface of the image carrier. The scraper edge was locally worn and became saw-toothed, which caused damage to the surface of the rubbing roller.9 This was largely avoided.

The present invention has been developed in view of the current situation, and has a stable function over a long period of time by constructing at least the vicinity of the contact edge of the scraper that contacts the elastic rubbing roller with a strong material. The purpose is to obtain a cleaning device.

(2) Structure of the invention (Technical means 2 to solve the problem) In order to achieve the above object, the present invention includes a cleaning device equipped with an elastic rubbing roller for rubbing off toner and other foreign substances. The device is characterized in that the portion of the scraper that comes into contact with the rubbing roller is made of a ceramic material.

With this configuration, the scraper maintains its scraping action over a long period of time, and thereby the rubbing function of the rubbing roller against the image carrier can be maintained.

(Description of Embodiments) The attached drawings show an embodiment in which the present invention is applied to a copying machine equipped with a rotating cylindrical photoreceptor.

In FIG. 1, reference numeral 1 indicates a photoreceptor, which rotates in the direction indicated by the arrow.

A cleaning group 2 is disposed at a predetermined position close to the photoreceptor l.

Around the photoreceptor l, there is a charger for charging the surface photoconductive layer, a latent image forming area for projecting an optical image of the original onto the charger to form an electrostatic latent image, and a toner for applying toner to the electrostatic latent image. The members necessary for image formation, such as a development section that applies toner to form a transferable toner image and a transfer section that is equipped with a transfer charger to transfer the toner image to a transfer material, are arranged. Since they are not directly related to the present invention, their explanation will be omitted.

At the above-mentioned transfer site, the residual toner remaining on the surface of the photoreceptor without contributing to the transfer reaches the cleaning device 2 as the photoreceptor 1 rotates.

The cleaning device includes a device extending in the axial direction of the photoreceptor l,
An elastic cleaning blade 3 whose one edge is in pressure contact with the photoconductor, and an elastic rubbing roller 4 disposed upstream of the cleaning blade when viewed in the direction of travel of the photoconductor are disposed. There is.

The elastic rubbing roller 4 consists of an outer layer 4a made of a solid silicone rubber layer and an inner layer 4b made of a silicone sponge, and has a hardness of 20 to 40 (ASKERC constant load 5).
00 Pr), and when the relative running speed with respect to the photoconductor at the contact area with the photoconductor was set to 50 to 300, a good rubbing action was obtained, but of course this is limited to such a device. It is not something that will be done.

Toner and other foreign substances removed from the surface of the photoconductor by the cleaning blade 3 and the rubbing roller 4 adhere to and accumulate on the surface of the roller, are conveyed as the roller rotates, are scraped off by the scraper 5, and then transferred to the screw conveyor 6. shall be discharged from the cleaning device.

In such a device, in the present invention, at least the abutting edge of the scraper 5 against the rubbing roller and the vicinity thereof are formed of a ceramic material.

FIGS. 2 and 3 are enlarged views showing the vicinity of the rubbing roller 4 and scraper 5. FIG.

In FIG. 2, dispersion nickel plating 5c coated with SIC of high hardness (I (mv2500)) is applied to the edge of a scraper base material 5d made of stainless steel.

FIG. 3 shows the scraper 51 made entirely of ceramic material.

The following table shows the results of testing the durability of the scraper shown in Figure 2.

As can be readily seen from this table, it can be seen that the durability is greatly increased by using the scraper according to the present invention.

(3) Effects of the Invention Since the present invention has the configuration described above, the scraper that comes into contact with the rubbing roller suffers little wear, and a stable rubbing effect can be obtained over a long period of time, so that it is possible to provide a stable rubbing effect on the image carrier. This greatly contributes to avoiding adverse effects and obtaining high-quality images.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the main parts of an embodiment in which the present invention is applied to a copying machine, FIG. 2 is an enlarged side view showing a rubbing roller and a scraper, and FIG. 3 is another embodiment of the same. FIG.

Claims (1)

[Scope of Claims] An elastic sliding roller that presses against and slides against the surface of the image carrier, and a scraper that comes into contact with the surface of the sliding roller, the edge of which the scraper contacts the sliding roller. A cleaning device whose surface is made of ceramic material.