Patent ID: 7558503

Claim:
An image forming apparatus, comprising: an image carrier; a charger apparatus which charges an effective charging area of said image carrier using a proximity charger roller which is conductive and is disposed in proximity to a surface of said image carrier; an exposure apparatus which forms a latent image in said effective charging area; a developer apparatus which develops said latent image with a developer; and a driver which drives said image carrier into rotations, wherein said charger apparatus comprises: a pair of abutting portions which abut on said image carrier at both edges which are located on outer side of said effective charging area, thereby maintaining a proximity distance from said proximity charger roller to said image carrier constant; and a cleaning roller which has an elongated shape longer than a spacing between said pair of abutting portions, has a pair of edge portions and a central portion in between, and is pressed against said proximity charger roller on an opposite side of said image carrier relative to said proximity charger roller in a condition that both of said pair of edge portions are located respectively facing said pair of abutting portions, thereby making said proximity charger roller abut on said image carrier with said pair of abutting portions between and cleaning a surface area of said proximity charger roller which is between said pair of abutting portions with said central portion, a gear train is provided which links a rotation shaft of said image carrier to a rotation shaft of said cleaning roller without linking to a rotation shaft of said proximity charger roller so that said gear train transmits a rotational drive force of said driver to said cleaning roller, which accordingly rotates in the same direction as said image carrier, a center of an axis of the rotation shaft of said image carrier, a center of an axis of the rotation shaft of said proximity charger roller, and a center of an axis of the rotation shaft of said cleaning roller are located in-line, said pair of abutting portions are disposed on an outer circumferential surface of said proximity charger roller so as to project therefrom, and said proximity charger roller rotates driven following rotation of said image carrier due to frictional force via said pair of abutting portions, the frictional force being enhanced by a pressing force from said cleaning roller.