Waveguide comprising surface relief feature and directional backlight, directional display device, and directional display apparatus comprising said waveguide
First Claim
1. A directional backlight comprising:
- a waveguide comprising first and second, opposed guide surfaces for guiding light along the waveguide and an input surface extending between the first and second guide surfaces; and
an array of light sources arranged at different input positions along the input surface of the waveguide and arranged to input light into the waveguide, the light sources having light emitting regions that are spaced apart,the waveguide further comprising a reflective end for reflecting input light from the light sources back along the waveguide, the second guide surface being arranged to deflect the reflected input light through the first guide surface as output light, and the waveguide being arranged to image the light sources so that the output light from the light sources is directed into respective optical windows in output directions that are distributed laterally in dependence on the input positions of the light sources,wherein the waveguide further comprises at least one surface relief feature formed either on at least one of the first and second guide surfaces in a location adjacent the input surface and intermediate the light emitting regions of the light sources, and/or on the input surface intermediate the light emitting regions of the light sources, andwherein the surface relief feature is a mechanical fixing feature.
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Accused Products
Abstract
An imaging directional backlight apparatus includes a waveguide and light source array for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure in which steps may 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 defines the relative positions of system elements and ray paths. Alignment of the waveguide to mechanical and optical components may be provided by surface relief features of the waveguide arranged in regions adjacent the input surface and intermediate the light emitting regions of the light sources. Efficient, uniform operation may be achieved with low cross talk for application to autostereoscopic and privacy modes of operation.
309 Citations
22 Claims
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1. A directional backlight comprising:
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a waveguide comprising first and second, opposed guide surfaces for guiding light along the waveguide and an input surface extending between the first and second guide surfaces; and an array of light sources arranged at different input positions along the input surface of the waveguide and arranged to input light into the waveguide, the light sources having light emitting regions that are spaced apart, the waveguide further comprising a reflective end for reflecting input light from the light sources back along the waveguide, the second guide surface being arranged to deflect the reflected input light through the first guide surface as output light, and the waveguide being arranged to image the light sources so that the output light from the light sources is directed into respective optical windows in output directions that are distributed laterally in dependence on the input positions of the light sources, wherein the waveguide further comprises at least one surface relief feature formed either on at least one of the first and second guide surfaces in a location adjacent the input surface and intermediate the light emitting regions of the light sources, and/or on the input surface intermediate the light emitting regions of the light sources, and wherein the surface relief feature is a mechanical fixing feature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A directional backlight comprising:
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a waveguide comprising first and second, opposed guide surfaces for guiding light along the waveguide and an input surface extending between the first and second guide surfaces; and an array of light sources arranged at different input positions along the input surface of the waveguide and arranged to input light into the waveguide, the light sources having light emitting regions that are spaced apart, the waveguide further comprising a reflective end for reflecting input light from the light sources back along the waveguide, the second guide surface being arranged to deflect the reflected input light through the first guide surface as output light, and the waveguide being arranged to image the light sources so that the output light from the light sources is directed into respective optical windows in output directions that are distributed laterally in dependence on the input positions of the light sources, wherein the waveguide further comprises at least one surface relief feature formed either on at least one of the first and second guide surfaces in a location adjacent the input surface and intermediate the light emitting regions of the light sources, and/or on the input surface intermediate the light emitting regions of the light sources, and wherein the surface relief feature is an identification or data mark. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification