| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the change of the position of an optical member adjusted before power-on when power is turned ON. <P>SOLUTION: An expander lens 14 disposed in an optical pickup device 10 for correcting a spherical aberration or a chromatic aberration is subjected to displacement control in an optical axis direction by a motor 23. The position of the expander lens 14 is detected by a position sensor 24. An operation amplifier 31 receives a set analog voltage signal indicating an optimal position from a microcomputer 35 and a D/A converter 34 and a detected analog voltage signal from the position sensor 24 to drive and control the motor 23 by a differential operation, thereby maintaining the optimal position of the expander lens 14. After a power switch 42 is turned ON, detected analog voltage signals are supplied to both inputs of the operation amplifier 31 to stop and control the motor 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
