Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Patent
1997-08-01
1999-01-05
Epps, Georgia
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
369 4441, 369 4437, G11B 700
Patent
active
058569596
ABSTRACT:
A method and an optical pickup device for generating a focus error signal are disclosed. The device includes an irradiation optics for irradiating laser beams onto an information recording surface of an optical disc, a first and a second photodetector for receiving reflected light, and photodetection optics having an astigmatism generating element for applying astigmatism to light reflected from the information recording surface and for introducing the reflected light to the first and the second photodetectors. The device also includes first and second photodetecting circuits which generate a first and a second preliminary focus error signal. The photodetecting circuits include a first and a second diagonal adder connected to the first and the second photodetector, and a diagonal differential device connected to the first and the second diagonal adders for generating an output difference between outputs of the first and the second diagonal adders as the first and the second preliminary focus error signals. The device further includes a device for generating a focus error signal calculated from the first and the second preliminary focus error signals.
REFERENCES:
patent: 4829506 (1989-05-01), Bressers et al.
patent: 4888752 (1989-12-01), Arai
patent: 5113386 (1992-05-01), Whitehead et al.
patent: 5173890 (1992-12-01), Miyake et al.
patent: 5241523 (1993-08-01), Kessler
patent: 5282192 (1994-01-01), Yamada et al.
patent: 5391865 (1995-02-01), Kurata et al.
patent: 5412631 (1995-05-01), Komma et al.
patent: 5491675 (1996-02-01), Kay
patent: 5493425 (1996-02-01), Yang
patent: 5557601 (1996-09-01), Nishikawa
patent: 5629916 (1997-05-01), Komiya
patent: 5696749 (1997-12-01), Brazas, Jr. et al.
patent: 5761162 (1998-06-01), Gerber et al.
Epps Georgia
Mack Ricky
Pioneer Electronic Corporation
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