Electrophotographic recording apparatus having a charging roller with a surface layer comprising a resin and a hardener
AssigneeOki Data Corporation
InventorAkihito Onishi
Life of this patent
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Abstract
An electrophotographic recording apparatus having a charging roller with a surface layer having a mixture of a resin and a hardener. The surface layer includes at least 10%, but less than 30%, by weight of the surface layer, of the hardener. This specific surface layer composition prevents the photosensitive drum, which is in contact with the charging roller, from becoming excessively charged. Furthermore, the amount of toner that adheres to the charging roller is reduced by circumferentially rotating the charging roller at a rate faster than the photosensitive drum.
Claims12
An electrophotographic recording apparatus comprising:
- a photosensitive drum having a rotation shaft;
- a charging roller for charging said photosensitive drum to a desired potential, said charging roller having a rotation shaft substantially parallel with the rotation shaft of said photosensitive drum and holding an external circumferential surface thereof in contact with said photosensitive drum, a ratio of a circumferential speed of said charging roller to a circumferential speed of said photosensitive drum being greater than 1, wherein said external circumferential surface of said charging roller is defined by a surface layer including a resin and a hardener, and wherein said hardener is included in said surface layer at a proportion of greater than or equal to 10 percent and less than or equal to 30 percent, by weight, of the surface layer.
An electrophotographic recording apparatus comprising:
- a photosensitive drum having a rotation shaft:
- a charging roller for charging said photosensitive drum to a desired potential, said charging roller having a rotation shaft substantially parallel with the rotation shaft of said photosensitive drum and holding an external circumferential surface thereof in contact with said photosensitive drum, a ratio of a circumferential speed of said charging roller to a circumferential speed of said photosensitive drum being greater than 1, wherein said external circumferential surface of said charging roller is defined by a surface layer including a resin a a hardener, and wherein said hardener is included in said surface layer at a proportion of greater than or equal to 10 percent and less than or equal to 30 percent, by weight of the surface layer,
- wherein an inclination angle when said charging roller, arranged slidably in the direction of the rotation shaft on a flat plate to be gradually inclined to the horizontal plane, starts to slide is in a specified range.
Dependencies are inferred from the claim text.