Backlighted liquid crystal display using light passage member for more nearly uniform illumination
First Claim
1. A liquid crystal display device comprising:
- a liquid crystal display panel;
light source means for illuminating said liquid crystal display panel;
a light passage member of one of a transparent and a translucent material, said light passage member being disposed between said liquid crystal panel and said light source means; and
a light relecting member substantially surounding said light source means and said light passage member, said light reflecting member having an opening facing said liquid crystal display panel to expose a surface portion of said light passage member, said light passage member and light reflecting member being adapted to provide light more uniformly across said display panel at varying distances from said light source means with the length of a light path between said light source and said exposed surface portion being substantially uniform throughout said light passage member by reducing the distance between the reflecting member and the display panel as the distance from the light source means increases;
wherein the reflecting member is one of a metal plate, a metal film and a lamination sheet of aluminum and plastic adhered to surface portions of said light passage member other than said opening.
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Accused Products
Abstract
A liquid crystal display panel having a backlight for providing high brightness, uniformity of illumination intensity, small thickness, high efficiency and which can be manufactured at a low cost. The display device includes a liquid crystal display panel, a light source for illuminating the liquid crystal panel, a light passage member which can be formed of either transparent or translucent material disposed between the liquid crystal panel and the light source. The light source inlet side of the light passage member is formed with a recess so that the thickness is reduced at the region opposed to the brightest region of the light source. A light reflecting member substantially surrounds the light source and the light passage member is formed with an opening facing the liquid crystal panel to expose a surface portion of the light passage member. The light source can either be incandescent light bulb or a cold-cathode discharge tube. In the latter case, a thermistor is coupled in series with the tube to stabilize its temperature and hence stabilize the illumination intensity against changes in ambient temperature.
57 Citations
28 Claims
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1. A liquid crystal display device comprising:
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a liquid crystal display panel; light source means for illuminating said liquid crystal display panel; a light passage member of one of a transparent and a translucent material, said light passage member being disposed between said liquid crystal panel and said light source means; and a light relecting member substantially surounding said light source means and said light passage member, said light reflecting member having an opening facing said liquid crystal display panel to expose a surface portion of said light passage member, said light passage member and light reflecting member being adapted to provide light more uniformly across said display panel at varying distances from said light source means with the length of a light path between said light source and said exposed surface portion being substantially uniform throughout said light passage member by reducing the distance between the reflecting member and the display panel as the distance from the light source means increases; wherein the reflecting member is one of a metal plate, a metal film and a lamination sheet of aluminum and plastic adhered to surface portions of said light passage member other than said opening. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A liquid crystal display device comprising:
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a liquid crystal display panel; light source means for illuminating said liquid crystal display panel; a light passage member disposed between said liquid crystal display panel and said light source means; wherein said light source means includes a cold-cathode discharge tube and further includes a wavelength selection filter disposed between said liquid crystal display panel and said light source means. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification