JPH0412524Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement of a cleaning roll.

[Prior Art] FIG. 3 shows a typical usage example of a cleaning roll. The cleaning roll 10 rubs and removes residual magnetic developer 12 on the photosensitive drum 11 when it rotates in contact with the circumferential surface of the photosensitive drum 11 .
At this time, the cleaning roll 10 comes into contact with the cleaning blade 13 in order to scrape off the residual magnetic developer 12 from its peripheral surface, and the surface layer 14 is charged due to friction. Therefore, the material of the surface layer of the cleaning roll 10 is determined in consideration of the material of the surface of the photosensitive drum 12 and the material of the surface layer 14 of the cleaning blade 13, and the material of the surface layer of the cleaning roll 10 is determined, and the charge of the polarity opposite to that of the residual magnetic developer 12 is determined. The surface layer 1
It has a tinge of 4. As a result, in addition to the mechanical rubbing action, the residual magnetic developer 12 is removed from the photosensitive drum 11 by an electrical adsorption action.

Conventionally, as a means of removing residual magnetic developer (toner) adhering to the surface of the photosensitive drum of an electrophotographic copying machine, a cleaning method in which a surface coating layer made of resin or rubber is formed on the circumferential surface of a core metal via a sponge layer. roll is used. This cleaning roll charges the surface coating layer through friction as it rotates in contact with the circumferential surface of the photosensitive drum, and removes residual magnetic developer by the action of the electric charge (attractive force caused by the electric charge). I'm starting to do that.

[Problem to be solved by the invention] However, since this cleaning roll has a high hardness on the roll surface, if a large foreign object enters between the photosensitive drum and the cleaning roll, the foreign object may be inserted between the photosensitive drum and the cleaning roll. Another problem was that the surface of the photosensitive drum was damaged when the photosensitive drum rotated.

[Means for Solving the Problems] This invention is a cleaning roll characterized in that a surface coating layer is formed on the circumferential surface of a core metal via a soft magnetic sponge layer.

In this invention, the magnetic sponge layer is
Any sponge material made from general rubber or plastic that contains a substance that generates magnetic force, such as ferrite, will suffice, but if you use a soft magnetic sponge, the cleaning roll will be harder. As a result, the effect of preventing damage to the surface of the photosensitive drum is reduced. Therefore,
In this invention, it was decided to use a soft (for example, 40 degrees or less on the Asker type C hardness tester) magnetic sponge layer.

In this invention, the surface coating layer is preferably made of a material that does not contain substances that would contaminate the photosensitive drum upon contact with the photosensitive drum, and that is highly effective in removing residual magnetic developer using the attraction force generated by the electric charges. Specifically, urethane rubber, nylon resin, fluororesin, etc. are used, but when using hard materials, the thickness of the surface coating layer should be several tens to hundreds of microns so as not to increase the hardness of the cleaning roll. Therefore, it is desirable to reduce the hardness of the cleaning roll.

In this invention, the magnetization treatment of the magnetic sponge layer can be easily performed using a commercially available magnetization device. Further, the amount of magnetization is desirably set appropriately depending on the type, amount, etc. of the residual magnetic developer to be removed.

When a cleaning roll having the above-mentioned soft magnetic sponge layer is used, in addition to the rubbing action by the surface of the cleaning roll and the electrical attraction action by the charging of the surface coating layer, the attraction action by the magnetic force of the magnetic sponge layer also occurs.

On the other hand, since the residual magnetic developer contains a substance that is attracted by magnetic force, it is more strongly attracted to the cleaning roll. Therefore, cleaning defects caused by residual magnetic developer once scattered during cleaning of the photosensitive drum surface being adsorbed onto the photosensitive drum surface again are eliminated, and the residual magnetic developer can be completely removed.

[Function] According to the cleaning roll of this invention, since the residual magnetic developer is removed by the action of the soft magnetic sponge layer whose surface is covered with a surface coating layer, there is no possibility of foreign matter getting between the photosensitive drum and the roll. Also, since the hardness of the roll surface is low, the roll surface deforms so that foreign matter bites into the roll surface (surface coating layer). This state is as shown in FIG. 4, where S and N indicate the magnetized state in the magnetic sponge layer. Therefore, the pressing force of the foreign matter on the photosensitive drum becomes weaker than in the conventional case, making it less likely to be scratched. Further, by setting the magnetic force of the magnetic sponge layer to a predetermined value, residual magnetic developer can be completely removed.

[Example] Hereinafter, an example of this invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a schematic perspective view of a cleaning roll according to an embodiment of this invention, and FIG. 2 is a sectional view taken along - in FIG. 1.

First, prepare a core metal with a diameter of 10 mm. This core metal 1
Sponge raw materials with the following composition were applied to the circumferential surface of the roll using an adhesive, foamed with hot air, and the surface was polished to obtain a roll with a diameter of 16 mm having a sponge layer on the surface. .

(Sponge raw material) Base polymer (silicone rubber) KE903FU 100 parts by weight Crosslinking agent (C-1) 1.0 parts by weight Crosslinking agent (C-3) 3.0 parts by weight Foaming agent KE-P-13 5.0 parts by weight r-ferrite 100 parts by weight In addition, the above KE903FU, C-1, C-3, and
KE-P-13 is a trade name of Shin-Etsu Chemical Co., Ltd.

Next, a surface coating layer made of urethane rubber was formed on the circumferential surface of the sponge layer to obtain a roll having a diameter of 17 mm. After that, this roll was subjected to magnetization treatment using a magnetization device HD-100 model (manufactured by Denshi Magnetic Industry Co., Ltd.).
As shown in FIGS. 1 and 2, a cleaning roll 10 was obtained in which a surface coating layer 3 was formed on the circumferential surface of a core bar 1 via a magnetized sponge layer 2.

When this cleaning roll 10 was used to remove residual magnetic developer on the surface of an electrostatic copying machine NP-150Z (trade name of Canon Inc.), it was found that the residual magnetic developer did not damage the photosensitive drum at all. The agent could be completely removed. Here, the photosensitive drum was not damaged because the sponge raw material contained a foaming agent (trade name: KE-P-13) manufactured by Shin-Etsu Chemical Co., Ltd. This is because No. 2 exhibited softness. The degree of softness of the magnetic sponge layer changes depending on the amount of the foaming agent blended, but in this example, it is about 40° on the ASKER C-type hardness tester. A degree of softness below this value is desirable in order to avoid damage to the photosensitive drum.

[Effects of the invention] As described above, according to the cleaning roll according to the invention, residual magnetic developer on the surface of the photosensitive drum can be reliably removed while preventing scratches from occurring on the photosensitive drum.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view of a cleaning roll according to an embodiment of this invention, and Fig. 2 is a -
FIG. 3 is an explanatory diagram showing a general usage example of the cleaning roll, and FIG. 4 is a conceptual diagram for explaining the action of the cleaning roll according to the present invention. 1...Core metal, 2...Magnetic sponge layer, 3
...Surface coating layer, 10...Cleaning roll.

Claims (1)

[Scope of utility model registration request] A cleaning roll characterized in that a surface coating layer is formed on the circumferential surface of a core metal via a soft magnetic sponge layer.