BACKLIGHT USING SURFACE-EMITTING LIGHT SOURCES
First Claim
1. A lighting apparatus for providing illumination, comprising:
- a) an array of surface-emitting light sources, wherein each surface-emitting light source directs a source illumination beam, over a beam angle θ
, toward an illumination plane;
b) an array of beam spreading optical elements corresponding with the array of surface-emitting light sources, wherein refraction of the source illumination beam by each beam spreading optical element substantially satisfies a distribution function;
dy/dθ
=ƒ
(θ
) wherein y is a radial distance along the illumination plane from the optical axis of the beam-spreading optical element, dy is an arbitrarily small increment of the radial distance, dθ
is the angular increment of the beam angle corresponding to dy, and ƒ
(θ
) is the distribution function for the angular distribution of the light source, such that each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam directed toward the illumination plane; and
, c) an array of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element reduces the angular divergence of a corresponding uniformized illumination beam, providing illumination having improved uniformity and reduced beam divergence thereby.
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Accused Products
Abstract
A lighting apparatus for providing illumination, comprising: a) an array of surface-emitting light sources, wherein each surface-emitting light source directs a source illumination beam, over a beam angle θ, toward an illumination plane; b) an array of beam spreading optical elements corresponding with the array of surface-emitting light sources, wherein refraction of the source illumination beam by each beam spreading optical element substantially satisfies a distribution function:
dy/dθ=ƒ(θ) wherein y is a radial distance along the illumination plane from the optical axis of the beam-spreading optical element, dy is an arbitrarily small increment of the radial distance, dθ is the angular increment of the beam angle corresponding to dy, and ƒ(θ) is the distribution function for the angular distribution of the light source, such that each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam directed toward the illumination plane; and, c) an array of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element reduces the angular divergence of a corresponding uniformized illumination beam, providing illumination having improved uniformity and reduced beam divergence thereby.
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Citations
16 Claims
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1. A lighting apparatus for providing illumination, comprising:
-
a) an array of surface-emitting light sources, wherein each surface-emitting light source directs a source illumination beam, over a beam angle θ
, toward an illumination plane;
b) an array of beam spreading optical elements corresponding with the array of surface-emitting light sources, wherein refraction of the source illumination beam by each beam spreading optical element substantially satisfies a distribution function;
dy/dθ
=ƒ
(θ
)wherein y is a radial distance along the illumination plane from the optical axis of the beam-spreading optical element, dy is an arbitrarily small increment of the radial distance, dθ
is the angular increment of the beam angle corresponding to dy, andƒ
(θ
) is the distribution function for the angular distribution of the light source, such that each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam directed toward the illumination plane; and
,c) an array of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element reduces the angular divergence of a corresponding uniformized illumination beam, providing illumination having improved uniformity and reduced beam divergence thereby. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
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2. A lighting apparatus for providing illumination, comprising:
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a) a plurality of surface-emitting light sources, wherein each surface-emitting light source provides a source illumination beam;
b) a plurality of beam spreading optical elements, wherein each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam;
c) a plurality of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element redirects the uniformized illumination beam toward a viewing direction to provide an illumination beam having reduced angular divergence; and
,d) a viewing angle control film, spaced apart from the beam-divergence reducing lens elements, for broadening the viewing angle of the illumination beam having reduced angular divergence. - View Dependent Claims (13)
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3. A display apparatus comprising:
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a) a plurality of surface-emitting light sources, wherein each surface-emitting light source provides a source illumination beam;
b) a plurality of beam spreading optical elements, wherein each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam;
c) a plurality of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element redirects the uniformized illumination beam toward a viewing direction to provide an illumination beam having reduced angular divergence;
d) a liquid crystal light modulator for modulating the illumination beam having reduced angular divergence to provide an image-bearing beam;
e) a viewing angle control film, spaced apart from the liquid crystal light modulator, for broadening the viewing angle of the image-bearing beam. - View Dependent Claims (4, 14)
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15. A display apparatus comprising:
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a) an array of surface-emitting light sources, wherein each surface-emitting light source directs a source illumination beam, over a beam angle θ
, toward an illumination plane;
b) an array of beam spreading optical elements corresponding with the array of surface-emitting light sources, wherein refraction of the source illumination beam by each beam spreading optical element substantially satisfies;
dy/dθ
=ƒ
(θ
)wherein y is a radial distance along the illumination plane from the optical axis, dy is an arbitrarily small increment of the radial distance, dθ
is the angular increment of the beam angle corresponding to dy, andƒ
(θ
) is a function for the angular distribution of the light source,such that each beam spreading optical element adjusts the luminous intensity of the source illumination beam from the corresponding surface-emitting light source to provide a uniformized illumination beam to the illumination plane; and
,c) an array of beam-divergence reducing lens elements, wherein each beam-divergence reducing lens element reduces the angular divergence of a corresponding uniformized illumination beam, providing an illumination having improved uniformity and reduced beam divergence thereby;
d) a liquid crystal light modulator for modulating the illumination beam having reduced beam divergence to provide an image-bearing beam; and
,e) a viewing angle control film, spaced apart from the liquid crystal light modulator, for broadening the viewing angle of the image-bearing beam. - View Dependent Claims (16)
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Specification