Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Patent
1994-02-16
1996-05-07
Young, W. R.
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
369 4432, 369 54, G11B 7095
Patent
active
055153488
ABSTRACT:
An optical pickup is adapted for recording and/or reproducing signals by radiating a light beam from a light source on an optical recording medium via an object lens. The optical pickup includes a light receiving device for receiving a return light from the optical recording medium, and a focusing error detecting unit for detecting an amount of deviation of the focal point along the optical axis. The measurement of a focusing error is based on signals from the light receiving device. The optical pickup further includes an electrostriction device arranged on a path of light outgoing from the light source to the optical recording medium and having a central section and a peripheral section exhibiting a phase difference from each other depending on an applied voltage. Focusing errors may be detected with high accuracy with the optical pickup. A focusing servo device compensates for the focusing error detected by controlling the focal point along the optical axis using a focusing servo device. Depending on error detection signals from the focusing error detection unit, a rough servo is carried out by an the object lens driving unit to the vicinity of the depth of focus, and a fine servo is carried out by the electrostriction device within the range of the depth of focus.
REFERENCES:
patent: 4661943 (1987-04-01), Ikeda
patent: 4737946 (1988-04-01), Yamashita et al.
patent: 4816665 (1989-03-01), Hsu
patent: 4861975 (1989-08-01), Kino et al.
patent: 4937808 (1990-06-01), Shimada et al.
patent: 5027336 (1991-06-01), Sugiura
Patent Abstracts of Japan, vol. 10, No. 41 (P-429), 18 Feb. 1986 & JP 60-187920 (Matsushita Denki Sangyo KK).
Patent Abstracts of Japan, vol. 12, No. 345 (P-759), 16 Sep. 1988 & JP-A-63 103 445 (Fujitsu General Ltd).
Patent Abstracts of Japan, vol. 14, No. 158 (P-1027), 27 Mar. 1990 & JP-A-20 14 433 (Toshiba Corp.).
Patent Abstracts of Japan, vol. 9, No. 276 (P-402), 2 Nov. 1985 & JP-A-60 121 546 Sony (KK).
Patent Abstracts of Japan, Group No. P714, vol. 12, No. 199, Abs Pub Date Jun. 9, 1988 (63-2125).
The Photonics Dictionary, 1991 pp. D-102, D-103.
Sony Corporation
Young W. R.
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