US3904797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Homeotropic alignment of liquid crystals in a display cell by baked on ionic surfactants
Assignee: Boeing North American Inc
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Filing: 1973-05-07
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Granted: 1975-09-09
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Expires: 1993-05-07
Abstract
Abstract An ionic surfactant in a solvent is coated on the interior walls of a cell for a liquid crystal display. After evaporation of the solvent, the cell is heated to bake on the deposited surfactant. Ionically doped nematic liquid crystals introduced into the cell immediately align themselves homeotropically (perpendicular to the wall). This increases the liquid crystal contrast ratio and eliminates the slight contrast normally present in doped liquid crystals even in the quiescent state.
Inventors
- 👤 Jr Freeman B Jones
- 👤 Ronald M Govan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133703; B; B44; B44F; B44F1/00; B44F1/08; B44F1/14; C; C09; C09K; C09K19/00; C09K19/52; C09K19/58; G02F1/133711; G02F1/133719
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
79 words
A LIQUID CRYSTAL DISPLAY CELL HAVING A FIRST IONIC DOPANT BAKED ONTO THE WALLS THEREOF AND CONTAINING A LIQUID CRYSTAL MATERIAL CONSISTING ESSENTIALLY OF 4-METHYOXYBENZYLIDENE-4''-N BUTYLANILINE AND 4-ETHOXYBENZYLIDENE-4''-N-BUTYLANILINE, SAID LIQUID CRYSTAL MATERIAL BEING DOPED WITH A SECOND IONIC DOPANT, SAID FIRST AND SECOND IONIC DOPANT HAVING THE GENERAL FORMULA R1 R2 R3R4N+B-(R5)4 WHERE R1, R2, R3, R4, AND R5 ARE EACH SELECTED FROM THE GROUP CONSISTING OF PHENYL, BIPHENYL AND CH3(CH2)N, WHERE N IS A POSITIVE INTEGER OR ZERO.
Claim 2
Dependent Claim
79 words
A LIQUID CRYSTAL DISPLAY CELL HAVING A FIRST IONIC DOPANT BAKED ONTO THE WALLS THEREOF AND CONTAINING A LIQUID CRYSTAL MATERIAL CONSISTING ESSENTIALLY OF 4-METHYOXYBENZYLIDENE-4''-N BUTYLANILINE AND 4-ETHOXYBENZYLIDENE-4''-N-BUTYLANILINE, SAID LIQUID CRYSTAL MATERIAL BEING DOPED WITH A SECOND IONIC DOPANT, SAID FIRST AND SECOND IONIC DOPANT HAVING THE GENERAL FORMULA R1 R2 R3R4N+B-(R5)4 WHERE R1, R2, R3, R4, AND R5 ARE EACH SELECTED FROM THE GROUP CONSISTING OF PHENYL, BIPHENYL AND CH3(CH2)N, WHERE N IS A POSITIVE INTEGER OR ZERO.
Claim 3
Dependent Claim
23 words
The display cell of claim 3 wherein the ionic dopant in the liquid crystal has a concentration in the range of 10-100 ppm.
Claim 4
Dependent Claim
17 words
The display cell of claim 1 wherein the first and second ionic dopants contain (C18H37)2(CH3)2N B (C6H5)4.
Claim 5
Dependent Claim
14 words
The display cell of claim 3 wherein the first ionic dOpant further contains (C18H37)2CH3N.
Claim 6
Dependent Claim
22 words
The display cell of claim 4 wherein the liquid crystal contains substantially 55 percent 4-methoxybenzylidene-4''-n-butylaniline and substantially 45 percent 4-ethoxybenzylidene-4''-n-butylaniline by weight.
Claim 7
Dependent Claim
28 words
The display cell of claim 5 wherein the liquid crystal is doped with p-aminophenol and p-toluenesulfonic acid; and the ionic dopant is present in concentrations of 10-100 ppm.
References Cited (Backward Citations)
US3799651A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-08 | 1979-03-10 | 1979-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-08 | 1983-03-10 | 1983-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-08 | 1987-03-10 | 1987-09-09 | $7700.00 | Window Closed / Lapsed |