Patent ID: RE40109

Claim:
A multi-beam optical scanner comprising: a light source for a multi-beam; a coupling lens for coupling a plurality of light fluxes from said light source for a multi-beam to an image-forming optical system; a first image-formation system for focusing a plurality of light fluxes coupled by said coupling lens in a direction corresponding to auxiliary scanning and forming them to images as a plurality of line images each long in a direction corresponding to main scanning; an optical deflector having a deflecting reflection surface adjacent to positions where images as said plurality of line images are formed for deflecting said plurality of light fluxes; a second image-formation system for separating the plurality of light fluxes deflected by said optical deflector from each other in a direction of auxiliary scanning on a scanned surface and converging the plurality of light fluxes as a plurality of light spots for optically scanning said scanned surface in accordance with deflection of the light fluxes; wherein a lateral magnification β in a direction corresponding to the auxiliary scanning in a composite system of the optical system between said light source for a multi-beam and said scanned surface is as follows: 2<β and the plurality of light spots on the scanned surface optically scan scanning lines adjacent to each other.