The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 09, 2003
Filed:
Jun. 22, 2000
Katsuhiko Yasuda, Neyagawa, JP;
Hidenori Wada, Uji, JP;
Daisuke Ogata, Amagaski, JP;
Kanji Wakabayashi, Kyoto, JP;
Naoya Hotta, Sagamihara, JP;
Yoshihiro Ikawa, Higashiosaka, JP;
Yoshihiro Kanda, Osaka-fu, JP;
Masahiro Inata, Itami, JP;
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
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.