Patent EP0306342A2 successfully refreshed from Google Patents.
EP0306342A2
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EP
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Optical information processing apparatus
Assignee: Sharp Corp
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Filing: 1988-09-02
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Granted: —
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Expires: 2008-09-02
Abstract
Abstract An optical information processing apparatus which includes a substrate (101) of a transparent material, first and second optical waveguides (102,103) formed on opposite faces of said transparent substrate (101), a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides (102, 103), 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 (102, 103).
Inventors
- 👤 Osamu Yamamoto
- 👤 Toshihiko Yoshida
- 👤 Saburo Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:06
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/135; G11B7/1384; G11B7/123; G11B7/124
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
An optical information processing apparatus which comprises a substrate (101) of a transparent material, first and second optical waveguides (102,103) formed on opposite faces of said transparent substrate (101), light introducing means for introducing reflected light from an information writing medium into said first and second optical waveguides (102, 103), and a detecting means for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into said first and second optical waveguides (102, 103).
Claim 2
Dependent Claim
80 words
An optical information processing apparatus which comprises a substrate (101) of a transparent material, first and second optical waveguides (102,103) formed on opposite faces of said transparent substrate (101), light introducing means for introducing reflected light from an information writing medium into said first and second optical waveguides (102, 103), and a detecting means for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into said first and second optical waveguides (102, 103).
Claim 3
Dependent Claim
140 words
An optical information processing apparatus which comprises a substrate (201), an optical waveguide (202) formed on said substrate (201), light introducing means for introducing light reflected from a recording medium into said optical waveguide (202) to form two collected light rays, a set of three-division photo-detector (206: 261, 262, 263) disposed before a focusing point of the reflected light introduced into said optical waveguide (202), and another set of three-division photo-detector (207: 271, 272, 273) disposed after a focusing point of the reflected light introduced into said optical waveguide, whereby in each of said two sets of three-division photo-detectors, differentiation between light receiving output at its central portion and a sum of light receiving outputs at its opposite sides is calculated so as to detect focusing error signal through comparison of the differentiation in said two sets of three-division photo-detectors.
Claim 4
Dependent Claim
140 words
An optical information processing apparatus which comprises a substrate (201), an optical waveguide (202) formed on said substrate (201), light introducing means for introducing light reflected from a recording medium into said optical waveguide (202) to form two collected light rays, a set of three-division photo-detector (206: 261, 262, 263) disposed before a focusing point of the reflected light introduced into said optical waveguide (202), and another set of three-division photo-detector (207: 271, 272, 273) disposed after a focusing point of the reflected light introduced into said optical waveguide, whereby in each of said two sets of three-division photo-detectors, differentiation between light receiving output at its central portion and a sum of light receiving outputs at its opposite sides is calculated so as to detect focusing error signal through comparison of the differentiation in said two sets of three-division photo-detectors.
Claim 5
Dependent Claim
106 words
An optical information processing apparatus which comprises a substrate (201), an optical waveguide (202) formed on said substrate (201), means for irradiating a plurality of laser light spots onto a recording medium so as to introduce the reflected light into said optical waveguide (202), and a set of photo-detectors for subjecting to photo-electric conversion, the reflected light introduced into said optical waveguide (202) for each reflected light ray corresponding to each spot of the plurality of said laser light spots, so as to correspond to the light intensity thereof, whereby detection of tracking error signal is effected through comparison of light receiving outputs of the photo-detectors.
Claim 6
Dependent Claim
106 words
An optical information processing apparatus which comprises a substrate (201), an optical waveguide (202) formed on said substrate (201), means for irradiating a plurality of laser light spots onto a recording medium so as to introduce the reflected light into said optical waveguide (202), and a set of photo-detectors for subjecting to photo-electric conversion, the reflected light introduced into said optical waveguide (202) for each reflected light ray corresponding to each spot of the plurality of said laser light spots, so as to correspond to the light intensity thereof, whereby detection of tracking error signal is effected through comparison of light receiving outputs of the photo-detectors.
References Cited (Backward Citations)
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