| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain spherical aberration correction value of each layer of a multi layered optical disk in a small amount of time. <P>SOLUTION: A driver 12 rotates a spindle motor 11, a CPU 22 controls an optical pickup 13 for sweeping up and down to detect the deepest layer of the multi layered optical disk 1, and the CPU 22 adjusts an expander of the layer and records the correction value into a non volatile memory 21. Next, the CPU 22 obtains the number of layers from disk information in a Lead-in-Data of the optical disk 1 to jump to the shallowest layer and adjust the expander of the layer, and records the correction value into the non volatile memory 21. The CPU 22 obtains the correction values of other layers by calculating based on the correction values of the two layers. <P>COPYRIGHT: (C)2008,JPO&INPIT |
