Liquid crystal driving apparatus, laser head and CD disc device


Application Number: 00109297
Application Date: 2000.06.22
Publication Number: 1278095
Publication Date: 2000.12.27
Priority Information: 1999/6/22 JP 175319/1999; 1999/9/29 JP 275667/1999
International: G02F1/133;G02F1/1343;G11B7/095;G11B7/135
Applicant(s) Name: Matsushita Electric Industrial Co., Ltd.
Address:
Inventor(s) Name: Anta Katsuhiko;Nigita Hidehiko;Ogata Taisuke
Patent Agency Code: 11021
Patent Agent: wang huimin
Abstract Tilt which is inclination of a normal of optical disk relative to optical axis of optical head is corrected with a liquid crystal element. In a driver for the liquid crystal element, a periodic waveform generator generates periodic waveform and an inverting element inverts the periodic waveform. The periodic waveform and the inverted waveform are connected to two ends of a potential divider which provides partial voltages. The periodic waveform is connected to a common electrode of the liquid crystal element, and the partial voltages of the potential divider are connected to electrodes opposing the common electrode. A structure of a driver circuit for each direction is simple. Tilt in a plurality of directions can be performed independently of each other. Spherical aberration is also corrected. When the liquid crystal element is mounted to a fixed component, deterioration due to jitters is reduced.