| 摘要 |
PURPOSE: To additionally reduce access time without mechanically moving by deflecting a laser beam through the use of an acoustic optical element and scanning the laser beam to a desired position on an optical disk. CONSTITUTION: The laser beam incident to the acousto-optical element 41 from a light source part 30 and polarized in a desired direction by the element 41 is incident on a beam scanning part 5 and is formed to be a fine beam spot by the scanning objective lens of the scanning part 50 to be scanned on the optical disk 70. Next, the laser beam reflected on the disk 70 is incident on the lens 52, incident on the bottom face of a light divider 51, reflected from there, incident on a focusing lens 53 and incident on a light detection part 60. The beam is incident on the detection part 60, a signal is processed by a signal processing circuit, access positional information is fedback to an acousto-optical element control part 42, and the control part 42 controls the ultrasonic frequency of the element 41 so as to scan the beam at a desired position on the disk 70. |
