Abstract: In the paper feeding roller, a shaft body has a cantilever structure supported at one end, and an elastic layer includes a supported end and a free end on both ends along a rotation axis, wherein an outer diameter of the free end in a cross section orthogonal to the rotational axis is greater than that of the supported end, and an area including the free end has a widened bottom part having an outer diameter which widens in a linear or inner convex manner approaching the free end along the rotation axis. The paper feeding device includes a feed roller rotationally driven and conveying paper, and a retard roller pressed against the feed roller, affixed with a torque limiter, and suppressing double feeding of paper. At least one of the feed roller and the retard roller is formed as the paper feeding roller.

Abstract: A conductive roll sequentially has a conductive layer of an elastic material, a resistance adjusting layer, and a protective layer which are formed on an outer periphery of a shaft. The resistance adjusting layer is formed from a composition containing 10 to 150 parts by weight of an electron conductive agent, not more than two parts by weight of an ion conductive agent and 20 to 80 parts by weight of an insulating filler, relative to 100 parts by weight of nitrile rubber, or nitrile rubber hydride as a base material. The roll has a properly controlled environment dependence of its electric resistance, and avoids any trouble, such as enlarged picture defects, when employed in an electrophotographic process.

Abstract: A charging roll which is held in contact with an outer circumferential surface of an image bearing medium for charging the surface of the image bearing medium by application of a DC voltage and an AC voltage which is superimposed on the DC voltage, the charging roll comprising: a center shaft; an electrically conductive base layer formed on an outer circumferential surface of the shaft; an outer structure formed on an outer circumferential surface of the conductive base layer; and the charging roll having Asker C hardness of less than 48 degrees as measured upon application of 1 kg load thereto and micro rubber hardness in a range of 65-85 degrees as measured upon application of 33.85 g load thereto.