Patent ID: 7970029

Claim:
A method for driving at least one semiconductor laser, comprising: detecting the output of the at least one semiconductor laser with at least one photodetector; comparing the output of the at least one photodetector against a set value corresponding to a target light output of the at least one semiconductor laser; and controlling the drive current of the at least one semiconductor laser based on the comparison results, wherein: a correction pattern, which is defined according to the amount of time which has passed since initiating driving thereof, that enables obtainment of a substantially uniform light output is generated in advance; and the set value and/or the output of the at least one photodetector is varied according to a single correction pattern for a predetermined period of time from initiation of drive of the at least one semiconductor laser, wherein: in the case that laser beams emitted from the plurality of semiconductor lasers are combined, varying the set value and/or the output of the at least one photodetector according to the correction pattern is performed with time lags among the plurality of semiconductor lasers.