Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system
Patent
1995-01-20
1995-09-26
Young, W. R.
Dynamic information storage or retrieval
With servo positioning of transducer assembly over track...
Optical servo system
369 4424, 369112, G11B 7095
Patent
active
054539617
ABSTRACT:
An optical device for detecting focus error, tracking error and recorded data in an optical head system has a grating plate having a plurality of gratings and waveguides. The gratings are fabricated by holographic exposure of a resist layer spin-coated onto a glass substrate. The gratings include a processing grating to efficiently input couple light into the waveguide and to effect a desired change in the input coupling efficiency with defocus of a beam of light at an optical disk. The optimum pattern of the processing grating is based on the location and intensity variation of diffraction orders in the beam returning from the optical disk and appodization of the beam. Unfocused beams and large active areas of the detectors relax the tolerance for detector placement so that placement is not critical. The four focus and tracking detectors and data detector needed for complete signal processing are compactly formed on single chip.
REFERENCES:
patent: 4672187 (1987-06-01), Fujita et al.
patent: 4779259 (1988-10-01), Kono et al.
patent: 4794585 (1988-12-01), Lee
patent: 4833561 (1989-05-01), Sunagawa et al.
patent: 4868803 (1989-09-01), Sunagawa et al.
patent: 4876680 (1989-10-01), Misawa et al.
patent: 4885732 (1989-12-01), Sunagawa et al.
patent: 4937808 (1990-06-01), Shimada et al.
patent: 5050154 (1991-09-01), Shimozawa et al.
patent: 5070488 (1991-12-01), Fukushima et al.
patent: 5231620 (1993-07-01), Ohuchida
patent: 5233595 (1993-08-01), Kawakubo
Li, Application of Diffraction Grating Theory to Analysis and Fabrication of Waveguide Gratings, Ph.D. Disertation, University of Arizona, vol. 49, No. 5, Nov. 1988.
Alling et al., Image Reversal of Positive Photoresist, SPIE Proceedings, vol. 539, Advances in Resist Technology, p. 194 (1985).
Eastman Kodak Company
Owens Raymond L.
Young W. R.
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