| 摘要 |
PURPOSE:To stabilize a recording and reproducing operation in a difracted light tracking type optical disc device by detecting and storing the offset of a tracking signal and compensating the offset on the basis of the stored value. CONSTITUTION:A radius position on an optical head disc is positioned on the basis of an external scale such as moirescale. An RAM12 is accessed by using said positioning obtained through a bus line 60 as an address through a latch circuit 61 to store the offset value of tracking signal outputted from the optical head on the corresponding position through an A/D converter 12 in the RAM62. When the stored contents are read out, an offset value obtained through a D/A converter 14 is determined to be inserted in accordance with the optical head position and the offset value is compensated, the tracking offset value is cancelled practically, so that the recording and reproducing operation is stabilized. |
