| 摘要 |
PROBLEM TO BE SOLVED: To attain the removal of DC offset of a tracking error signal in accordance with a lens sensor signal produced by various kinds of producing methods while keeping a tracking group gain to be constant. SOLUTION: In an operation amplifier circuit 6, when the lens sensor signal LS is produced by a non-reflective light method, the tracking error signal TE is passed as it is, and when the signal is produced by a reflective light method, the lens sensor signal LS from a gain circuit 5 is subtracted and the DC offset is removed, then it is supplied to a variable gain control circuit 9. In the variable gain control circuit 9, the tracking error signal TE is subjected to gain control by a total reflective light quantity signal PE and formed to the signal having the constant amplitude and supplied to the operation amplifier circuit 6. In the operation amplifier circuit 10, when the lens sensor signal is produced by a reflective light method, the tracking error signal TE is passed as it is, and when the signal LS is produced by a non-reflective light method, the lens sensor signal LS from the gain circuit 5 is subtracted and the DC offset is removed. COPYRIGHT: (C)2003,JPO
|
