US3694053A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nematic liquid crystal device
Assignee: AT&T Inc
•
Filing: 1971-06-22
•
Granted: 1972-09-26
•
Expires: 1991-06-22
Abstract
Abstract A device characterized by an electronically-tunable optical birefringence over the range of 0.0 to 0.2 for applied voltages below 25 volts rms includes a thin film of a nematic liquid crystal. The tunable birefringence occurs below the threshold for dynamic scattering and is the result of electric-field-induced spatially-uniform molecular reorientation in a well-aligned nematic liquid crystal. Applications for such a cell include display elements, tunable retarders, color modulators and variable density filters.
Inventors
- 👤 Frederic Jay Kahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:22
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/13725; C; C09; C09K; C09K19/00; C09K19/52; C09K19/54; C09K19/56; G02F1/133; G02F1/1333; G02F1/1337; G02F1/139; G02F1/1393; G02F1/13712
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
22 words
A combination as in claim 1 wherein said means for initially orienting comprises a homeotropic-inducing additive mixed with said nematic liquid crystal.
Claim 2
Dependent Claim
30 words
A combination as in claim 2 wherein said nematic liquid crystal comprises MBBA and said means for initially orienting comprises 0.005 percent by weight of HMAB added to said MBBA.
Claim 3
Dependent Claim
30 words
A combination as in claim 1 wherein said means for initially orienting comprises homeotropic-inducing layers in contact with the opPosed major surfaces of said thin film of nematic liquid crystal.
Claim 4
Dependent Claim
33 words
A combination as in claim 1 wherein said means for imposing a preferred reorientation direction comprises electrode layers in contact with the opposed major surfaces of said thin film of nematic liquid crystal.
Claim 5
Dependent Claim
21 words
A combination as in claim 5 wherein said electrode layers have been selectively treated by rubbing them in the preferred direction.
Claim 6
Dependent Claim
24 words
A combination as in claim 5 further including means connected to said electrode layers for establishing in said thin film a variable electric field.
Claim 7
Dependent Claim
21 words
A combination as in claim 7 wherein said means connected to said electrode layers establishes therebetween a variable ac electric field.
Claim 8
Dependent Claim
169 words
A tunable birefringence device comprising a thin film of a nematic liquid crystal that is characterized by long molecules whose electric susceptibility perpendicular to the long axes of the molecules is greater than the electric susceptibility parallel to the long axes of the molecules, said thin film lying in an xy plane, means for establishing a variable ac electric field in said thin film in the z direction, which is perpendicular to said xy plane, means for quiescently ordering the molecules of said thin film in the absence of an electric field such that the long axes of substantially all of said molecules are aligned parallel to said z direction, and means for quiescently imposing a preferred orientation direction on the molecules of said thin film such that when an electric field is applied thereto a portion of the molecules of said thin film are rotated in a spatially-ordered manner to an orientation in which the long axes thereof are parallel to each other and to said xy plane.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |