| 摘要 |
PURPOSE: A method for recording/playing an optical disk is provided to compensate the optical aberration owing to the difference in thickness of disks accurately. CONSTITUTION: An optical pickup accesses test areas in a read-in area(12) for each layer by driving a laser diode(20) with a test order of a control unit(38). A playback signal processing unit(36) detects a RF signal of each layer by processing an optical detecting signal from an optical detector(24). The control unit(38) decides the layer detected the RF signal having the best signal quality by comparing RF signals of each layer and detects a thickness difference between the layer and the data area. And, the control unit(38) feeds a control voltage into a liquid panel(26) to compensate a spherical aberration amount according to the difference of thickness. Therefore, the liquid panel(26) changes a refractive index of projected lights according to the control voltage and compensates the spherical aberration amount. |
