Controlling light sources of a directional backlight
First Claim
1. A method of controlling an array of light sources of a directional backlight that comprises a waveguide having an input end and the array of light sources disposed at different input positions in a lateral direction across the input end of the waveguide, the light sources associated with various widths in the lateral direction, the waveguide further comprising first and second, opposed guide surfaces for guiding light along the waveguide, the waveguide being arranged to direct input light from the light sources as output light through the first guide surface into optical windows in output directions distributed in a lateral direction to a normal to the first guide surface that are dependent on the input positions;
- the method comprising selectively operating the light sources to direct light into varying optical windows, the light sources being controlled to output light with luminous fluxes, scaled inversely by the width associated with the respective light sources, that vary across the array of light sources, wherein a first light source in the array is controlled to output light with a first scaled luminous flux, the first light source being associated with a first width, and wherein a second light source in the array is controlled to output light with a second scaled luminous flux less than the first scaled luminous flux, the second light source being associated with a second width narrower than the first width.
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Accused Products
Abstract
Disclosed is an imaging directional backlight including an array of light sources, and a control system arranged to provide variable distribution of luminous fluxes, scaled inversely by the width associated with the respective light sources in the lateral direction, across the array of light sources. The luminous intensity distribution of output optical windows may be controlled to provide desirable luminance distributions in the window plane of an autostereoscopic display, a directional display operating in wide angle 2D mode, privacy mode and low power consumption mode. Image quality may be improved and power consumption reduced.
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Citations
26 Claims
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1. A method of controlling an array of light sources of a directional backlight that comprises a waveguide having an input end and the array of light sources disposed at different input positions in a lateral direction across the input end of the waveguide, the light sources associated with various widths in the lateral direction, the waveguide further comprising first and second, opposed guide surfaces for guiding light along the waveguide, the waveguide being arranged to direct input light from the light sources as output light through the first guide surface into optical windows in output directions distributed in a lateral direction to a normal to the first guide surface that are dependent on the input positions;
the method comprising selectively operating the light sources to direct light into varying optical windows, the light sources being controlled to output light with luminous fluxes, scaled inversely by the width associated with the respective light sources, that vary across the array of light sources, wherein a first light source in the array is controlled to output light with a first scaled luminous flux, the first light source being associated with a first width, and wherein a second light source in the array is controlled to output light with a second scaled luminous flux less than the first scaled luminous flux, the second light source being associated with a second width narrower than the first width. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A directional display apparatus comprising:
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a display device comprising; a waveguide having an input end; an array of light sources disposed at different input positions in a lateral direction across the input end of the waveguide, the light sources associated with various widths in the lateral direction, the waveguide further comprising first and second, opposed guide surfaces for guiding light along the waveguide, the waveguide being arranged to direct input light from the light sources as output light through the first guide surface into optical windows in output directions distributed in a lateral direction to a normal to the first guide surface that are dependent on the input positions; and a transmissive spatial light modulator arranged to receive the output light from first guide surface and to modulate it to display an image; and a control system arranged to selectively operate the light sources to direct light into varying optical windows, and to control the light sources to output light with luminous fluxes, scaled inversely by the width associated with the respective light sources, that vary across the array of light sources, wherein the control system is arranged to control a first light source in the array to output light with a first scaled luminous flux, the first light source being associated with a first width, and wherein the control system is arranged to control a second light source in the array to output light with a second scaled luminous flux less than the first scaled luminous flux, the second light source being associated with a second width narrower than the first width.
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Specification