| 摘要 |
PURPOSE:To simplify the structure of a rotation adjusting part by permitting a reflection mirror to be supported and rotated by a knife edge-shaped receiving part and permitting positioning by energizing in the returning direction according to rotational displacement from a neutral position. CONSTITUTION:A laser beam 4 projecting from a laser beam oscillator is reflected on a reflection mirror 21 which is positioned by a reference, and the reflected light 4a advances along the optical path indicated with a solid line and then it is reflected on a reflection mirror 12 of a movable optical system 7, then rising as a reflection light 4b as shown with a solid line so as to be irradiated onto a track 6 of a disk 2. When a coil 27 is applied with a current, the reflection mirror 21 slightly rotates as shown with a dashed line around the optical path of the reflected light 4a shown with a solid line, and the reflected light advances as indicated with one-dashed chain line so as to irradiate onto the track which lies toward the central part from the reference position of the disk 2, thus, an irradiated point is finely adjusted. |
