Developing roller of electrophotographic device without prone to scumming in a nonprinting area
AssigneeBando Chemical Industries, Ltd.
InventorsTaku Yamoto, Kimiya Goto, Hideki Norisada
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Abstract
The purpose of the present invention is to provide a developing roller which is not prone to scumming in a nonprinting area. The solution is to provide a developing roller which has an elastic layer, a coat layer formed on the elastic layer, and end portion coat layers formed on outermost surfaces on two axial end portions, wherein the end portion coat layer contains a conductive material.
Claims7
A developing roller having two end portions and a central portion disposed between the two end portions in an extension direction of an axial, comprising an elastic layer, a coat layer formed on the elastic layer, and end portion coat layers only formed on outermost surfaces on the two end portions, wherein
- the end portion coat layer comprises a conductive material,
- a ratio (Ω1/Ω2) of a resistance value Ω1 at an axial central part of the end portion coat layer to a resistance value Ω2 at an axial central part of the coat layer is 1.6 or less, and
- an absolute value (|Ω1−Ω2|) of a difference between the resistance value Ω1 at the axial central part of the end portion coat layer and the resistance value Ω2 at the axial central part of the coat layer is 0.7 GΩ or less.
Dependencies are inferred from the claim text.