Patent US3915554A successfully refreshed from Google Patents.
US3915554A
Expired / Lapsed
US
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Liquid crystal display device with controllable color
Assignee: Suwa Seikosha KK
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Filing: 1974-02-13
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Granted: 1975-10-28
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Expires: 1994-02-13
Abstract
Abstract In a liquid crystal display device the liquid crystal material is of positive dielectric anisotropy and the walls of the cell are unidirectionally rubbed. By orienting the cell walls so that the rubbing directions lie at a suitable angle to each other and by varying the voltage applied to transparent electrodes on the inner faces of said cell walls, it becomes possible to control the hue of the light transmitted by said cell, and thereby the color of the resultant display.
Inventors
- 👤 Shuji Maezawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:38
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/133531; G02F2203/00; G02F2203/34
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
173 words
An electro-optical color display device comprising, a liquid crystal cell having a pair of opposed walls, a nematIc liquid crystal composition having a positive dielectric anisotropy in said cell, the inner faces of the walls of said cell having been unidirectionally rubbed and being positioned with the rubbing directions at an angle of 30* - 60* or 120* - 150* to each other and having transparent conductive elements on same connectible to an external source of variable voltage, and a polarizer and an analyzer sandwiching said cell, the polarization axis of said polarizer being at 90* to the rubbing direction of the nearer wall of said cell and 90* to the polarization axis of said analyzer whereby a voltage applied by said source to said elements having a value less than that required to produce a substantially homeotropic alignment in said liquid crystal composition results in the transmission of colored light through said analyzer for white light incident on said polarizer, said transmitted color being a function of the value of said voltage.
Claim 2
Dependent Claim
173 words
An electro-optical color display device comprising, a liquid crystal cell having a pair of opposed walls, a nematIc liquid crystal composition having a positive dielectric anisotropy in said cell, the inner faces of the walls of said cell having been unidirectionally rubbed and being positioned with the rubbing directions at an angle of 30* - 60* or 120* - 150* to each other and having transparent conductive elements on same connectible to an external source of variable voltage, and a polarizer and an analyzer sandwiching said cell, the polarization axis of said polarizer being at 90* to the rubbing direction of the nearer wall of said cell and 90* to the polarization axis of said analyzer whereby a voltage applied by said source to said elements having a value less than that required to produce a substantially homeotropic alignment in said liquid crystal composition results in the transmission of colored light through said analyzer for white light incident on said polarizer, said transmitted color being a function of the value of said voltage.
Claim 3
Dependent Claim
30 words
The electro-optical display device as defined in claim 1, further comprising a light source with lens means disposed for directing light from said source at near-normal incidence toward said polarizer.
Claim 4
Dependent Claim
22 words
The electro-optical display device as defined in claim 2 further comprising another lens means disposed for focussing light emerging from said analyzer.
Claim 5
Dependent Claim
26 words
The electro-optical display device as defined in claim 1, wherein said liquid crystal composition is in the liquid crystal state over a range including room temperature.
Claim 6
Dependent Claim
19 words
The electro-optical display device as defined in claim 1, wherein the walls of said cell are of borosilicate glass.
Claim 7
Independent Claim
200 words
A method for controlling the color of a nematic liquid crystal display device wherein light is passed through a liquid crystal cell having a pair of opposed walls, a nematic liquid crystal composition having a positive dielectric anisotropy in said cell, the inner faces of the walls of said cell having been unidirectionally rubbed and being positioned with the rubbing directions at an angle of 30* - 60* or 120* - 150* to each other, and said inner faces having transparent conductive elements on same connectible to an external voltage source, and a polarizer and an analyzer sandwiching said cell, the polarization axis of said polarizer being at 90* to the rubbing direction of the nearer wall of said cell and at 90* to the polarization axis of said analyzer, comprising the step of applying a control voltage to said transparent conductive elements whereby a voltage applied by said source to said elements having a value less than that required to produce a substantially homeotropic alignment in said liquid crystal composition results in the transmission of colored light through said analyzer for white light incident on said polarizer, said transmitted color being a function of the value of said voltage.
Claim 8
Independent Claim
200 words
A method for controlling the color of a nematic liquid crystal display device wherein light is passed through a liquid crystal cell having a pair of opposed walls, a nematic liquid crystal composition having a positive dielectric anisotropy in said cell, the inner faces of the walls of said cell having been unidirectionally rubbed and being positioned with the rubbing directions at an angle of 30* - 60* or 120* - 150* to each other, and said inner faces having transparent conductive elements on same connectible to an external voltage source, and a polarizer and an analyzer sandwiching said cell, the polarization axis of said polarizer being at 90* to the rubbing direction of the nearer wall of said cell and at 90* to the polarization axis of said analyzer, comprising the step of applying a control voltage to said transparent conductive elements whereby a voltage applied by said source to said elements having a value less than that required to produce a substantially homeotropic alignment in said liquid crystal composition results in the transmission of colored light through said analyzer for white light incident on said polarizer, said transmitted color being a function of the value of said voltage.
Claim 9
Dependent Claim
16 words
The method of claim 6, wherein said control voltage lies between about 3.0 and 8.0 volts.
Claim 10
Dependent Claim
9 words
The method of claim 6 wherein said voltage alternates.
Claim 11
Dependent Claim
15 words
The method of claim 6 wherein said voltage alternates at a rate of about 32Hz.
Claim 12
Dependent Claim
22 words
The method of claim 6, wherein light from a light source is directed by lens means at near-normal incidence at said polarizer.
Claim 13
Dependent Claim
17 words
The method of claim 10, wherein light emerging from said analyzer is focussed by another lens means.
Claim 14
Dependent Claim
55 words
The method of claim 6, wherein said voltage is varied between about 3.3 and 6.1 when the angle between the rubbed directions on said walls of said liquid crystal cell lies between 30* and 60*, and the voltage is varied between about 3.1 and 7.5 volts when said angle lies between about 130* and 160*.
Claim 15
Dependent Claim
18 words
The method of claim 6, wherein the distance between the walls of said cell is about 6 microns.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |