Patent ID: 6249304
Filing Date: 2001-06-19
Classification: G03G,H04N

Abstract:
An image forming apparatus which comprises:a photosensitive member comprising a photosensitive layer of Tp thickness on a surface thereof;a charging unit configured to uniformly charge the surface of the photosensitive member;an image exposure unit configured to form an electrostatic latent image by exposing the photosensitive member with a light beam;a gray-level image device configured to transmit a drive signal to the image exposure unit, and to produce a gray-level image in accordance with a gray-level image signal based on image data including gray-level information;a developing unit configured to develop an electrostatic latent image formed on the photosensitive member; anda transfer unit configured to transfer a developed image from the photosensitive member to a recording medium;wherein a relationship between the thickness Tp of the photosensitive layer on the photosensitive member and an exposure diameter Db of the light beam is defined as2Tp<Db,where the exposure diameter Db is a minimum diameter at 1/e.sup.2 with respect to a peak value in an exposure distribution determined by integrating an energy distribution of the light beam on the photosensitive member with an exposure time, andthe image exposure unit is configured to set a maximum exposure within the exposure diameter Db of the light beam at a value such that a differential sensitivity of the photosensitive layer of the photosensitive member is sufficiently small in order that the gray-level image will be produced as a result of damping characteristics of the photosensitive member.