Patent US1994228A successfully refreshed from Google Patents.
US3703329A
Expired / Lapsed
US
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Liquid crystal color display
Assignee: RCA Corp
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Filing: 1969-12-29
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Granted: 1972-11-21
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Expires: 1989-12-29
Abstract
Abstract A color display system capable of producing essentially all the colors of the visible spectrum comprises three cells each including a solution consisting of a pleochroic dye in a nematic liquid crystal composition. Each of the solutions can change its transmission of polarized white light in response to an electric field so as to change the color appearance of the solution. One solution of the system can change in appearance from color less to magenta, another from colorless to cyan, and a third from colorless to yellow. The system includes means for applying an electric field separately to each of the solutions and means for passing polarized white light successively through each solution.
Inventors
- 👤 Joseph Anthony Castellano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:23
CPC Classifications
G; G09; G09F; G09F13/00; G09F13/24; C; C09; C09K; C09K19/00; C09K19/52; C09K19/60; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1347; G02F1/13475
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
111 words
A color display system comprising three cells arranged in tandem, each cell containing a solution comprising a pleochroic dye dissolved in a nematic liquid crystal composition, each of said solutions having the characteristic of changing in color in response to an electric field when polarized white light is passed therethrough, wherein a. said pleochroic dye of said first cell consists of a mixture of indophenol blue and 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene, b. said pleochroic dye of said second cell consists of 2-amino-8-hydroxy-1-azonaphthyl-(p) 4''-benzonitrile, c. said pleochroic dye of said third cell consists of 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene, and d. electrode means for varying the color of each of said cells when polarized white light is passed therethrough.
Claim 2
Dependent Claim
111 words
A color display system comprising three cells arranged in tandem, each cell containing a solution comprising a pleochroic dye dissolved in a nematic liquid crystal composition, each of said solutions having the characteristic of changing in color in response to an electric field when polarized white light is passed therethrough, wherein a. said pleochroic dye of said first cell consists of a mixture of indophenol blue and 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene, b. said pleochroic dye of said second cell consists of 2-amino-8-hydroxy-1-azonaphthyl-(p) 4''-benzonitrile, c. said pleochroic dye of said third cell consists of 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene, and d. electrode means for varying the color of each of said cells when polarized white light is passed therethrough.
Claim 3
Dependent Claim
32 words
The color display system recited in claim 1 wherein the total concentration of dye in said nematic liquid crystal composition of each of said cells is between 1 and 2 weight percent.
Claim 4
Dependent Claim
57 words
The color display system recited in claim 1 wherein the nematic liquid crystal composition of each of said cells comprises at least one member of the group consisting of alkoxybenzylidene anils and acyloxybenzylidine anils wherein the alkoxy radical has from one to seven carbon atoms and wherein said acyloxy radical has from two to seven carbon atoms.
Claim 5
Dependent Claim
27 words
The color display system recited in claim 1 wherein the nematic liquid crystal composition of each cell comprises a mixture consisting essentially of p-hexoxybenzylidene-p''-aminobenzonitrile, p-hexanoylbenzylidene-p''-aminobenzonitrile, and p-heptanoylbenzylidene-p''-aminobenzonitrile.
Claim 6
Dependent Claim
131 words
A color display system comprising three cells arranged in tandem, each cell containing a solution comprising a pleochroic dye dissolved in a nematic liquid crystal composition, each of said solutions having the characteristic of changing in color in response to an electric field when polarized white light is passed therethrough, a. said pleochroic dye of said firsT cell is selected from the group consisting of a mixture of indophenol blue and 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene and of N,N''-dimethyl-indigo, b. said pleochroic dye of said second cell is selected from the group consisting of 2-amino-8-hydroxy-1-azonaphthyl-4''-benzonitrile and N,N''-dipalmitoylindigo, c. said pleochroic dye of said third cell is selected from the group consisting of 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene and p-nitrobenzylidenephenylhydrazone, and d. electrode means for varying the color of each of said cells when polarized white light is passed therethrough.
Claim 7
Dependent Claim
131 words
A color display system comprising three cells arranged in tandem, each cell containing a solution comprising a pleochroic dye dissolved in a nematic liquid crystal composition, each of said solutions having the characteristic of changing in color in response to an electric field when polarized white light is passed therethrough, a. said pleochroic dye of said firsT cell is selected from the group consisting of a mixture of indophenol blue and 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene and of N,N''-dimethyl-indigo, b. said pleochroic dye of said second cell is selected from the group consisting of 2-amino-8-hydroxy-1-azonaphthyl-4''-benzonitrile and N,N''-dipalmitoylindigo, c. said pleochroic dye of said third cell is selected from the group consisting of 4-butoxybenzylidene-4''-amino-4''''-nitroazobenzene and p-nitrobenzylidenephenylhydrazone, and d. electrode means for varying the color of each of said cells when polarized white light is passed therethrough.
Claim 8
Dependent Claim
26 words
The color display system recited in claim 5 wherein the concentration of pleochroic dye in said nematic liquid crystal composition is from 1-5 percent by weight.
Claim 9
Dependent Claim
57 words
The color display system recited in claim 5 wherein the nematic liquid crystal composition of each of said cells comprises at least one member of the group consisting of alkoxybenzylidene anils and acyloxybenzylidene anils wherein the alkoxy radical has from one to seven carbon atoms and wherein said acyloxy radical has from two to seven carbon atoms.
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |