US4945525A
Expired / Lapsed
US
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Optical information processing apparatus
Assignee: Sharp Corp
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Filing: 1988-09-02
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Granted: 1990-07-31
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Expires: 2008-09-02
Abstract
Abstract An optical information processing apparatus including a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.
Inventors
- 👤 Osamu Yamamoto
- 👤 Toshihiko Yoshida
- 👤 Saburo Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:40
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1384; G11B7/123; G11B7/124
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
70 words
An optical information processing apparatus comprising: a substrate; means for projecting a plurality of laser light sports onto a recording medium; optical waveguide means formed on said substrate for receiving and for dividing laser light spots reflected from said recording medium into two sets of reflected light; photo-detector means for producing a tracking error signal from a comparison of the light intensity of each of said sets of reflected light.
Claim 2
Dependent Claim
70 words
An optical information processing apparatus comprising: a substrate; means for projecting a plurality of laser light sports onto a recording medium; optical waveguide means formed on said substrate for receiving and for dividing laser light spots reflected from said recording medium into two sets of reflected light; photo-detector means for producing a tracking error signal from a comparison of the light intensity of each of said sets of reflected light.
Claim 3
Dependent Claim
53 words
An optical information processing apparatus as recited in claim 1, wherein said optical waveguide means further comprises two optical waveguides disposed in a parallel relationship to each other, with the reflected laser spots being introduced respectively into said two optical waveguides so as to be divided into said two sets of reflected light.
Claim 4
Dependent Claim
24 words
An optical information processing apparatus as recited in claim 1, wherein said photo-detector means is formed on the substrate with said optical waveguide means.
Claim 5
Dependent Claim
25 words
An optical information processing apparatus as recited in claim 1, wherein said photo-detector means is positioned outside the substrate formed with said optical waveguide means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |