ILLUMINATION DEVICE WITH HOLOGRAPHIC LIGHT GUIDE
First Claim
1. An illumination apparatus, comprising:
- a holographic film comprising a hologram, the hologram comprising a plurality of diffractive refractive index structures,the holographic film configured to couple to a point light source disposed at an edge of the holographic film such that a light emitting face of the point light source faces the edge,wherein a density of the diffractive refractive index structures increases with increasing distance from the light source.
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Accused Products
Abstract
An illumination device includes a holographic film and a light source, such as a point light source. The point light source is positioned at an edge of the holographic film and has a light emitting face that faces the edge of the holographic film. The holographic film includes a hologram formed of diffractive refractive index structures. The density of the diffractive refractive index structures increases with increasing distance from the light source. Light is propagated from the light source through the holographic film, such as by total internal reflection. The diffractive refractive index structures turn the light, thereby causing the light to propagate out of the holographic film in a desired direction. In some embodiments, the light propagating out of the holographic film has a high uniformity across the surface of the holographic film.
130 Citations
34 Claims
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1. An illumination apparatus, comprising:
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a holographic film comprising a hologram, the hologram comprising a plurality of diffractive refractive index structures, the holographic film configured to couple to a point light source disposed at an edge of the holographic film such that a light emitting face of the point light source faces the edge, wherein a density of the diffractive refractive index structures increases with increasing distance from the light source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 20, 21, 22, 23, 24, 25)
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14. An illumination apparatus, comprising:
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a first means for generating light and directing the light through a planar body; and a second means for uniformly holographically redirecting the light out of a surface of the body. - View Dependent Claims (15, 16, 17, 18, 19)
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26. A method for illuminating a display, comprising:
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providing a point light source at an edge of a holographic film; projecting light from the point light source directly into the edge of the holographic film, the light propogating through the holographic film; and contacting the light with diffractive refractive index structures to direct the light out of a major surface of the holographic film, wherein power per area of light redirected towards picture elements of the display is substantially uniform across the major surface of the holographic film. - View Dependent Claims (27)
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28. A method for manufacturing a display device, comprising:
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providing a holographic film comprising a hologram, the hologram comprising a plurality of diffractive refractive index structures; attaching a point light source at an edge of the holographic film, a light emitting face of the point light source facing the edge; and attaching a display to the holographic film, wherein a density of the diffractive refractive index structures increases with increasing distance from the light source. - View Dependent Claims (29, 30, 31, 32, 33, 34)
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Specification