Flat-panel optical projection apparatus with reduced distortion
First Claim
1. A light guide comprising:
- an input slab; and
an output waveguide arranged to receive light from an output end of the input slab, and to emit the light through an output face, such that a thickness of the input slab is varied in a transverse direction that is transverse to a central axis of light travel so that light travelling from an input end of the input slab toward the output end bounces a same number of times in the input slab, regardless of fan-out from the central axis.
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Accused Products
Abstract
A light guide of the tapered-waveguide type includes an input slab for expanding a projected image between an input end and an output end; and a tapered output slab arranged to receive rays from the said output end of the input slab, and to emit them at a point on its face that corresponds to the angle at which the ray is received. The taper is calculated so that all rays injected into the input end undergo the same number of reflections before leaving the output face. The thickness of the input slab light guide is greater in the transverse direction away from the center line, so that light travelling at the critical angle from the input face of the slab waveguide towards the output waveguide bounces the same number of times in the input slab, regardless of its fan-out angle, in order to further reduce image distortion.
105 Citations
20 Claims
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1. A light guide comprising:
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an input slab; and an output waveguide arranged to receive light from an output end of the input slab, and to emit the light through an output face, such that a thickness of the input slab is varied in a transverse direction that is transverse to a central axis of light travel so that light travelling from an input end of the input slab toward the output end bounces a same number of times in the input slab, regardless of fan-out from the central axis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A light guide comprising:
a light guide slab that allows light rays travelling from an input end toward an output end to fan out, wherein a thickness of the light guide slab is varied in a transverse direction perpendicular to a central axis of ray travel so that a light ray that fans out while travelling at an out-of-plane angle from the input end of the light guide slab toward the output end bounces a same number of times in the light guide slab as a light ray travelling along the central axis at a same out-of-plane angle. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A light guide comprising:
a light guide slab that allows light rays travelling from an input end toward an output end to fan out toward lateral edges of the light guide slab, wherein a thickness of the light guide slab is varied from the lateral edges to a centre-line of the light guide slab so that the light rays travelling at an out-of-plane angle from the input end of the light guide slab toward the output end reflect a same number of times in the light guide slab regardless of a fan-out angle of the light rays toward the lateral edges of the light guide slab. - View Dependent Claims (16, 17, 18, 19, 20)
Specification