Uniform illumination system
First Claim
1. An image display system, comprising:
- means for generating image information including a spatial light modulator; and
a light source system for directly illuminating said spatial light modulator comprised of;
a one-dimensional array of substantially parallel emitting channels located behind said spatial light modulator, said array having an output area and shape arranged to at least match the aperture size of said spatial light modulator, each channel of said array having an emitting width W defined by the projected length of emitting material enclosed by said channel, as measured perpendicular to the axis of said channel and as viewed from above said array, adjacent of transparent regions of equal intra-channel separation W′
, with the separation W′
being substantially less than the width W and equal to the shortest distance between said emitting material of any one said channel and said emitting material of any adjacent said channel;
a first light directing layer including a parallel array of at least one of transparent dielectric micro prisms and aspheric semi-cylinders on a transparent substrate, said substrate arranged parallel to an output plane of said emitting channels and between the output plane of said emitting channels and the input side of said spatial light modulator, separated from said emitting channel output plane by an optical distance G1, with the optical distance G1 being less than the width W;
a second light directing layer disposed between said first light directing layer and said spatial light modulator arranged parallel to and above said first light directing layer by an air-gap of thickness S1, with the thickness S1 being substantially less than W+W′
, said second light directing layer including one or more of a holographic diffuser sheet, a bulk diffuser sheet, a surface diffuser sheet, a lenticular lens diffuser sheet, and a reflective polarizer film; and
a light reflecting layer located behind a rear side of said emitting channels a distance Y from a rear side emitting plane, the distance Y being substantially less than the separation W′
, said light reflecting layer including at least one of a white diffuse reflecting material, a specular reflecting material, a prismatic reflecting material, a structured transparent reflecting material, a bulk diffuser, a holographic diffuser, and a flat substantially transparent substrate.
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Accused Products
Abstract
A compact and efficient optical illumination system featuring planar multi-layered LED light source arrays concentrating their polarized or un-polarized output within a limited angular range. The optical system manipulates light emitted by a planar light emitters such as electrically-interconnected LED chips. Each light emitting region in the array is surrounded by reflecting sidewalls whose output is processed by elevated prismatic films, polarization converting films, or both. The optical interaction between light emitters, reflecting sidewalls, and the elevated prismatic films create overlapping virtual images between emitting regions that contribute to the greater optical uniformity. Practical illumination applications of such uniform light source arrays include compact LCD or DMD video image projectors, as well as general lighting, automotive lighting, and LCD backlighting.
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Citations
71 Claims
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1. An image display system, comprising:
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means for generating image information including a spatial light modulator; and a light source system for directly illuminating said spatial light modulator comprised of; a one-dimensional array of substantially parallel emitting channels located behind said spatial light modulator, said array having an output area and shape arranged to at least match the aperture size of said spatial light modulator, each channel of said array having an emitting width W defined by the projected length of emitting material enclosed by said channel, as measured perpendicular to the axis of said channel and as viewed from above said array, adjacent of transparent regions of equal intra-channel separation W′
, with the separation W′
being substantially less than the width W and equal to the shortest distance between said emitting material of any one said channel and said emitting material of any adjacent said channel;a first light directing layer including a parallel array of at least one of transparent dielectric micro prisms and aspheric semi-cylinders on a transparent substrate, said substrate arranged parallel to an output plane of said emitting channels and between the output plane of said emitting channels and the input side of said spatial light modulator, separated from said emitting channel output plane by an optical distance G1, with the optical distance G1 being less than the width W; a second light directing layer disposed between said first light directing layer and said spatial light modulator arranged parallel to and above said first light directing layer by an air-gap of thickness S1, with the thickness S1 being substantially less than W+W′
, said second light directing layer including one or more of a holographic diffuser sheet, a bulk diffuser sheet, a surface diffuser sheet, a lenticular lens diffuser sheet, and a reflective polarizer film; anda light reflecting layer located behind a rear side of said emitting channels a distance Y from a rear side emitting plane, the distance Y being substantially less than the separation W′
, said light reflecting layer including at least one of a white diffuse reflecting material, a specular reflecting material, a prismatic reflecting material, a structured transparent reflecting material, a bulk diffuser, a holographic diffuser, and a flat substantially transparent substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An illuminating system comprising:
