Servo optical pick-up device

Abstract

Abstract PURPOSE:To correctly apply tilt control to an optical pick-up by using a photodetector to obtain a focus error signal to obtain the angle information of a disk surface and the light projected on it. CONSTITUTION:An optical pick-up 31 is freely movably provided in the radius direction of a disk 30. A pick-up 31 has a laser light detecting device 311 and a laser beam is projected through a radial mirror 312 and an objective lens 313 to the disk 30. The laser beam reflected from the disk 30 is made incident on a photodetector 314 having a light receiving element divided into four. The output of the photodetector 314 is supplied to a differential amplifier 314, a focus error signal is obtained, and the angle information of the laser beam supplied to a differential amplifier 316 and projected on the disk surface is obtained. By using the output of the amplifier 316, a voice coil 35 is driven and the inclination of the mirror 312 is controlled. Thus, the correct tilt control can be executed.

Inventors

• 👤 Masamitsu Mishina

Bibliographic Details