| 摘要 |
PURPOSE:To set the output power of a semiconductor laser prior to a recording or erasing action and to output a stable recording power or erasing power free of the influence of environmental temperature by generating a second control signal by comparing an output from a beam detection circuit and a reference value stored in a memory means. CONSTITUTION:A control means 20 compares the reference value stored in its own memory means with an output signal from an amplifier 14, and controls a reference value generation circuit 13, and a first and a second control signal generation circuits 16, 18 based on the result of said comparison. And prior to a recording and/or erasing action by an optical information recording device, an output from the semiconductor laser 21 is set in a target value for the recording and/or erasing of information. Thus the elimination of offset of the circuit and the adjustment of the output power of the semiconductor laser 21 are achieved preceding to a recording/erasing action, therefore, the difference between a semiconductor laser output in action and that at the time of adjusting can be eliminated. |
