US4766303A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical information system having a birefringence plate movably disposed in accordance with the detected light intensity
Assignee: Panasonic Holdings Corp
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Filing: 1987-05-13
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Granted: 1988-08-23
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Expires: 2007-05-13
Abstract
Abstract An optical information system includes an optical source emitting light. An information recording member is exposed to the emitted light. A beam splitter disposed between the light emitting source and the information recording member separates light reflected by the information recording member and light traveling from the light emitting source to the information recording member. A device detects intensity of the separated reflected light. A birefringence plate is movably disposed between the light emitting source and the information recording member. The birefringence plate is moved in accordance with the detected intensity of the separated reflected light.
Inventors
- 👤 Keiichi Yoshizumi
- 👤 Akira Matsubara
- 👤 Takao Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:11
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/095; G11B7/12; G11B7/135; G11B7/1365
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
102 words
An optical information system comprising: (a) means for emitting light; (b) an information recording member exposed to the emitted light; (c) a beam splitter disposed between the light emitting means and the information recording member for separating light reflected by the information recording member and light traveling from the light emitting means to the information recording member; (d) means for detecting intensity of the separated reflected light; (e) a birefringence plate movably disposed between the light emitting means and the information recording member; and (f) means for moving the birefringence plate in accordance with the detected intensity of the separated reflected light.
Claim 2
Dependent Claim
102 words
An optical information system comprising: (a) means for emitting light; (b) an information recording member exposed to the emitted light; (c) a beam splitter disposed between the light emitting means and the information recording member for separating light reflected by the information recording member and light traveling from the light emitting means to the information recording member; (d) means for detecting intensity of the separated reflected light; (e) a birefringence plate movably disposed between the light emitting means and the information recording member; and (f) means for moving the birefringence plate in accordance with the detected intensity of the separated reflected light.
Claim 3
Dependent Claim
26 words
The system of claim 1 wherein a direction of birefringence of the information recording member is parallel to a direction of birefringence of the birefringence plate.
Claim 4
Dependent Claim
26 words
The system of claim 1 wherein a direction of birefringence of the information recording member is perpendicular to a direction of birefringence of the birefringence plate.
Claim 5
Dependent Claim
24 words
The system of claim 1 wherein the birefringence plate moving means comprises a holder supporting the birefringence plate, and means for rotating the holder.
Claim 6
Dependent Claim
27 words
The system of claim 4 wherein the holder rotating means comprises a gear meshing with teeth formed on the holder, and a motor connected to the gear.
Claim 7
Dependent Claim
26 words
The system of claim 4 wherein the holder rotating means comprises a winding mounted on the holder, and a fixed magnet magnetically coupled to the winding.
Claim 8
Dependent Claim
13 words
The system of claim 1 wherein the birefringence plate comprises a quarter-wave plate.
Claim 9
Dependent Claim
25 words
The system of claim 1 wherein a direction of birefringence of the birefringence plate is inclined with respect to a surface of the birefringence plate.
Claim 10
Dependent Claim
106 words
An optical information system comprising: (a) means for emitting light; (b) an information recording member exposed to the emitted light; (c) a beam splitter disposed between the light emitting means and the information recording member for separating light reflected by the information recording member and light traveling from the light emitting means to the information recording member; (d) means for detecting intensity of the separated reflected light; (e) a birefringence plate movably disposed between the light emitting means and the information recording member; and (f) means for moving the birefringence plate to a position at which the detected intensity of the separated reflected light is maximized.
Claim 11
Dependent Claim
106 words
An optical information system comprising: (a) means for emitting light; (b) an information recording member exposed to the emitted light; (c) a beam splitter disposed between the light emitting means and the information recording member for separating light reflected by the information recording member and light traveling from the light emitting means to the information recording member; (d) means for detecting intensity of the separated reflected light; (e) a birefringence plate movably disposed between the light emitting means and the information recording member; and (f) means for moving the birefringence plate to a position at which the detected intensity of the separated reflected light is maximized.
Claim 12
Dependent Claim
26 words
The system of claim 9 wherein a direction of birefringence of the information recording member is parallel to a direction of birefringence of the birefringence plate.
Claim 13
Dependent Claim
26 words
The system of claim 9 wherein a direction of birefringence of the information recording member is perpendicular to a direction of birefringence of the birefringence plate.
Claim 14
Dependent Claim
24 words
The system of claim 9 wherein the birefringence plate moving means comprises a holder supporting the birefringence plate, and means for rotating the holder.
Claim 15
Dependent Claim
27 words
The system of claim 12 wherein the holder rotating means comprises a gear meshing with teeth formed on the holder, and a motor connected to the gear.
Claim 16
Dependent Claim
26 words
The system of claim 12 wherein the holder rotating means comprises a winding mounted on the holder, and a fixed magnet magnetically coupled to the winding.
Claim 17
Dependent Claim
13 words
The system of claim 9 wherein the birefringence plate comprises a quarter-wave plate.
Claim 18
Dependent Claim
25 words
The system of claim 9 wherein a direction of birefringence of the birefringence plate is inclined with respect to a surface of the birefringence plate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |