| 摘要 |
PROBLEM TO BE SOLVED: To allow a multi-beam light quantity controller, which uses multiple laser beams, to end APC operation for all the beams precisely in a short period with a simple circuit constitution. SOLUTION: This controller has a comparator AMP2 which converges a part of the light of a semiconductor laser array emitting beams on a photodetector 7, performs the voltage conversion AMP1 of the light quantity of the light beam obtained by the photodetector, and compares the result with one reference voltage. To determine and hold the comparison result on a time-division basis, selecting circuits SW1, SW2, etc., and integrating circuits R3C1, R6C2, etc., are provided corresponding to the respective beams of the semiconductor lasers. The respective beams are selected and emitted on a time-division basis without being adjacent to one another as much as possible and one selecting circuit operates in a section shorter than the light emission section of one beam within the light emission section. |
