Patent ID: 7425975
Filing Date: 2008-09-16
Classification: B41J

Abstract:
1. A multi-beam image forming apparatus comprising: a first semiconductor laser array having n laser elements, wherein n is an integer not smaller than 2; a second semiconductor laser array having n laser elements; a multi-beam generation unit that generates 2n laser beams by synthesizing laser beams generated by the first and second semiconductor laser arrays; a scanning unit that scans with the 2n laser beams generated by the multi-beam generation unit; a beam detection unit that generates synchronous detection signals to obtain synchronous scanning of the respective laser beams; and a control unit; wherein the beam detection unit includes first and second beam detection units disposed substantially at a same position in a main scanning direction and adjacently disposed in a sub-scanning direction orthogonal to the main scanning direction; wherein the n laser beams of the first semiconductor laser array are detected by the first beam detection unit while the n laser beams of the second semiconductor laser array are detected by the second beam detection unit; and wherein the control unit controls image formation start positions of the 2n laser beams on the basis of the synchronous detection signals output from the first and the second beam detection units.