Laser beam intensity control device and laser light intensity control method

摘要

PROBLEM TO BE SOLVED: To provide a laser light intensity control device that has a short time from reception of reflected light from an object OB to be measured to control over intensity of emitted laser light, eliminates the need for a photodetector to receives reflected light from a light receiver receiving the reflected light, and can precisely perform intensity control over the emitted laser light even in the presence of stray light.SOLUTION: A laser light intensity control device 30 repeats the processes of: inputting received light intensity data that a sensor signal extraction circuit 40 outputs at intervals of fine time and a signal that a back monitor 18 that a laser light source 16 comprises outputs; and calculating and outputting to a laser drive circuit 14 intensity of a drive signal for letting a width of a received light intensity curve, generated from the received light intensity data, at a preset level of intensity reaches a preset width.SELECTED DRAWING: Figure 1