Backlight device and liquid crystal display apparatus
First Claim
1. A diffusion member which diffuses light rays from a plurality of light sources, and which has a transmittance for all light rays of 50% or more and a cloud value of 90 to 99%, comprising:
- a plurality of light dimming portions having a reflecting property, a light shielding property and diffusing property on a light incident surface or a light radiating surface of the diffusion member;
wherein,said light dimming portions are generated such that a size of the light dimming portions varies so as to increase light volume to be shielded at a position close to a position directly above of said light sources and to decrease the light volume to be shielded at a position remote from said light sources.
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Accused Products
Abstract
A light dimming dot pattern is provided for an LCD in which the diameter of dots is changed in a range from approximately 0.16 mm to approximately 0.65 mm depending on the distance of the dots from a fluorescent tube (13) in such a manner that the volume of the shielded light is increased and decreased at a location close to a position overlying the fluorescent tube (13) and at a location remote from the fluorescent tube (13), respectively. In this manner, a light dimming dot pattern with a transmittance for all light rays of approximately 62% (roughly in the vicinity of 62%), higher than the transmittance for all light rays in the conventional technique not higher than 50%, is produced. Consequently, the light of uniform high luminance may be produced without raising the luminance of the fluorescent tube (13), and hence an LCD of high luminance may be realized.
131 Citations
11 Claims
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1. A diffusion member which diffuses light rays from a plurality of light sources, and which has a transmittance for all light rays of 50% or more and a cloud value of 90 to 99%, comprising:
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a plurality of light dimming portions having a reflecting property, a light shielding property and diffusing property on a light incident surface or a light radiating surface of the diffusion member; wherein, said light dimming portions are generated such that a size of the light dimming portions varies so as to increase light volume to be shielded at a position close to a position directly above of said light sources and to decrease the light volume to be shielded at a position remote from said light sources. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A backlight device comprising:
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a plurality of light sources; a first diffusion member which diffuses light rays radiated from said light sources; a second diffusion member which diffuses light rays radiated from said first diffusion member, the second diffusion member having a transmittance for all light rays of 50% or more and a cloud value of 90 to 99%; and a plurality of light dimming portions having a reflecting property, a light shielding property and diffusing property on a light incident surface or a light radiating surface of the second diffusion member, wherein, said light dimming portions are generated such that a size of the light dimming portions varies so as to increase light volume to be shielded at a position close to a position directly above of said light sources and to decrease the light volume to be shielded at a position remoter from said light sources.
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11. A liquid crystal display apparatus comprising:
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a light transmitting liquid crystal display panel; and a backlight device for illuminating the liquid crystal display panel from a back side thereof, said backlight device including (a) a plurality of light sources, (b) a first diffusion member which diffuses light rays from said light sources, (c) a second diffusion member which diffuses light rays radiated from said first diffusion member, the second diffusion member having a transmittance for all light rays of 50% or more and a cloud value of 90 to 99%, and (d) a plurality of light dimming portions having a reflecting property, a light shielding property and diffusing property on a light incident surface or a light radiating surface of the second diffusion member, wherein, said light dimming portions are generated such that a size of the light dimming portions varies so as to increase light volume to be shielded at a position close to a position directly above of said light sources and to decrease the light volume to be shielded at a position remoter from said light sources.
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Specification