Segmented imaging directional backlights
First Claim
1. A directional display device comprising:
- plural waveguides, wherein each waveguide comprises;
an input end arranged to receive input light;
a reflective end;
first and second, opposed guide surfaces extending between the input end and the reflective end for guiding light along the waveguide from the input end to the reflective end for reflection of the input light back along the waveguide as reflected input light; and
sides extending between the opposed guide surfaces and between the input end and the reflective end,wherein the first guide surface is arranged to guide light by total internal reflection, and the second guide surface comprises light extraction features and intermediate regions between the light extraction features, the light extraction features being arranged to deflect the reflected input light in directions allowing exit through the first guide surface as output light, the intermediate regions being arranged to direct light along the waveguide without extraction; and
in respect of each of the plural waveguides, an array of light sources disposed at different input positions along the input side of the waveguide and arranged to input input light into the waveguide,a transmissive spatial light modulator, the plural waveguides being arranged in a tiled array alongside each other with the first guide surfaces of the plural waveguides facing the spatial light modulator and the first ends of the plural waveguides on the same side of the array of plural waveguides, the spatial light modulator being arranged to receive and modulate the output light from each of the plural waveguides;
the plural waveguides including a first waveguide and a second waveguide that are adjacent, wherein the light extraction features of the second waveguide are shaped differently from the light extraction features of the first waveguide, and, along the sides of the first and second waveguides that are adjacent, the ends of the light extraction features of the second waveguide are aligned angularly with respect to the lateral direction with the ends of the light extraction features of the first waveguide.
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Accused Products
Abstract
An imaging directional backlight apparatus includes a waveguide and a light source array, providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, and the steps may further include extraction features optically hidden to guided light, propagating in a forward direction. Returning light propagating in a backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources and define the relative positions of system elements and ray paths. The imaging directional backlight apparatus further includes multiple waveguides with light extraction features arranged to provide uniform output luminance at the seam between the waveguides.
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Citations
45 Claims
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1. A directional display device comprising:
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plural waveguides, wherein each waveguide comprises; an input end arranged to receive input light; a reflective end; first and second, opposed guide surfaces extending between the input end and the reflective end for guiding light along the waveguide from the input end to the reflective end for reflection of the input light back along the waveguide as reflected input light; and sides extending between the opposed guide surfaces and between the input end and the reflective end, wherein the first guide surface is arranged to guide light by total internal reflection, and the second guide surface comprises light extraction features and intermediate regions between the light extraction features, the light extraction features being arranged to deflect the reflected input light in directions allowing exit through the first guide surface as output light, the intermediate regions being arranged to direct light along the waveguide without extraction; and in respect of each of the plural waveguides, an array of light sources disposed at different input positions along the input side of the waveguide and arranged to input input light into the waveguide, a transmissive spatial light modulator, the plural waveguides being arranged in a tiled array alongside each other with the first guide surfaces of the plural waveguides facing the spatial light modulator and the first ends of the plural waveguides on the same side of the array of plural waveguides, the spatial light modulator being arranged to receive and modulate the output light from each of the plural waveguides; the plural waveguides including a first waveguide and a second waveguide that are adjacent, wherein the light extraction features of the second waveguide are shaped differently from the light extraction features of the first waveguide, and, along the sides of the first and second waveguides that are adjacent, the ends of the light extraction features of the second waveguide are aligned angularly with respect to the lateral direction with the ends of the light extraction features of the first waveguide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A directional display device comprising:
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plural waveguides, wherein each waveguide comprises; an input end arranged to receive input light; a reflective end; first and second, opposed guide surfaces extending between the input end and the reflective end for guiding light along the waveguide from the input end to the reflective end for reflection of the input light back along the waveguide as reflected input light; and sides extending between the opposed guide surfaces and between the input end and the reflective end, wherein the first guide surface is arranged to guide light by total internal reflection, and the second guide surface comprises light extraction features and intermediate regions between the light extraction features, the light extraction features being arranged to deflect the reflected input light in directions allowing exit through the first guide surface as output light, the intermediate regions being arranged to direct light along the waveguide without extraction; and in respect of each of the plural waveguides, an array of light sources disposed at different input positions along the input side of the waveguide and arranged to input input light into the waveguide, a transmissive spatial light modulator, the plural waveguides being arranged in a tiled array alongside each other with the first guide surfaces of the plural waveguides facing the spatial light modulator and the first ends of the plural waveguides on the same side of the array of plural waveguides, the spatial light modulator being arranged to receive and modulate the output light from each of the plural waveguides; the plural waveguides including a first waveguide and a second waveguide that are adjacent, wherein in a lateral direction between the sides of the first waveguide, the light extraction features of the first waveguide are curved and have positive optical power with respect to the reflected input light, and in a lateral direction between the sides of the second waveguide, the light extraction features of the second waveguide are straight and have zero optical power with respect to the reflected input light, or are curved and have negative optical power with respect to the reflected input light. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A directional display device comprising:
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plural waveguides, wherein each waveguide comprises; an input end arranged to receive input light; a reflective end; first and second, opposed guide surfaces extending between the input end and the reflective end for guiding light along the waveguide from the input end to the reflective end for reflection of the input light back along the waveguide as reflected input light; and sides extending between the opposed guide surfaces and between the input end and the reflective end, wherein the reflective end has positive optical power in the lateral direction between the sides of the waveguide, and the first guide surface is arranged to guide light by total internal reflection, and the second guide surface comprises light extraction features and intermediate regions between the light extraction features, the light extraction features being arranged to deflect the reflected input light in directions allowing exit through the first guide surface as output light, the intermediate regions being arranged to direct light along the waveguide without extraction; and in respect of each of the plural waveguides, an array of light sources disposed at different input positions along the input side of the waveguide and arranged to input input light into the waveguide, a transmissive spatial light modulator, the plural waveguides being arranged in a tiled array alongside each other with the first guide surfaces of the plural waveguides facing the spatial light modulator and the first ends of the plural waveguides on the same side of the array of plural waveguides, the spatial light modulator being arranged to receive and modulate the output light from each of the plural waveguides; the plural waveguides including a first waveguide and a second waveguide that are adjacent, wherein the light extraction features of the second waveguide are shaped differently from the light extraction features of the first waveguide. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
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Specification