US4606612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical phase filter using liquid crystal
Assignee: Canon Inc
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Filing: 1984-06-01
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Granted: 1986-08-19
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Expires: 2004-06-01
Abstract
Abstract An optical phase filter includes a liquid crystal layer whose configuration changes between the homogeneous and homeotropic configurations depending upon whether or not an electric field is applied thereacross. A pair of transparent electrodes apply the electric field to the liquid crystal layer. At least one of the transparent electrodes is provided with a great number of holes distributed at random over its entire surface, whereby the optical performance and particularly the MTF value of the light passing through the liquid crystal layer due to the double-refracting property of the liquid crystal layer is made variable.
Inventors
- 👤 Kiyoshi Iizuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:29
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/20; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/137; G02F1/139; G02F1/1393
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
34 words
An optical phase filter comprising: a liquid crystal layer; and a transparent electrode for applying an electric field to said liquid crystal layer, said transparent electrode having a plurality of openings distributed at random.
Claim 2
Dependent Claim
34 words
An optical phase filter comprising: a liquid crystal layer; and a transparent electrode for applying an electric field to said liquid crystal layer, said transparent electrode having a plurality of openings distributed at random.
Claim 3
Dependent Claim
33 words
A filter according to claim 1, wherein said liquid crystal layer changes its structure between a homogeneous array and a homeotropic array depending upon whether or not the electric field is applied thereto.
Claim 4
Dependent Claim
71 words
An optical phase filter comprising: a liquid crystal layer first and second transparent electrodes for applying an electric field to said liquid crystal layer, said first and second transparent electrodes having a plurality of openings distributed at random, the openings of said first transparent electrode being different in size from the openings of said second transparent electrode; and means for selectively actuating one of said first and said second transparent electrodes.
Claim 5
Dependent Claim
71 words
An optical phase filter comprising: a liquid crystal layer first and second transparent electrodes for applying an electric field to said liquid crystal layer, said first and second transparent electrodes having a plurality of openings distributed at random, the openings of said first transparent electrode being different in size from the openings of said second transparent electrode; and means for selectively actuating one of said first and said second transparent electrodes.
Claim 6
Dependent Claim
24 words
A filter according to claim 3, wherein said first and said second transparent electrodes are arranged on different sides of said liquid crystal layer.
Claim 7
Dependent Claim
30 words
A filter according to claim 3, wherein said first and said second transparent electrodes are arranged on the same side of said liquid crystal layer in an electrically insulated manner.
Claim 8
Dependent Claim
35 words
A filter according to claim 4 or 5, wherein said liquid crystal layer changes its structure between a homogeneous array and a homeotropic array depending upon whether or not the electric field is applied thereto.
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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |