Image formation method for forming electrostatic latent image on photosensitive belt with laser beam and image formation apparatus of the same

摘要

An image formation apparatus of the present invention forms an electrostatic latent image on a moving photosensitive belt by a laser beam produced by a laser device. A belt edge detector 1 detects an edge portion (belt edge) of a photosensitive belt 100 in a main scanning direction. A virtual edge detection circuit 2 generates a virtual edge detection signal 2A which changes a generation timing in accordance with a change of a detection timing of the belt edge detected by the belt edge detector 1. The generation timing of the virtual edge detection signal 2A does not almost follow the detection timing of the belt edge which changes by flaws and non-linearity of the belt edge, and changes in accordance with a slow change of the detection timing. A synchronizing signal generation circuit 3 and a driving circuit 4 drives the laser device so as to start a writing of an image data by the laser beam in synchronization with the virtual edge detection signal.