| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser driving device and a driving method which prevent excessive laser output. SOLUTION: V<SB>pd</SB>andΔV<SB>pd</SB>are detected by a photodiode which detects laser light of a solid-state laser. TheΔV<SB>pd</SB>is a fine voltage which is output when the photodiode receives light such as leak of an excitation semiconductor laser, and the V<SB>pd</SB>is a voltage output when the photodiode receives laser light. Thresholds V1, V2 are provided toΔV<SB>pd</SB>and V<SB>pd</SB>each. In rising of laser driving,ΔV<SB>pd</SB>and the threshold value V1 are compared and presence or absence of the voltageΔV<SB>pd</SB>is detected. When there is noΔV<SB>pd</SB>, it is judged that a circuit part is abnormal. Consequently, masking for avoiding influence due to delay of light emission in rising becomes unnecessary. COPYRIGHT: (C)2005,JPO&NCIPI |
