| 摘要 |
PROBLEM TO BE SOLVED: To materialize a drive circuit and a drive method of a laser light source capable of destructive prevention function of the laser diode by an operative temperature rise with high precision and easy structure. SOLUTION: The drive circuit 1 comprises a constant current generator 2 for supplying current to a photodiode 12B so that bias may be set to the forward direction of the photodiode 12B, a detection means 3 for detecting the forward direction voltage of the photodiode 12B, a judging means 4 for judging whether the forward direction voltage detected by the detection is smaller than a predetermined reference voltage, and a control means 5 for controlling the supply of current to a laser diode 12A by a current source 11. When the judging means 4 judges the forward direction voltage being smaller than the reference voltage predetermined, the control means 5 controls the current source 11 to make it stop current supply to the laser diode 12A. COPYRIGHT: (C)2007,JPO&INPIT
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