Image display

Patent metadata

Field	Value
Publication number	US-10416480-B2
Application number	US-201615001068-A
Country	US
Kind code	B2
Filing date	Jan 19, 2016
Priority date	Mar 13, 2002
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

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.

First claim

What is claimed is:

1. A display comprising:
a light source comprising an array of light-emitting elements each having a controllable light output;
a spatial light modulator illuminated by-the light source; and
a grid of reflective-walled channels disposed between the light source and the spatial light modulator;
wherein light from the light source passes through the channels to illuminate the spatial light modulator.

2. A display according to claim 1 wherein the array of light-emitting elements comprises a rectangular array.

3. A display according to claim 1 wherein the grid comprises a honeycomb structure.

4. A display according to claim 3 wherein the honeycomb structure comprises an aluminium honeycomb material.

5. A display according to claim 3 wherein the light-emitting elements are arranged in a hexagonal array.

6. A display according to claim 1 wherein reflective walls of the channels provide an interface at which light is totally internally reflected.

7. A display according to claim 1 wherein the grid is spaced away from the spatial light modulator.

8. A display according to claim 1 wherein the channels have a length L which satisfies

L
=

R

tan
⁡

(

θ

1
2

)

wherein R is the half-width of the channel and θ 1/2 is the angle at which light from one of the light-emitting elements has an intensity equal to one half of the intensity of illumination provided by the light-emitting element in a forward direction on-axis of the light-emitting element.

9. A display according to claim 1 wherein the light-emitting elements emit white light.

10. A display according to claim 1 wherein the light-emitting elements comprise light-emitting diodes.

11. A display according to claim 10 wherein the grid is provided by columns formed integrally with material that encapsulates the LEDs.

12. A display according to claim 1 wherein one of the channels is provided for each of the light-emitting elements.

13. A display according to claim 1 wherein, for each of the channels, the light source comprises a plurality of LEDs.

14. A display according to claim 13 wherein the LEDs for each of the channels emit light of a plurality of different colours.

15. A display according to claim 13 wherein LEDs operative to emit a mix of red, green, and blue light correspond to each of the channels.

16. A display according to claim 1 wherein the grid functions to improve uniformity of illumination of that part of the spatial light modulator illuminated by each of the light-emitting elements.

17. A display according to claim 1 wherein the channels are hexagonal in cross-section.

18. A display according to claim 1 wherein the channels are triangular or square in cross-section.

19. A display according to claim 1 comprising a controller connected to control the light-emitting elements of the light source to provide a low-resolution version of an image to be displayed on the spatial light modulator.

20. A display according to claim 1 wherein the spatial light modulator is a high-resolution colour light modulator.

21. A display according to claim 1 wherein the display has a thickness of 10 cm or less.

22. A display according to claim 1 wherein the reflective-walled channels comprise columns of light-transmitting material having walls at which light is internally reflected.

23. A display according to claim 22 wherein the columns are integral with the light-emitting elements.

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Whitehead Lorne A
• Ward Gregory John
• Stuerzlinger Wolfgang
• Seetzen Helge
• Graham Don

Classifications

• H05B45/20

  Controlling the colour of the light · CPC title

• G09G3/34

  by control of light from an independent source · CPC title

• G09G2320/066

  for control of contrast · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G3/32

  semiconductive, e.g. using light-emitting diodes [LED] · CPC title