A charging unit is provided, the charging unit including: a charging member; and a charging member clean-up member having an elastic layer, the elastic layer containing a silicon oil, wherein a silicone concentration in analyzing the charging member by an x-ray photoelectron spectroscopy satisfies following condition: about 1 atm %\u2266\u2266about 3 atm %. The systems and methods may be implemented using the Internet or another information retrieval system that includes a client system and a remote server. Windings are wound such that the polarities of output voltages on output windings wound around a row of three or more stator magnetic poles will be the same; all of the output windings are divided into an even number, two or greater, of groups, and output windings are serially connected in such a way that adjacent group output voltage polarities mutually differ. In one embodiment, the seam-defining structure is a narrow elongated structure configured to define an exteriorly invisible tear seam generally corresponding with portions of an outline of the door structure, and the inner layer has a reduced thickness portion along the exteriorly invisible tear seam by virtue of the presence of the narrow elongated structure. A lower end of the first slope of the emitter enters the recess portion, and both the first slope and the second slope of the emitter tilt to an outside of the recess portion.