Patent EP0470817A2 successfully refreshed from Google Patents.
EP0470817A2
Expired / Lapsed
EP
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Liquid crystal electro-optical device
Assignee: Seiko Epson Corp
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Filing: 1991-08-06
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Granted: —
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Expires: 2011-08-06
Abstract
Abstract The invention provides a liquid crystal electro-optical device of the reflective type. The device comprises a twisted nematic liquid crystal layer (104) sandwiched between two opposed substrates (101, 103), a polarising element (106) for polarising light entering the liquid crystal layer, and a reflective element (102) for reflecting light transmitted by the liquid crystal layer. The polarising element, the liquid crystal layer and the reflective element are arranged to co-operate in one state of the electro-optical device so as to convert the light between linearly polarised light at one surface of the liquid crystal layer and circularly polarised light at the other surface of the liquid crystal layer. Further, the direction of polarisation of light emerging from the liquid crystal layer is altered relative to the direction of polarisation of light entering the liquid crystal layer. <IMAGE>
Inventors
- 👤 Tomio c/o SEIKO EPSON CORPORATION Sonehara
- 👤 Osamu C/O Seiko Epson Corporation Okumura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 00:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/13363; G02F1/137; G02F1/139; G02F1/1396; G02F1/133553; G02F1/133638; G02F1/1397; G02F1/1398; G02F2202/00; G02F2202/40; G02F2203/00; G02F2203/02; G02F2413/00; G02F2413/01; G02F2413/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
132 words
A liquid crystal electro-optical device of the reflective-type having a twisted nematic liquid crystal layer (104) sandwiched between two opposed substrates (101, 103), a polarising element (106) for polarising light entering the liquid crysal layer, and a reflective element (102) for reflecting light transmitted by the liquid crystal layer, characterised in that the polarising element, the liquid crystal layer and the reflective element are arranged to co-operate in one state of the electro-optical device so as to convert the light between linearly polarised light at one surface of the liquid crystal layer and circularly polarised light at the other surface of the liquid crystal layer, and so as to alter the direction of polarisation of light emerging from the liquid crystal layer relative to that of light entering the liquid crystal layer.
Claim 2
Dependent Claim
115 words
An electro-optical device according to claim 1 characterised in that the polarising element is arranged to supply linearly polarised light to the liquid crystal layer, and in that the liquid crystal layer is arranged in said one state to convert the linearly polarised light from the polarising element to circularly polarised light for reflection by the reflective element and again to linearly polarised light after reflection for return to the polarising element, such that the plane of polarisation of the light emerging from the liquid crystal layer to the polarising element is rotated through 90° relative to the plane of polarisation of the linearly polarised light entering the liquid crystal layer from the polarising element.
Claim 3
Dependent Claim
42 words
An electro-optical device according to claim 2 characterised in that the polarising element is arranged to supply linearly polarised light to the liquid crystal layer at an angle to the molecular axis of the liquid crystal material adjacent to the polarising element.
Claim 4
Dependent Claim
107 words
An electro-optical device according to claim 1 characterised in that the polarising element is arranged to supply circularly polarised light to the liquid crystal layer, and in that the liquid crystal layer is arranged in said one state to convert the circularly polarised light from the polarising element to linearly polarised light for reflection by the reflective element and back to circularly polarised light for return to the polarising element, such that the circularly polarised light emerging from the liquid crystal layer to the polarising element is rotated in the opposite direction relative to the circularly polarised light entering the liquid crystal layer from the polarising element.
Claim 5
Dependent Claim
26 words
An electro-optical device according to any preceding claim characterised in that the reflective element is provided between the opposed substrates and adjacent the liquid crystal layer.
Claim 6
Dependent Claim
35 words
An electro-optical device according to any preceding claim characterised in that a part (1614) defining the surface of the liquid crystal layer adjacent the reflective element has a roughened surface facing the liquid crystal layer.
Claim 7
Dependent Claim
21 words
An electro-optical device according to any preceding claim further characterised by at least one layer (1505) of an optically anisotropic material.
Claim 8
Dependent Claim
73 words
A reflection-type liquid crystal electro-optical device with twisted nematic liquid crystal (104) sandwiched between two substrates (101, 103) disposed opposite each other, wherein a twisted nematic liquid crystal layer is employed that allows linearly polarised incident light to enter and become circularly polarised light at the reflecting surface (102) and then linearly polarised light after reflection whose plane of polarisation is rotated 90° from that of the incident light at the emission surface.
Claim 9
Dependent Claim
69 words
A reflection-type liquid crystal electro-optical device with twisted liquid crystal (1004) sandwiched between two substrates (1001, 1003) disposed opposite each other, wherein a twisted nematic liquid crystal layer is employed that allows circularly polarised incident light to enter and become linearly polarised light at the reflecting surface (1002) and then circularly polarised light after reflection that has been rotated opposite the incident circularly polarised light at the emission surface.
Claim 10
Dependent Claim
84 words
A reflection-type liquid crystal electro-optical device with twisted nematic liquid crystal (1515) sandwiched between two substrates (1511, 1512) disposed opposite each other, wherein the reflection-type liquid crystal electro-optical device comprises a liquid crystal cell (1501) made up of liquid crystals sandwiched between two substrates in a twisted orientation, one polarising plate (1502) that combines polarising elements and analyser elements, one reflecting element (1504), and at least one layer (1505) of an optically anisotropic material other than the liquid crystal of the liquid crystal cell.
References Cited (Backward Citations)
No citation records indexed.
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