| 摘要 |
PURPOSE:To attain the angular displacement correction of an optical recording medium with high accuracy by utilizing a read data from a photoelectric detection sensor so as to detect the displacement of a reference line of an optical recording medium. CONSTITUTION:A reference line detection circuit 20 detects a reference line 4 from an output signal of a CCD sensor 10. Then a reference line position detecting circuit 30 detects the position of the reference line within the visual field of the sensor 10 detected by the reference line detection circuit 20. An angular displacement detection circuit 40 stores the position of the reference line detected at least at two points in the lengthwise direction of the reference line, obtains the displacement from the difference of the both and calculates the angular displacement from said displacement and the distance between two points. The calculated angular displacement is used as a control signal to correct the relative angular displacement between the optical recording medium 2 and the sensor 10. Thus, the angular displacement of the optical recording medium is corrected with high accuracy.
|
