Patent ID: 6281922
Filing Date: 2001-08-28
Classification: B41J,G02B,H04N

Abstract:
An image forming apparatus comprising:a plurality of light sources each for modulating and emitting a light beam based on image data at an operation speed responsive to a predetermined clock;an optical scanner for deflecting the light beams emitted from said plurality of light sources by a single deflector, dividing one scanning line on an image carrier rotating in a predetermined direction by the deflected light beams, and scanning the light beams over the line in a main scanning direction;a detector for detecting a position displacement amount in a boundary portion of areas over which the light beams are scanned; anda controller for controlling light beam emission start timings from said light sources or clock frequencies corresponding to said light sources so as to eliminate a displacement amount in the main scanning direction if the position displacement amount detected by said detector contains the displacement amount in the main scanning direction, and for controlling said light sources so as to modulate and emit the light beams based on image data of a scanning line shifted as many lines as the number of lines responsive to a displacement amount in a rotation direction of the image carrier if the position displacement amount contains the displacement amount along the rotation direction.