OPTICAL DISK UNIT AND PHASE SHIFT DETECTION METHOD APPLIED TO OPTICAL DISK UNIT

PROBLEM TO BE SOLVED: To detect a phase shift of a reproduction signal to improve the recording precision of an optical disk in an optical disk drive. SOLUTION: A first measuring pulse-row signal generation circuit 23 generates a first measuring pulse-row signal that rises in synchronization with the reproduction signal and falls in synchronization with a clock signal. A second measuring pulse-row signal generation circuit 24 generates a second measuring pulse-row signal that rises in synchronization with the clock signal and falls in synchronization with the reproduction signal. A jitter measuring unit 25 measures jitters in the first measuring pulse train signal and the second measuring pulse train signal. The phase shift in the reproduction signal is detected based on the measured jitters. COPYRIGHT: (C)2006,JPO&NCIPI