| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize an optical pickup which enables both an average light volume and a peak light volume to be controlled with high accuracy. <P>SOLUTION: A semiconductor laser diode LD2 is driven by a high-frequency drive current HI2, and the optical pickup 23 is equipped with a laser drive circuit 40 which drives the laser diode LD2 to emit a high-frequency light beam L1. An APC circuit 40A detects the average light volume of the high-frequency light beam L1 and feedback-controls the drive current I2 on the basis of the above average light volume, and a superimposition amplitude control circuit 40B detects the peak light volume of the high-frequency light beam L1 and feedback-controls the amplitude A of the high-frequency drive current HI2 on the basis of the above peak light volume independently of control by the APC circuit 40A. The average light volume and peak light volume of the high-frequency light beam L1 emitted from the semiconductor laser diode LD2 can be separately controlled, so that both the average light volume and peak light volume of the light beam L1 can be surely controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
