| 摘要 |
PURPOSE:To improve accuracy in measuring optical disk plane deflection based on a current value of a focus direction driving coil by driving an optical pickup by a certain width for a certain time on the disk side in the focus direction or the opposite side before measuring when the plane deflection quantitiy of the optical disk is measured. CONSTITUTION:An optical disk 4 is controlled by a focus by rotating a disk motor, and whether or not the optical disk 4 is aligned with the pickup side is decided by the outputted light of an equivalent filter 5. When the optical disk 4 is aligned with the counterpickup side, the focus control is stopped, and an optical pickup 1 is driven by a certain width for a certain time on the disk side in the focus direction. After that, the optical disk is controlled by the focus again, and the outputted value of the equivalent filter 5 is detected. When the optical disk 4 is aligned with the pickup side, the focus control is stopped, and the optical pickup 1 is driven by a certain width for a certain time on the counterdisk side in the focus direction. After that, the optical disk 4 is controlled by the focus again, and the disk plane quantity is measured by detecting the outputted value of the equivalent filter 5. |
