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EP0336328A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Apparatus for optically recording and reproducing information

Assignee: Nippon Conlux Co Ltd
•
Filing: 1989-04-02
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Granted: —
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Expires: 2009-04-02
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Abstract

Abstract An apparatus for optically recording and reproducing information in and from an optical information recording medium having a guide track. The apparatus uses an optical head having a diffraction grating, for recording and reproducing information. In recording information, a zero-order diffraction light beam from the diffraction grating is used for the information recording, and plus/minus first-order diffraction light beams from the diffraction grating are used for the tracking. In reproducing information, the zero-order diffraction light beam is used for the tracking, and higher- and odd-order diffraction light beams including at least plus/minus first-order diffraction light beams are used for information reproduction.

Inventors

  • 👤 Kazuo Noda
  • 👤 Koichi Yamazaki

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-04 23:46
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/14; G11B7/002; G11B7/0033; G11B7/08; G11B7/09; G11B7/0938; G11B7/13; G11B7/135; G11B7/0901; G11B7/0903

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 85 words
An apparatus for optically recording and reproducing information which uses an optical head having a diffraction grating and an optical information recording medium having a guide track, wherein in recording information, a zero-order diffraction light beam is used for information recording and plus/minus first-order diffraction light beams are used for tracking, and in reproducing information, said zero-order diffraction light beam is used for tracking and higher and odd order diffraction light beams including at least plus/minus first-order diffraction light beams are used for reproducing information.
Claim 2
Independent Claim 85 words
An apparatus for optically recording and reproducing information which uses an optical head having a diffraction grating and an optical information recording medium having a guide track, wherein in recording information, a zero-order diffraction light beam is used for information recording and plus/minus first-order diffraction light beams are used for tracking, and in reproducing information, said zero-order diffraction light beam is used for tracking and higher and odd order diffraction light beams including at least plus/minus first-order diffraction light beams are used for reproducing information.
Claim 3
Dependent Claim 24 words
An apparatus according to claim 1, wherein said zero-order diffraction light beam is used for focussing both for the information recording and information reproducing.
Claim 4
Dependent Claim 55 words
An apparatus according to claim 1, wherein in reproducing information a plurality of information signals reproduced by using said higher- and odd-order diffraction light beams including at least plus/minus first-order diffraction light beams are stored in a plurality of memories and thereafter, said information signals are read from said plurality of memories in time sequence.

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