| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical head device without reducing precisions of focusing control and tracking control by the influence of a disk tilt of an optical disk. SOLUTION: In the optical head device 1, when a beam spot of laser beams reflected from the optical disk OD brought by an objective lens 19 is detected by a photodetector 37, a disk tilt (a tilt of the recording surface of the optical disk) is detected in off-tracking and a quantity that the objective lens is preliminarily displaced by a lens shift is detected in on-tracking based on an output corresponding to a deviation to either side of the inner peripheral side or the outer peripheral side in the radial direction of the optical disk. Thus, the reduction in precisions of focusing control and tracking control and the occurrence of mulfunctions are prevented. |
