Light scattering and guiding light source device and liquid crystal display
First Claim
1. A light scattering and guiding light source device comprising:
- a light source element; and
a light scattering guide having a wedge shape, a light incident surface for receiving light from the light source element, a light exit surface and an inclined surface, the light incident surface being at a thick end of the wedge shape such that the thickness of the light scattering guide decreases with increasing distance from the light incident surface,the light exit surface and the inclined surface extending from the light incident surface with the inclined surface being inclined with respect to the light exit surface,the light scattering guide having a uniform scattering power greater than zero inside to provide three dimensional scattering to light travelling through the light scattering guide such that light received from the light source element at the light incident surface is emitted uniformly from the light exit surface.
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Accused Products
Abstract
A light scattering and guiding light source device which is capable of providing a uniform illumination light, simple structure and low cost. A wedge-shaped light scattering guide has an incident surface for introducing light rays from a fluorescent lamp. The directions of the rays are changed by scattering. The rays propagate through the body while reflected repeatedly. Parts of the rays go outwards at plural reflective points. The angle of reflection increases successively, thus increasing the possibility that the light exits from the exit surface. This effect cancels another effect that portions close to the light source shines strongly. Both effects are balanced to make uniform the brightness over the exit surface. Reflective sheets are disposed along the inclined surface and around the fluorescent lamp to keep the brightness high. A prismatic exit direction modifier giving on the light exit surface is employed to modify the light exit direction characteristic. The light source device is mounted on a liquid crystal display as a backlight source to provide an improved display quality.
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Citations
8 Claims
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1. A light scattering and guiding light source device comprising:
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a light source element; and a light scattering guide having a wedge shape, a light incident surface for receiving light from the light source element, a light exit surface and an inclined surface, the light incident surface being at a thick end of the wedge shape such that the thickness of the light scattering guide decreases with increasing distance from the light incident surface, the light exit surface and the inclined surface extending from the light incident surface with the inclined surface being inclined with respect to the light exit surface, the light scattering guide having a uniform scattering power greater than zero inside to provide three dimensional scattering to light travelling through the light scattering guide such that light received from the light source element at the light incident surface is emitted uniformly from the light exit surface. - View Dependent Claims (2, 3, 4)
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5. A liquid crystal display device, comprising:
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a light source element; a light scattering guide having a wedge shape, a light incident surface for receiving light from the light source element, a light exit surface and an inclined surface, the light incident surface being at a thick end of the wedge shape such that the thickness of the light scattering guide decreases with increasing distance from the light incident surface, the light exit surface and the inclined surface extending from the light incident surface with the inclined surface being inclined with respect to the light exit surface, the light scattering guide having a uniform scattering power greater than zero inside to provide three dimensional scattering to light travelling through the light scattering guide such that light received from the light source element at the light incident surface is emitted uniformly from the light exit surface; and a liquid crystal display provided adjacent to the light exit surface of the light scattering guide to receive backlighting from the light emitted from the light exit surface. - View Dependent Claims (6, 7, 8)
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Specification