HDR displays with individually-controllable color backlights

• US 7,800,822 B2
• Filed: 07/31/2007
• Issued: 09/21/2010
• Est. Priority Date: 03/13/2002
• Status: Expired due to Term

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Ward, Greg, Seetzen, Helge, Stuerzlinger, Wolfgang, Whitehead, Lorne A., Graham, Don
• Primary Examiner(s): MAHONEY, CHRISTOPHER E
• Application Number:
  US11/831,851
• Publication Number:
  US 20070268211A1
• Time in Patent Office: 1,148 Days
• Field of Search: 359/443, 359/449, 349/51, 349/61, 345/51, 345/55, 353 30- 31
• US Class Current: 359/443
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133613 characterized by the sequence of light sources
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3426 : the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3611 : Control of matrices with row and column drivers
• CPC Class Codes: H01J 63/06 : Lamps with luminescent screen excited by the ray or stream
• CPC Class Codes: H04N 9/3102 : using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3126 : for spatial light modulators in series
• CPC Class Codes: H04N 9/3155 : for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406
• CPC Class Codes: H04N 9/3194 : including sensor feedback
• CPC Class Codes: H04N 9/3197 : using light modulating optical valves
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light

Abstract

A display has a screen which incorporates a light modulator. The screen may be a front projection screen or a rear-projection screen. The screen is illuminated with light from a light source comprising an array of controllable light-emitters. The controllable-emitters and elements of the light modulator may be controlled to adjust the intensity of light emanating from corresponding areas on the screen. The display may provide a high dynamic range.

Claims

1. A display, comprising:

a row-by-column first array of pixel elements, each pixel element comprising a plurality of primary color light sources of a plurality of different primary colors;

a controller coupled to control each of the primary color light sources and configured to induce a spatial modulation in light emitted from the first array of pixel elements by controlling brightness of the primary color light sources; and

,

a second array comprising a plurality of individually-controllable display elements positioned to further spatially modulate the light emitted from the first array of pixel elements.

2. A display according to claim 1 wherein the display is part of a flat panel display device.

3. A display according to claim 1 wherein the display is part of a rear-projection television.

4. A display according to claim 1 wherein the display is a computer monitor.

5. A display according to claim 1 wherein the second array is controlled at least in part in response to an estimate of a light pattern projected onto the second array from the first array of pixel elements.

6. A display according to claim 1 wherein the primary color light sources comprise first light sources controllable to emit light of a first color, second light sources controllable to emit light of a second color and third light sources controllable to emit light of a third color.

7. A display according to claim 6 wherein the first color is red, the second color is green and the third color is blue.

8. A display according to claim 1 wherein the controller is configured to determine a value for each of the primary color light sources and adjust signals which control the individually-controllable display elements of the second array to reduce artefacts which result from the pixel elements of the light source being common to a plurality of the display elements of the second array.

9. A display according to claim 8 wherein the controller is configured to determine an intensity of light incident from the first array on a display element of the second array based on a known way that light from pixel elements of the first array is distributed on the second array.

10. A display according to claim 1 comprising a grid of reflective-walled channels disposed between the first array and the second array.

11. A display according to claim 10 wherein the channels are hexagonal in cross section.

12. A display according to claim 10 wherein the primary color light sources are located to direct light into the channels and primary color light sources of a plurality of different colors are disposed to emit light into each of the channels.

13. A display according to claim 12 wherein the primary color light sources comprise light-emitting diodes and the light-emitting diodes comprise a first light-emitting diode controllable to emit red light into one of the channels, a second light-emitting diode controllable to emit green light into the one of the channels and a third light emitting diode controllable to emit blue light into the one of the channels.

14. A display comprising:

a spatial light modulator comprising a two-dimensional array of controllable elements; and

a light source comprising a two-dimensional array of light-emitting elements wherein colors of light emitted from different areas of the light source are separately controllable to cause the two-dimensional array to project an image comprising colors specified by image data onto the spatial light modulator;

wherein each of the light-emitting elements illuminates multiple ones of the controllable elements, and each of the controllable elements is illuminated by multiple ones of the light-emitting elements.

15. A display according to claim 14 wherein the light-emitting elements of the light source comprise first light-emitting elements controllable to emit light of a first color and second light-emitting elements controllable to emit light of a second color and third light-emitting elements controllable to emit light of a third color.

16. A display according to claim 15 wherein the first color is red, the second color is green and the third color is blue.

17. A display according to claim 14 comprising a controller configured to determine a value for each pixel of the light source and adjust signals which control the spatial light modulator to reduce artefacts which result from the fact that each pixel of the light source is common to a plurality of pixels of the spatial light modulator.

18. A display according to claim 17 wherein the controller is configured to determine an intensity of light incident from the light source on a pixel of the spatial light modulator based on a known way that light from pixels of the light source is distributed on the spatial light modulator.

19. A display according to claim 14 comprising a grid of reflective-walled channels disposed between the light source and the spatial light modulator.

20. A display according to claim 19 wherein the channels are hexagonal in cross section.

21. A display according to claim 19 wherein the light-emitting elements are located to direct light into the channels and light-emitting elements of a plurality of different colors are disposed to emit light into each of the channels.

22. A display according to claim 21 wherein the light-emitting elements comprise light-emitting diodes and the light-emitting diodes comprise a first light-emitting diode controllable to emit red light into one of the channels, a second light-emitting diode controllable to emit green light into the one of the channels and a third light emitting diode controllable to emit blue light into the one of the channels.