| 摘要 |
<p>An optical head comprises a photodetector (8) having divided photosensitive areas to detect light (13) reflected from an optical disk (7), means (10, 11, 12) for obtaining tracking error signal by operating signals from the photosensitive areas. The photodetector (8) has a first division line (9a) parallel to an information track on the optical disk and second and third division lines (9b, 9c) perpendicular to the first division line (9a) and symmetrical to the optical axis. Further, a light-shielding area (8i) for shielding a part of the reflected light between the division lines (9b and 9c). The signals are operated to reduce offset of the tracking error signal due to shift of object lens and tilt of the optical disk. Then, the optical head has small offset of tracking error signal with a simple structure as prior art optical head of push-pull technique.</p> |
