US5760860A
Expired / Lapsed
US
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Electro-optic scattering type devices with color polariser for switchable color
Assignee: Qinetiq Ltd
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Filing: 1994-02-17
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Granted: 1998-06-02
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Expires: 2014-02-17
Abstract
Abstract An electro-optic color device including a layer of polymer dispersed liquid crystal (7), with polarizers on either side (9,10), at least one being colored. By applying a voltage across the polymer dispersed liquid crystal cell (PDLC), the cell is switched from a scattering to a non-scattering state or vice-versa, and the color of the transmitted light is controlled. Applications include membrane switches.
Inventors
- 👤 Ian Robert Mason
- 👤 Damien Gerard McDonnell
- 👤 Sarah Caroline Guy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:28
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/133533; G02F1/1334; G02F1/137; G02F1/13756; G02F2203/00; G02F2203/34
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
84 words
An electro-optic colour device comprising a layer of a light modulating material which comprises a layer of polymer matrix within which is dispersed a liquid crystal composition, said layer of light modulating material positioned between at least two polarisers at least one of the polarisers being coloured, and means for applying an electric field to the light modulating material, the arrangement being such that the colour of light transmitted by the device is modulated by an electric field applied to the light modulating material.
Claim 2
Dependent Claim
84 words
An electro-optic colour device comprising a layer of a light modulating material which comprises a layer of polymer matrix within which is dispersed a liquid crystal composition, said layer of light modulating material positioned between at least two polarisers at least one of the polarisers being coloured, and means for applying an electric field to the light modulating material, the arrangement being such that the colour of light transmitted by the device is modulated by an electric field applied to the light modulating material.
Claim 3
Dependent Claim
20 words
A device according to claim 1 wherein the liquid crystal composition is dispersed within the polymer matrix in discrete droplets.
Claim 4
Dependent Claim
17 words
A device according to claim 1 wherein the polymer matrix consists of a matrix of interconnecting pores.
Claim 5
Dependent Claim
33 words
A device according to claim 1 wherein the layer of light modulating material is sandwiched between two transparent electrode structures the electrode structures being mounted on the inner surface of two transparent substrates.
Claim 6
Dependent Claim
17 words
A device according to claim 4, wherein the electrode structures are formed as a 7-bar numeric display.
Claim 7
Dependent Claim
17 words
A device according to claim 4, wherein the electrode structures are formed as row and column electrodes.
Claim 8
Dependent Claim
17 words
A device according to claim 4, wherein the electrode structures are formed as an r, θ pattern.
Claim 9
Dependent Claim
22 words
A device according to any one of claim 1 wherein the light modulating material is from 0.5 μm to 500 μm thick.
Claim 10
Dependent Claim
22 words
A device according to any one of claim 1 wherein the light modulating material is from 1.0 μm to 250 μm thick.
Claim 11
Dependent Claim
22 words
A device according to any one of claim 1 wherein the light modulating material is from 2.0 μm to 20 μm thick.
Claim 12
Dependent Claim
19 words
A device according to claim 1 wherein the coloured polariser comprises at least two sheets of coloured polarising material.
Claim 13
Dependent Claim
24 words
A device according to claim 11 wherein the two colour polarisers are arranged at an angle of from 60° to 120° to each other.
Claim 14
Dependent Claim
19 words
A device according to claim 12 wherein the two colour polarisers are arranged at substantially 90° to each other.
Claim 15
Dependent Claim
50 words
A device according to claim 1 wherein the relationship of the non-coloured polariser to the coloured polariser is such that the angle subtended by the non-colour polariser to one of the coloured polarisers is 0°-5° and the angle subtended by the non-colour polariser to the other colour polariser is 85°-95°.
Claim 16
Dependent Claim
99 words
A device according to claim 1 wherein the liquid crystal composition is a mixture of at least two compounds, at least one of the said compounds having a general formula I: ##STR15## wherein n is 1 or 2, the fluorine substituents may be in any of the available substitution positions and R 1 is C 1-12 alkynyl, hydrogen, R, RO or RCO where R is alkyl or perfluoroalkyl and at least one other of said compounds has a general formula II: ##STR16## wherein R 2 is hydrogen or C 1-12 alkyl or alkoxy and m is 0 or 1.
Claim 17
Dependent Claim
34 words
A device according to claim 15 wherein the composition additionally includes one or more compounds of formula III ##STR17## wherein R 3 is C 1-12 alkyl or alkoxy and l is 0 or 1.
Claim 18
Dependent Claim
19 words
A device according to claim 15 wherein at least one compound of the composition has the following formula: ##STR18##
Claim 19
Dependent Claim
79 words
A device according to any one of claim 15 wherein the composition includes one or more compounds selected from the following: ##STR19## wherein each of R 4 , R 5 , R 51 , R 6 and R 7 is independently C 1-12 alkyl or alkoxy, rings A and B are independently phenyl or cyclohexyl; p,q,r and s are each independently 1 or 2; and the fluorine substituent in VI may be in any of the available substitution positions.
Claim 20
Dependent Claim
32 words
A device according to claim 18 wherein compounds of Formulae IV, VI and VII are respectively: ##STR20## where R 4 , R 6 and R 7 are as defined in claim 18.
Claim 21
Dependent Claim
26 words
A device according to claim 1 wherein the polymer matrix is selected from one or more of epoxy resins, polyvinyl polymers, polyacrylates, polyurethanes polyesters and polyarylalkenes.
Claim 22
Dependent Claim
19 words
A device according to claim 1 wherein the polymer matrix is formed from a polymerised high internal phase emulsion.
Claim 23
Dependent Claim
15 words
A device according to claim 1 wherein the device is operated in a reverse mode.
Claim 24
Dependent Claim
87 words
An electro-optic colour device comprising a layer of a light modulating material which comprises a layer of polymer matrix within which is dispersed a liquid crystal composition, said layer of light modulating material positioned between at least two polarisers at least one of the polarisers being coloured, and means for applying an electric field across the light modulating material, the arrangement being such that by switching the light modulating material between scattering and non-scattering states there results a change in colour of light transmitted by the device.
Claim 25
Dependent Claim
87 words
An electro-optic colour device comprising a layer of a light modulating material which comprises a layer of polymer matrix within which is dispersed a liquid crystal composition, said layer of light modulating material positioned between at least two polarisers at least one of the polarisers being coloured, and means for applying an electric field across the light modulating material, the arrangement being such that by switching the light modulating material between scattering and non-scattering states there results a change in colour of light transmitted by the device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-01 | 2001-12-01 | 2002-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-01 | 2005-12-01 | 2006-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-01 | 2009-12-01 | 2010-06-02 | $7700.00 | Window Closed / Lapsed |