Sharp Kabushiki Kaisha Corporation

Keizo Kitamura

Takahiro Bito

Hitoshi Nagahama

Toshihisa Ishida

Syouichi Fujita

Mitsuhiro Hasegawa

Tadayuki Sawai

Kouichi Takenouchi

Katsuaki Sumida

Teruhiko Noguchi

Ken Yamagishi

Yukihisa Imaue

Katsushi Inoue

Tomoko Mamemoto

Tatsuya Itou

A magnetic member is arranged at a position on the downstream side with respect to the rotational direction of a developing sleeve, outside the developer conveyance path where the magnetism from the magnetic member has no influence on the magnetic field of the developing magnetic pole. When the magnetic member is arranged with its N pole facing the developing sleeve, the magnetic attractive force from the magnetic member weakens the developer's attraction to the peripheral surface of the developing sleeve. When the magnetic member is arranged with its S pole facing the developing sleeve, the developer being conveyed along the developer conveyance path is magnetized in such a direction as to repel the peripheral surface of the developing sleeve. In either case, the adhering state of the developer to the peripheral surface of the developing sleeve having passed through the developing position is unstable, so that the developer having adhered to the developing sleeve will easily drop off from the developing sleeve after passage of the developing position.

Electrophotographic developing unit

An image forming apparatus includes (i) a photosensitive drum for holding an electrostatic latent image on its surface, the photosensitive drum being driven to rotate by a motor, (ii) charging means for charging the surface of the photosensitive drum so that the surface has a predetermined polarity and a predetermined potential, (iii) exposing means for forming an electrostatic latent image by exposing the charged surface of the photosensitive drum, and (iv) developing means for developing the electrostatic latent image, and is arranged so that after stop of the motor due to occurrence of a trouble, during an inertial rotation time in which the photosensitive drum rotates due to an inertial force, the exposing means executes discharge exposure with respect to a charge remaining region on the surface of the photosensitive drum.

Image forming apparatus with discharging exposure after shutdown

A photosensitive element is produced with a minimum amount of a conductive synthetic resin material. A draft for injection molding is formed in the inner circumferential surface as a supporting body, and a driven member provided with a gear is fixed to the end of the supporting body with a smaller inner diameter, that is, the thicker end. A driven portion in which a plurality of projections and depressions are formed alternately to be adjacent to each other in the circumferential direction is arranged on an axial end of a cylindrical supporting body made of a conductive synthetic resin, including a photosensitive layer on the outer circumferential surface. By a joint member removably engaged with the driven portion, the supporting body is rotated around the axis. In one arrangement, only the end of the supporting body is solid. In another arrangement, the supporting body is solid in the almost entire length in the axial direction.

Photosensitive element for electrophotography

Growing community of inventors

Yamatokoriyama, Japan

Keizo Kitamura