| 摘要 |
PROBLEM TO BE SOLVED: To correctly obtain address information by reading the LLP signals in an optical disk unit. SOLUTION: This is a three-beam optical disk unit to record and reproduce signals on an optical disk by irradiating grooves with a main beam, by emitting the main beam from the front to the lands where the address information of the above grooves is recorded by using the first side beam, and emitting the main beam from the back to the second lands where the address information is recorded for the grooves neighboring the above grooves by using the second side beam. Further, it has an LLP detector 18 to obtain the LLP signals from the reflected light of the first side beam irradiating the first land preceding the main beam, an MPU20 to calculate the address information depending on the obtained LLP signals, and read the address information in advance. COPYRIGHT: (C)2004,JPO
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