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a planar array composed of two or more light emitting diode chips, the same substantially identically sized with largest lateral dimension LL, each said light emitting diode chip separated from neighboring chips by a substantially equal center-to-center spacing W+W′
being less than or equal to a distance 2 LL;a flat mounting plate disposed behind said array of said light emitting diode chips, providing support and electrical interconnection means for said light emitting diode chips; a first light redirecting layer of thickness H+G1′
, disposed above said flat mounting plate, comprising an array of substantially same-sized tapered holes, sidewalls of each said hole slanting outwards from a first opening having first edges of a length greater than or equal to LL, to a second opening having second edges of length W+W′
, said sidewalls being smooth and reflective, said second openings having said second edges substantially contiguous with one another; and
with each said first opening containing at least one of said light emitting diode chips in said planar array;a second light redirecting layer comprising a transparent dielectric medium whose top surface contains a regular array of substantially contiguous v-shaped grooves with each groove having a smooth sidewall, substantially equal groove angle, and substantially equal groove depth, said second light redirecting layer disposed a first elevation G1′
+H above said array of said light emitting diode chips; anda third light redirecting layer disposed above said second light redirecting layer, including at least one of a light scattering diffuser, a quarter-wave phase retardation film, and a polarizer for at least one of absorbing and reflecting light of a first polarization state and transmitting light of a second polarization state orthogonal to said first polarization state. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. An image projection system comprising:
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a projection lens having an acceptance angle +/−
ω
;a color mixing system having a first, second and third input faces and a single output face, with first second and third light beams of first second and third emitting colors respectively provided to said first, second and third input faces respectively, and then combined as a single output beam of light passing through said single output face, said output beam of light formed as a superposition of said first, second and third input beams; first, second and third LCD micro-displays having respective first, second and third image apertures of equal rectangular horizontal and vertical edge dimensions H and V; first, second and third angle transforming sub-systems, each of the sub-systems including at least one of a first, second and third positive lens, a first, second and third concave mirror, a first, second and third polarizing beam splitter, a first, second and third quarter-wave phase retardation layer; first, second and third planar light source arrays, each said array including an array of equally spaced light emitting diode chips respectively of first, second and third emitting;
color, a flat interconnection plate, an array of hollow bins having tapered specularly-reflecting sidewalls, first and second light redirecting layers, a quarter-wave phase retardation film and a polarization-selective reflector, with each said hollow bin disposed about each of said light emitting diode chips, said first and second light redirecting layers disposed above said array of hollow bins; andsaid projection lens focused on each said rectangular image aperture, said first, second and third angle-transforming sub-systems collecting input illumination from said first, second, and third planar light source arrays, respectively, each over an equal input angular range +/−
β
, said first, second and third angle-transforming sub-systems functioning to convert respectively said first, second and third input illumination each from angle +/−
β
to first, second and third light beams of first, second and third output illumination angle +/−
ω
, while simultaneously redirecting said first, second and third light beams respectively to said first, second and third image apertures of said first, second and third LCD micro-displays. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55)
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56. An illumination system comprising,
a color mixing system having a first, second and third input faces and a single output face, with the mixing system functioning to provide first, second and third light beams of first, second and third emitting colors, respectively, provided to said first, second and third input faces, respectively, and then combined as a single output beam of light passing through said single output face, said output beam formed as a superposition of said first, second and third input beams; -
first, second and third planar light source arrays, each including an array of equally spaced light emitting diode chips respectively of first, second and third emitting color, a flat interconnection plate, an array of hollow bins having tapered specularly-reflecting sidewalls with each said hollow bin disposed about each said light emitting diode, a first and second light redirecting layers, said first and second light redirecting layers disposed above said array of hollow bins; and said first, second and third planar light source arrays each located at said first, second, and third input faces of said color mixing system. - View Dependent Claims (57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71)
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Specification