Patent ID: 9130341
Filing Date: 2015-09-08
Classification: H01S

Abstract:
1. A semiconductor laser drive apparatus comprising: a semiconductor laser element supplied with a drive current, the drive current being controlled according to a light-emission control signal indicating on or off; a drive circuit that generates a drive current corresponding to an input current and supplies the drive current to the semiconductor laser element; a current setting circuit that stores a first set value for a light-emission current obtained by subtracting a first bias current used when the semiconductor laser element emits light, from a drive current used when the semiconductor laser element emits light of a desired amount of light emission, a second set value for the first bias current, and a third set value for a second bias current used when the semiconductor laser element does not emit light; a first current generator circuit that generates a first input current from the first set value; a second current generator circuit that generates a second input current from the second set value and generates a third input current from the third set value; and a switching circuit that supplies a sum of the first and second input currents to the drive circuit when the light-emission control signal is on, and supplies the third input current to the drive circuit when the light-emission control signal is off, wherein the current setting circuit: