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.
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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