Patent EP0488080A1 successfully refreshed from Google Patents.
EP0488080A1
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Projection type display apparatus with diaphragm
Assignee: AGC Inc
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Filing: 1991-11-22
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Granted: —
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Expires: 2011-11-22
Abstract
Abstract A projection type display apparatus comprises a light source optical system (16,17,18) having an anisotropic luminance distribution, a transparent-scattering type display element (13) for controlling light emitted from the light source optical system and a projection optical system (15) having an aperture (14) which projects the transmitted light, wherein the aperture of the projection optical system is an aperture having a non-circular opening which is disposed in the vicinity of the focal point of the transmitted light of the transparent-scattering type display element.
Inventors
- 👤 Yoshinori Hirai
- 👤 Yoshiharu Ooi
- 👤 Tomoki Gunjima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:36
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3141; H04N9/315
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A projection type display apparatus comprising a light source optical system having an anisotropic luminance distribution, a transparent-scattering type display element for controlling light emitted from the light source optical system and a projection optical system having an aperture stop means which projects the transmitted light, characterized in that the aperture stop means of the projection optical system is an aperture stop means having a non-circular opening which is disposed in the vicinity of the focal point of the transmitted light of the transparent-scattering type display element.
Claim 2
Dependent Claim
118 words
A projection type display apparatus comprising a light source optical system having an anisotropic luminance distribution, a transparent-scattering type display element for controlling light emitted from the light source optical system and a projection optical system having an aperture stop means which projects the transmitted light, characterized in that the aperture stop means of the projection optical system is an aperture stop means having a non-circular opening which is disposed in the vicinity of the focal point of the transmitted light of the transparent-scattering type display element, and the long axis direction in the anisotropic luminance distribution is in coincidence with the long axis direction of the opening of the aperture stop means of the projection optical system.
Claim 3
Dependent Claim
47 words
The projection type display apparatus according to Claim 1, there is the relation of: 0.2S₀ < S A < 0.7S₀ (1) where S A is the surface area of the non-circular opening and S₀ is the surface area of a circle which is circumscribed to the opening.
Claim 4
Dependent Claim
107 words
A projection type display apparatus comprising a light source optical system, a transparent-scattering type display element for controlling light emitted from the light source optical system and a projection optical system having an aperture stop means which projects the transmitted light, characterized in that the light source optical system emits a plurality of light fluxes to the transparent-scattering type display element, and the aperture stop means of the projection optical system is an aperture stop means having one or more openings other than a single circular shape which is disposed in the vicinity of the focal point of the transmitted light of the transparent-scattering type display element.
Claim 5
Dependent Claim
26 words
The projection type display apparatus according to Claim 4, wherein the openings comprises a plurality of non-circular openings which correspond to the plurality of light fluxes.
Claim 6
Dependent Claim
46 words
The projection type display apparatus according to Claim 4, there is the relation of: 0.2S₁ < S B < 0.6S₁ (2) where S B is the surface area of the openings and S₁ is the surface area of the smallest circle which includes all the openings.
Claim 7
Dependent Claim
49 words
The projection type display apparatus according to Claim 5, wherein there is the relation of: 0.2S₂ < S C < 0.7S₂ (3) where S C is the surface area of each of the openings, and S₂ is the surface area of a circle which is circumscribed to the opening.
Claim 8
Dependent Claim
60 words
The projection type display apparatus according to anyone of Claims 1, 2, 3, 5 and 7, wherein the shape of one of the openings of the aperture stop means satisfies the relation of: the width of the opening at the central portion of the long axis ≧ the width of the opening at an edge portion of the long axis.
Claim 9
Dependent Claim
121 words
The projection type display apparatus according to anyone of Claims 1 through 8, wherein said transparent-scattering type display element is a transparent-scattering type liquid crystal display element which comprises a liquid crystal and solidified matrix composite held between substrates each having an electrode, in which a nematic liquid crystal is dispersed and held in a solidified matrix; the refractive index of the liquid crystal is changed under the condition of application of a voltage in such manner that light is transmitted when the refractive index of the liquid crystal is substantially in coincidence with the refractive index of the solidified matrix in one state, and the light is scattered when the former doesn't coincide with the latter in the other state.
Claim 10
Dependent Claim
36 words
The projection type display apparatus according to Claim 9, wherein the ordinary refractive index of the nematic liquid crystal of the transparent-scattering type display element is made coincidence with the refractive index of the solidified matrix.
References Cited (Backward Citations)
EP0362776A2
Cited
US4913529A
Cited
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