| 摘要 |
PROBLEM TO BE SOLVED: To provide the offset correcting method of a tracking error signal, in which the offset of a tracking error signal (push-pull signal) which is generated due to the shift of an objective lens or the like is corrected over a wide range. SOLUTION: When the push-pull signal obtained from outputs of the photodetecting sensor 20 having bisected segments C, D of an optical pickup by irradiating the groove part of a disk with a laser beam is used as a tracking error signal TE, the offset of the tracking error signal is corrected by calculating a middle-point level from the + peak level and the - peak level being in roughly the same amplitude states of a land prepit signal which are generated due to left and right prepits 24 on a land part which is formed alternately with the groove part of an optical disk 2 and by operating the middle-point level and the push-pull signal so that the reference level of the push-pull signal is overlapped on the middle-point level. Thus, the offset of the tracking error signal (push-pull signal) which is generated due to the shift of the objective lens or the like is corrected over the wide range.
|
