Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Patent
1993-07-08
1995-05-02
Epps, Georgia Y.
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
369 4412, 369 4423, 369 4441, 369103, 369109, 369112, G11B 7135
Patent
active
054126312
ABSTRACT:
An optical head apparatus consists of a light beam source, a blazed hologram partitioned into diffraction regions for mainly changing the light beam radiated from the light beam source to zero-order diffraction light and secondarily diffracting the light beam to produce beams of unnecessary light such as N-order diffraction light (N.noteq.0), an information medium for storing information, an objective lens for converging the zero-order diffraction light and the unnecessary light at the information medium, and a six-division photo detector having six detecting sections for detecting intensity of first-order diffraction light produced by diffracting the zero-order diffraction light in the blazed hologram. A hologram pattern of the blazed hologram is formed to function as a lens for the unnecessary light. A focus servo signal is produced according to mutual relation among intensities of the first-order diffraction light detected in the six detecting sections to focus the objective lens on the information medium For the zero-order diffraction light. Therefore, the objective lens is not focused on the information medium for the unnecessary light. Also, the beams of the unnecessary light diffracted in each of the diffraction regions of the blazed hologram are greatly widened because numerical apertures of the diffraction regions are small.
REFERENCES:
patent: 4731772 (1988-03-01), Lee
patent: 4918300 (1990-04-01), Tsuji et al.
patent: 4929823 (1990-05-01), Kato et al.
patent: 4945529 (1990-07-01), Ono et al.
patent: 5049732 (1991-09-01), Nagahama et al.
patent: 5128914 (1992-07-01), Kurata et al.
patent: 5231620 (1993-07-01), Ohuchida
Kato Makoto
Komma Yoshiaki
Nishino Seiji
Edun Muhammad N.
Epps Georgia Y.
Matsushita Electric - Industrial Co., Ltd.
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