Directional backlight
First Claim
1. A directional display device, comprising:
- a transmissive spatial light modulator comprising an array of pixels arranged to modulate light passing therethrough; and
at least two directional backlights, each comprising;
a waveguide having an input end, first and second, opposed guide surfaces for guiding light along the waveguide, and a reflective end facing the input end for reflecting light from the input light back through the waveguide, the first guide surface being arranged to guide light by total internal reflection, the second guide surface comprising a plurality of light extraction features oriented to reflect light guided through the waveguide after reflection from the reflective end in directions allowing exit through the first guide surface as output light, the waveguide being arranged to direct input light originating from different input positions in a lateral direction across the input end into respective optical windows in output directions distributed in the lateral direction in dependence on the input positions, the directional backlights each being arranged to supply output light through the spatial light modulator;
in respect of each directional backlight, an array of light sources at different input positions across the input end of the respective waveguide;
a control system arranged to selectively operate the light sources to direct light into said optical windows corresponding to said output directions, the control system further comprising a sensor system arranged to detect the position of an observer relative to the display device, the control system being further arranged to control the display device to display temporally multiplexed left and right images and synchronously to direct the displayed images into viewing windows in positions corresponding to left and right eyes of an observer, in dependence on the detected position of the observer.
13 Assignments
0 Petitions
Accused Products
Abstract
Disclosed is a light guiding valve apparatus including at least one transparent stepped waveguide optical valve for providing large area collimated illumination from localized light sources, and at least one further illumination source. A stepped waveguide may be a stepped structure, where the steps include extraction features hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Such controlled illumination may provide for efficient, multi-user autostereoscopic displays as well as improved 2D display functionality. Light from a separate illumination source may pass through the transparent stepped waveguide optical valve to provide at least one further additional illumination function.
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Citations
22 Claims
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1. A directional display device, comprising:
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a transmissive spatial light modulator comprising an array of pixels arranged to modulate light passing therethrough; and at least two directional backlights, each comprising; a waveguide having an input end, first and second, opposed guide surfaces for guiding light along the waveguide, and a reflective end facing the input end for reflecting light from the input light back through the waveguide, the first guide surface being arranged to guide light by total internal reflection, the second guide surface comprising a plurality of light extraction features oriented to reflect light guided through the waveguide after reflection from the reflective end in directions allowing exit through the first guide surface as output light, the waveguide being arranged to direct input light originating from different input positions in a lateral direction across the input end into respective optical windows in output directions distributed in the lateral direction in dependence on the input positions, the directional backlights each being arranged to supply output light through the spatial light modulator; in respect of each directional backlight, an array of light sources at different input positions across the input end of the respective waveguide; a control system arranged to selectively operate the light sources to direct light into said optical windows corresponding to said output directions, the control system further comprising a sensor system arranged to detect the position of an observer relative to the display device, the control system being further arranged to control the display device to display temporally multiplexed left and right images and synchronously to direct the displayed images into viewing windows in positions corresponding to left and right eyes of an observer, in dependence on the detected position of the observer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification