| 摘要 |
PURPOSE:To accurately detect the slanting angle of a disk, by providing a means which emits a light irrespective of a pickup beam upon the surface of the disk and another means which receives the reflecting light of the light from the disk surface and detects the change in the opposite direction. CONSTITUTION:A light emitting element 1 is arranged so that the optical axis of its emitting light can always maintain a fixed angle with the optical axis of a pickup beam 2 for reading and can be positioned adjacently to the irradiating location of the emitting light on a disk 3. When the light emitting element 1 and a photoreceptor 4 are moved while maintaining the above-mentioned relation between them correspondingly to the slide resulting from the tracking operation of a pickup 5, the relative slanting angle of the disk 3 which always is a recording medium in a reproducing track to the optical axis of the pickup beam 2 for reading can be detected though the change in the output of the photoreceptor element 4. Therefore, the slanting angle of the disk to the optical axis of the pickup beam can be detected accurately. |
