Patent ID: 6831763
Filing Date: 2004-12-14
Classification: B41J,G02B

Abstract:
A scanning optical system for dynamically deflecting a plurality of laser beams by a deflecting system for a plurality of scan targets which are provided corresponding to the laser beams and parallelly arranged at preset intervals, converging the dynamically deflected laser beams by an imaging optical system into spot beams on said corresponding scan targets respectively, and thereby scanning the spot beams in a main scanning direction on said corresponding scan targets respectively,wherein said deflecting system includes at least one reflecting surface which simultaneously deflects the laser beams that are incident on the at least one reflecting surface at incident angles differing in an auxiliary scanning direction perpendicular to the main scanning direction, and wherein said imaging optical system including: a front lens group having positive refractive power for converging all the laser beams from said deflecting system principally in the main scanning direction while deflecting at least a pair of laser beams selected from the laser beams obliquely incident on said at least one reflecting surface so as to let the selected laser beams deviate from an optical surface reference axis of said front lens group; and a plurality of rear lens groups each of which has positive refractive power for converging each of the laser beams that passed through said front lens group principally in the auxiliary scanning direction.