EP0807849A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Light-diffusing sheet, and projection-type screen and liquid crystal display unit both provided with said light-diffusing sheet
Assignee: Kuraray Co Ltd
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Filing: 1997-05-09
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Granted: —
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Expires: 2017-05-09
Abstract
Abstract A light-diffusing sheet of the type having a clear film ( 1 ) and two light diffusing layers ( 2 , 3 ) formed consecutively thereon, characterized in that the first light-diffusing layer ( 2 ) is a film of clear resin incorporated with a light-diffusing material, and the second light-diffusing layer ( 3 ) is a film of clear resin having a corrugated surface structure formed thereon. It can be used for the rear-projection screen without the occurrence of moiré pattern. It can also be used for the front-projection screen which permits the viewing angles to be established in the horizontal and vertical directions independently. Furthermore, it can be used for the liquid crystal display unit to increase its viewing angle without decreasing contrast.
Inventors
- 👤 Katsuya Fujisawa
- 👤 Rikuji Wantanabe
- 👤 Ikuo Ohnishi
- 👤 Katsuhiko Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 09:11
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02B; G02B5/00; G02B5/02; G02B5/0205; G02B5/021; G02B5/0221; G02B5/0236; G02B5/0242; G02B5/0273; G02B5/0278; G02F1/133504; G03; G03B; G03B21/00; G03B21/54; G03B21/56; G03B21/60
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
53 words
A light-diffusing sheet of the type having a clear film and two light-diffusing layers formed consecutively thereon, characterized in that the first light-diffusing layer is a film of clear resin incorporated with a light-diffusing material, and the second light-diffusing layer is a film of clear resin having a corrugated surface structure formed thereon.
Claim 2
Dependent Claim
111 words
The light-diffusing sheet as defined in Claim 1, which meets the conditions specified by the equation below. 10 µm ≤ t ≤ 500 µm 0.01 ≤ Δn ≤ 0.12 3 wt% ≤ c 4 µm ≤ d ≤ 30 µm where, t denotes the thickness of the first light-diffusing layer; Δn denotes the difference between the refractive index of the light-diffusing material in the first light-diffusing layer and the refractive index of the clear resin of the first light-diffusing layer; c denotes the concentration (by weight) of the light-diffusing material in the first light-diffusing layer; and d denotes the average particle diameter of the light-diffusing material in the first light-diffusing layer.
Claim 3
Dependent Claim
42 words
The light-diffusing sheet as defined in Claim 1 or 2, which is characterized in that the corrugated surface structure meets the conditions specified by the equation below. 1 µm ≤ p ≤ 600 µm where, p denotes the pitch of the corrugation.
Claim 4
Dependent Claim
23 words
The light-diffusing sheet as defined in any of the preceding claims, which is characterized in that the clear film is a polarizing film.
Claim 5
Dependent Claim
28 words
A rear-projection screen which comprises the light-diffusing sheet defined in any of the preceding claims and a transparent plate bonded together, with the corrugated surface structure facing outside.
Claim 6
Dependent Claim
25 words
A rear-projection screen which comprises the light-diffusing sheet defined in Claim 4 and a transparent plate bonded together, with the corrugated surface structure facing outside.
Claim 7
Dependent Claim
28 words
A front-projection screen which comprises the light-diffusing sheet defined in any of the preceding claims and a transparent plate bonded together, with the corrugated surface structure facing outside.
Claim 8
Dependent Claim
53 words
A liquid crystal display unit which comprises a light source, a first polarizing plate, a liquid crystal panel, a second polarizing plate, and the light-diffusing sheet defined in any of the preceding claims, which are arranged in the order metnioned, with the light-diffusing sheet positioned such that the corrugated surface structure faces outside.
Claim 9
Dependent Claim
46 words
A liquid crystal display unit which comprises a light source, a polarizing plate, a liquid crystal panel, and the light- diffusing sheet defined in Claim 4, which are arranged in the order mentioned, with the light-diffusing sheet positioned such that the corrugated surface structure faces outside.
References Cited (Backward Citations)
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