| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve high speed laser power control using an error amplifier having time constant. <P>SOLUTION: In an APC circuit 1, irradiation power of a laser beam of a laser diode 101 is decided by a DAC value set to DAC of an error amplifier 105b having time constant, but when the irradiation power of the laser beam emitted by the laser diode 101 is changed to target irradiation power, and when the DAC value of the error amplifier 105b is changed, a DA converter update control part 107 changes DAC values of Pw-DAC112, Pe-DAC113, and Pb-DAC114 so that a current to obtain the target irradiation power may flow in the laser diode 101. Thereby, laser power is controlled at high speed. <P>COPYRIGHT: (C)2008,JPO&INPIT |
