| 摘要 |
PURPOSE:To reproduce information, which are recorded with high density, without fail by executing the tracking control of an optical head from a servo area through the servo signal of a sample format, forming one spot to the plural bits of a data area and simultaneously reading the plural information. CONSTITUTION:The tracking control is executed to the optical head based on the servo signal of the sample format, which is obtained from a servo area ARS of an optical disk 12, and one optical spot SP is formed to plural bits PA and PB which are formed in a data area ARD. A returning optical beam LA1 of an optical beam is guided to a light receiving part 14 and the plural bits of information are simultaneously read from the data area ARD based on a sum signal S and a difference signal S to plural output signals SA and BB which are outputted from the light receiving part 14. Thus, even when the information is recorded with the high density in the data area ARD, the plural bits of information can be read without fail. |
