Patent US3994565A successfully refreshed from Google Patents.
US3994565A
Expired / Lapsed
US
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Device for displaying characters having a twisted nematic liquid crystal
Assignee: US Philips Corp
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Filing: 1975-06-11
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Granted: 1976-11-30
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Expires: 1995-06-11
Abstract
Abstract A device for displaying characters on a background of a different color which includes a liquid crystal having a twisted nematic configuration and two sources of polarized light of different colors the directions of polarization of which are at right angles to each other.
Inventors
- 👤 Cornelis Zeger Van Doorn
- 👤 Johannes Leo Antonius Marie Heldens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:09
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133621
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
A device for displaying characters, comprising: a layer of nematic liquid crystal between two transparent supporting plates, said crystal in the undisturbed state having a twisted configuration and said supporting plates including electrodes arranged for creating electric field disturbing said twisted configuration according to a desired character; two light sources of linearly polarized light having different colors and directions of polarization which are at right angles to each other; and means for analyzing polarized light passed through said crystal.
Claim 2
Independent Claim
79 words
A device for displaying characters, comprising: a layer of nematic liquid crystal between two transparent supporting plates, said crystal in the undisturbed state having a twisted configuration and said supporting plates including electrodes arranged for creating electric field disturbing said twisted configuration according to a desired character; two light sources of linearly polarized light having different colors and directions of polarization which are at right angles to each other; and means for analyzing polarized light passed through said crystal.
References Cited (Backward Citations)
US3863246A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |