SYSTEMS AND METHODS FOR DESPECKLING A LASER LIGHT SOURCE
First Claim
1. A projection television comprisingan enclosure,a projection screen assembly coupled to the enclosure,an image projection engine optically coupled to the screen,a laser light source optically coupled to the image engine, anda despecking mirror system optically coupled to and interposing the laser light source and the image engine, the mirror system comprising first and second mirrors and wherein the first mirror comprises a non-flat reflective surface and is movable relative to the second mirror.
3 Assignments
0 Petitions
Accused Products
Abstract
Systems and methods that facilitate the de-speckling of a laser source in a projection televisions. In a preferred embodiment, laser light from a laser source strikes first and second mirrors on its way to a spatial light modulator and projection optics. Preferably the mirrors are incompletely flat, and preferably move or are caused to rotate. The mirrors preferably deviate from flatness by an amount of at least one or more wavelengths, and rotate at a rate different than the video frame rate and at different rates from one another to ensure that light encountering the deviation of the first mirror strikes the second mirror at a different location than on the first mirror. As the coherent light is reflected by the mirrors the path length it takes continuously changes thereby continuously changing the phase of the light striking the screen causing the bright spots in a speckle pattern to continuously disappear and reappear elsewhere on the screen.
32 Citations
18 Claims
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1. A projection television comprising
an enclosure, a projection screen assembly coupled to the enclosure, an image projection engine optically coupled to the screen, a laser light source optically coupled to the image engine, and a despecking mirror system optically coupled to and interposing the laser light source and the image engine, the mirror system comprising first and second mirrors and wherein the first mirror comprises a non-flat reflective surface and is movable relative to the second mirror.
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11. A process of projecting a video image on a screen comprising the steps of
directing laser light emanating from a laser light source toward first and second mirrors, wherein at least on of the first and second mirrors comprises a non-flat reflective surface, moving the at least one of the first and second mirrors with a non-flat reflective surface relative to the other mirror, reflecting laser light off the second mirror toward a spatial light modulator of the image engine.
Specification