US4969142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reproduction of optically recorded signal
Assignee: Panasonic Holdings Corp
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Filing: 1989-05-12
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Granted: 1990-11-06
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Expires: 2009-05-12
Abstract
Abstract In reproduction of signal recorded on an optical disk by irradiation of laser light beam thereon, interference between reflected diffracted light of +1th order or -1th order and reflected diffracted light of 0th order is coersively induced, and by detecting the interference light, a high frequency signal can be reproduced.
Inventors
- 👤 Michiyoshi Nagashima
- 👤 Yoshinari Takemura
- 👤 Kazuaki Obara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:56
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/004; G11B7/005; G11B7/12; G11B7/135
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
A method for reproducing a signal recorded in optical form comprising the steps of: irradiating a laser beam focused on a recorded surface of an optical disk through an objective lens, guiding a first part of a reflected light from said recorded surface through said objective lens, and guiding a second part of said reflected light from said recorded surface through a sub-optical path being outward from said objective lens, making interference between said first part of said reflected light and said second part of said reflected light to produce at least one interference light, and photo-detecting said interference light to reproduce said signal recorded in optical form.
Claim 2
Independent Claim
108 words
A method for reproducing a signal recorded in optical form comprising the steps of: irradiating a laser beam focused on a recorded surface of an optical disk through an objective lens, guiding a first part of a reflected light from said recorded surface through said objective lens, and guiding a second part of said reflected light from said recorded surface through a sub-optical path being outward from said objective lens, making interference between said first part of said reflected light and said second part of said reflected light to produce at least one interference light, and photo-detecting said interference light to reproduce said signal recorded in optical form.
Claim 3
Dependent Claim
29 words
A method for reproducing a signal recorded in optical form in accordance with claim 1, wherein said sub-optical path passes through a light convergence lens means and prism means.
Claim 4
Dependent Claim
27 words
A method for reproducing a signal recorded in optical form in accordance with claim 1, wherein said sub-optical path passes through a single mode optical fiber means.
Claim 5
Independent Claim
112 words
An apparatus for reproducing a signal recorded in optical form comprising: means for irradiating a laser beam focused on a recorded surface of an optical disk through an objective lens, means for guiding a first part of a reflected light from said recorded surface through said objective lens, and guiding a second part of said reflected light from said recorded surface through a sub-optical path being outward from said objective lens, means for making interference between said first part of said reflected light and second part of said reflected light to produce at least one interference light, and means for photo-detecting said interference light to reproduce a signal recorded in optical form.
Claim 6
Independent Claim
112 words
An apparatus for reproducing a signal recorded in optical form comprising: means for irradiating a laser beam focused on a recorded surface of an optical disk through an objective lens, means for guiding a first part of a reflected light from said recorded surface through said objective lens, and guiding a second part of said reflected light from said recorded surface through a sub-optical path being outward from said objective lens, means for making interference between said first part of said reflected light and second part of said reflected light to produce at least one interference light, and means for photo-detecting said interference light to reproduce a signal recorded in optical form.
Claim 7
Dependent Claim
27 words
An apparatus for reproducing a signal recorded in optical form in accordance with claim 4, wherein said sub-optical path comprises light convergence lens means and prism means.
Claim 8
Dependent Claim
25 words
An apparatus for reproducing a signal recorded in optical form in accordance with claim 4, wherein said sub-optical path comprises single mode optical fiber 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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |