Patent US5020065A successfully refreshed from Google Patents.
US5020065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor laser device
Assignee: Mitsubishi Electric Corp
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Filing: 1990-01-08
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Granted: 1991-05-28
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Expires: 2010-01-08
Abstract
Abstract A semiconductor laser device comprise a semiconductor laser light emitting element, and a cap that covers and hermetically seals the laser light emitting element in a package. Laser light emitted from the element goes out through a hole formed in the top wall of the cap. A reflected light blocking element is disposed in the hole in the top wall of the cap. The reflected light blocking element includes a twisted-nematic liquid crystal cell and a pair of polarizers between which the twisted-nematic liquid crystal cell is disposed.
Inventors
- 👤 Katsuhisa Tada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:30
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/005; H01S3/0064; G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4204; G02B6/4207; G02B6/4208
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
81 words
A semiconductor laser device comprising: a laser element which emits laser light; a cap covering and hermetically sealing said laser element within a package, said cap having, in its top wall, a hole through which laser light is emitted; and reflected light blocking means disposed in said hole in said top wall of said cap wherein said reflected light blocking means comprises a twisted-nematic liquid crystal cell and a pair of polarizers between which said twisted-nematic liquid crystal cell is disposed.
Claim 2
Dependent Claim
81 words
A semiconductor laser device comprising: a laser element which emits laser light; a cap covering and hermetically sealing said laser element within a package, said cap having, in its top wall, a hole through which laser light is emitted; and reflected light blocking means disposed in said hole in said top wall of said cap wherein said reflected light blocking means comprises a twisted-nematic liquid crystal cell and a pair of polarizers between which said twisted-nematic liquid crystal cell is disposed.
Claim 3
Dependent Claim
42 words
A semiconductor laser device according to claim 1 wherein said twisted-nematic liquid crystal cell rotates the plane of polarization of laser light by 45° as laser light passes through said cell, and the polarization directions of said polarizers are separated by 45°.
Claim 4
Dependent Claim
13 words
A semiconductor laser device according to claim 1 wherein said polarizers comprise calcite.
Claim 5
Dependent Claim
13 words
A semiconductor laser device according to claim 2 wherein said polarizers comprise calcite.
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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) | 1994-05-27 | 1994-11-26 | 1995-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-27 | 1998-11-26 | 1999-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-27 | 2002-11-26 | 2003-05-28 | $7700.00 | Window Closed / Lapsed |