Patent ID: 7457552
Filing Date: 2008-11-25
Classification: G03G,H04N

Abstract:
1. An image forming apparatus, comprising: a rotatable image bearing member; a charging device configured to charge the image bearing member evenly in a longitudinal direction; an exposure device configured to expose the image bearing member charged by the charging device with an optical beam and form a latent image; an electric potential detecting device configured to detect surface electric potentials of the image bearing member at a plurality of places in the longitudinal direction; and a control device configured to change an exposure intensity of the optical beam for each of a plurality of areas into which the image bearing member charged with a first bias by the charging device and the image bearing member charged with a second bias that is different from the first bias by the charging device are divided in the longitudinal direction, and thereby determine the bias to the charging device necessary for obtaining a predetermined electric potential of a dark section and the exposure intensity of the optical beam to be irradiated from the exposure device necessary for obtaining a predetermined electric potential of a bright section, on the basis of the surface electric potentials of the image bearing member that are detected by the electric potential detecting device in each of the areas.