Patent EP0421628A2 successfully refreshed from Google Patents.
EP0421628A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Projection type liquid crystal display device
Assignee: Seiko Epson Corp
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Filing: 1990-09-17
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Granted: —
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Expires: 2010-09-17
Abstract
Abstract The invention provides a projection type liquid crystal display device having a light source (1), light separation means (4) for separating light from the light source, a liquid crystal light valve (8) for modulating light from the light separation means, light synthesising means (9) for synthesising modulated light from the liquid crystal light valve, and a projection lens (12) for projecting light from the light synthesising means. A polarising beam splitter (2) is arranged between the light source and the light separation means to separate incident light into two polarised light components perpendicular to each other. A polarisation direction converter (3) is arranged to receive the polarised light components from the polarising beam splitter and to convert the components to have the same polarisation direction for projecting them as a substantially parallel beam.
Inventors
- 👤 Johji Karasawa
- 👤 Junishirou Shinozaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:53
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315; H04N9/3167; G; G03; G03B; G03B21/00; G03B21/005; G03B21/006; G09; G09F; G09F19/00; G09F19/12; G09F19/18; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
A liquid crystal display device having a light source (1), light separation means (4) for separating light from said light source, a liquid crystal light valve (8) for modulating light from said light separation means, light synthesising means (9) for synthesising modulated light from said liquid crystal light valve, and a projection lens (12) for projecting light from said light synthesising means, and characterised by a polarising beam splitter (2) arranged between said light source and said light separation means to separate incident light into two polarised light components perpendicular to each other, and polarisation direction converting means (3) for converting the two polarised light components to have the same polarisation direction and for projecting them as a substantially parallel beam.
Claim 2
Dependent Claim
121 words
A liquid crystal display device having a light source (1), light separation means (4) for separating light from said light source, a liquid crystal light valve (8) for modulating light from said light separation means, light synthesising means (9) for synthesising modulated light from said liquid crystal light valve, and a projection lens (12) for projecting light from said light synthesising means, and characterised by a polarising beam splitter (2) arranged between said light source and said light separation means to separate incident light into two polarised light components perpendicular to each other, and polarisation direction converting means (3) for converting the two polarised light components to have the same polarisation direction and for projecting them as a substantially parallel beam.
Claim 3
Dependent Claim
46 words
A display device according to claim 1 characterised in that said polarising beam splitter comprises a cubic polariser having a pair of right-angled prisms, whose sloping surfaces are coated with a dielectric laminated coating layer (17) and are adhered to each other with said coating layer.
Claim 4
Dependent Claim
46 words
A display device according to claim 1 characterised in that said polarising beam splitter comprises a single glass plate, or a plurality of glass plates (20) laminated in parallel, arranged such that the angle of the incident light on said glass plate(s) represents a polarisation angle.
Claim 5
Dependent Claim
28 words
A display device according to any of claims 1 to 3 characterised in that said polarisation direction converting means comprises at least one light reflector (23 to 26).
Claim 6
Dependent Claim
24 words
A display device according to any of claims 1 to 3 characterised in that said polarisation direction converting means comprises a λ/4 plate (27).
Claim 7
Dependent Claim
24 words
A display device according to any of claims 1 to 3 characterised in that said polarisation direction converting means comprises a λ/2 plate (35).
Claim 8
Dependent Claim
36 words
A display device according to any of claims 1 to 6 characterised in that the two polarised light components are arranged to be projected substantially in parallel by means of a wedge-type light reflector (31, 36).
Claim 9
Dependent Claim
39 words
A display device according to any of claims 1 to 7 characterised in that the two polarised light components projected substantially in parallel are arranged to be condensed with a lens (42, 43) for projection into said light valve.
Claim 10
Dependent Claim
36 words
A display device according to any of claims 1 to 8 characterised in that the two polarised light components are each arranged to be irradiated onto a respective half of the aperture of said light valve.
References Cited (Backward Citations)
No citation records indexed.
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