Stacked backlighting system using microprisms
First Claim
1. A backlighting assembly having a particular viewing axis, comprising:
- a plurality of light pipes, each including top and bottom surfaces which define a light pipe interior, each of said plurality of light pipes being configured to be illuminated by at least one linear light source at a light entering end, each of said plurality of light pipe further being configured to direct light from said at least one linear light source into a respective light pipe interior in a predetermined way;
wherein said plurality of light pipes are together assembled so that they are configured to provide multi-level modes of one-dimensional collimated illumination output light beams having at least one characteristic propagation direction; and
a prismatic film substantially symmetric about the particular viewing axis adapted to intercept the multi-level modes of one-dimensional collimated illumination and bend the illumination toward the viewing axis.
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Accused Products
Abstract
An assembly backlighting a liquid crystal flat panel display or other such arrangement requiring backlighting is disclosed herein. The assembly includes a plurality of light pipes and is capable of a multi-mode operation as well as achieving an enhanced dimming. This assembly is composed of two or more light pipes placed in a stacked configuration. Each light pipe has a set of specially configured microprisms which, cooperating with the light pipe, provides an efficient backlighting technique with a controllable degree of collimation. The disclosed assembly is particularly useful for displays which require a very bright backlighting, a wide dimming range and which must be capable of illuminating a given active area with light of different spectra.
148 Citations
15 Claims
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1. A backlighting assembly having a particular viewing axis, comprising:
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a plurality of light pipes, each including top and bottom surfaces which define a light pipe interior, each of said plurality of light pipes being configured to be illuminated by at least one linear light source at a light entering end, each of said plurality of light pipe further being configured to direct light from said at least one linear light source into a respective light pipe interior in a predetermined way; wherein said plurality of light pipes are together assembled so that they are configured to provide multi-level modes of one-dimensional collimated illumination output light beams having at least one characteristic propagation direction; and a prismatic film substantially symmetric about the particular viewing axis adapted to intercept the multi-level modes of one-dimensional collimated illumination and bend the illumination toward the viewing axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for providing a backlighting assembly having a particular viewing axis, comprising the steps of:
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providing a plurality of light pipes, each including top and bottom surfaces which define a light pipe interior, each of said plurality of light pipes being configured to be illuminated by at least one linear light source at a light entering end, each of said plurality of light pipe further being configured to direct light from said at least one linear light source into a respective light pipe interior in a predetermined way; stacking said plurality of light pipes so that together they are configured to provide multi-level modes of one-dimensional collimated illumination output light beams having at least one characteristic propagation direction; and passing the output light beams through a prismatic film substantially symmetric about the particular viewing axis and bending the beams toward the viewing axis. - View Dependent Claims (12, 13, 14)
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15. A backlighting assembly comprising:
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first and second light pipes, each including top and bottom surfaces which define a light pipe interior; illumination means coupled to a first light entering end of the first light pipe and an opposed second light entering end of the light pipe; illumination means coupled to a light entering end of the second light pipe, wherein said plurality of light pipes are together assembled so that they are configured to provide multi-level modes of one-dimensional collimated illumination; and a prismatic film substantially symmetric about the particular viewing axis adapted to intercept the multi-level modes of one-dimensional collimated illumination and bend the illumination toward the viewing axis.
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Specification