CONTROL METHOD AND CONTROL DEVICE FOR LASER POWER OF SEMICONDUCTOR LASER AND RECORDING/REPRODUCING METHOD AND RECORDING/REPRODUCING DEVICE FOR MAGNETOOPTIC RECORDING MEDIUM AND RECORDING/REPRODUCING METHOD AND RECORDING/REPRODUCING DEVICE FOR OPTICAL RECORDING MEDIUM

摘要

A method of controlling the laser power of semiconductor laser, which controls the laser power of semiconductor laser by applying a power source voltage to between the collector and emitter of an output transistor and to the series circuit of semiconductor laser, wherein power consumption at an output transistor can be reduced. A variable power source voltage (Vcc), which is applied to an output transistor (Qb) and the series circuit of semiconductor laser (SL), is controlled so that the difference between the variable power source voltage (Vcc) and the peak hold voltage of the operating voltage of the semiconductor laser (SL) is almost constant.