| 摘要 |
PURPOSE:To reduce the error from the final target value of light emission power just after power-on of a disk drive device or just after the start of power control of a laser diode. CONSTITUTION:At the time of power-on, the power target value of a laser diode 1 is set to an initial target value P2 smaller than a final target value P1; and after a prescribed time, a selector 9 is switched by the control of a control signal S of a timer or a CPU, and the final target value P1 is set to control the power of the laser diode 1. If plural initial target values are provided and the smallest target value is successively switched to larger target values, the error from the final target value of the initial light emission power of the laser diode is reduced furthermore. |
