Multibeam element-based backlight and display using same

Patent metadata

Field	Value
Publication number	US-10838134-B2
Application number	US-201816010443-A
Country	US
Kind code	B2
Filing date	Jun 16, 2018
Priority date	Jan 30, 2016
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A multiview backlight and a multiview display employ multibeam elements configured to provide a plurality of light beams having different principal angular directions corresponding to different view directions of the multiview display. The display includes multiview pixels that include sub-pixels. A size of the multibeam element is comparable to a size of a sub-pixel in a multiview pixel of the multiview display.

First claim

What is claimed is:

1. A multiview backlight comprising:
a light guide configured to guide light in a propagation direction along a length of the light guide; and
a plurality of multibeam elements spaced apart from one another along the light guide length, a multibeam element of the plurality of multibeam elements being configured to couple out from the light guide a portion of the guided light as a plurality of coupled-out light beams having different principal angular directions corresponding to respective different view directions of a multiview display comprising multiview pixels,
wherein a size of the multibeam element is comparable to a size of a sub-pixel in a multiview pixel of the multiview display, and
wherein an inter-element distance between a pair of multibeam elements of the plurality of multibeam elements is equal to an inter-pixel distance between a corresponding pair of multiview pixels.

2. The multiview backlight of claim 1 , wherein a relationship between the multibeam elements of the plurality of multibeam elements and corresponding multiview pixels of the multiview display is a one-to-one relationship.

3. The multiview backlight of claim 1 , wherein the size of the multibeam element is between fifty percent and two hundred percent of the sub-pixel size.

4. The multiview backlight of claim 1 , wherein a shape of the multibeam element is analogous to a shape of the multiview pixel.

5. The multiview backlight of claim 1 , wherein the multibeam element comprises a diffraction grating configured to diffractively couple out the portion of the guided light as the plurality of coupled-out light beams.

6. The multiview backlight of claim 1 , wherein the multibeam element comprises one or both of a micro-reflective element and a micro-refractive element, the micro-reflective element being configured to reflectively couple out a portion of the guided light, the micro-refractive element being configured to refractively couple out a portion of the guided light.

7. The multiview backlight of claim 1 , wherein the multibeam element is located one of at a first surface and at a second surface of the light guide, the multibeam element being configured to couple out the guided light portion through the first surface.

8. The multiview backlight of claim 1 , further comprising a light source optically coupled to an input of the light guide, the light source being configured to provide the guided light one or both of having a non-zero propagation angle and being collimated according to a predetermined collimation factor.

9. The multiview backlight of claim 1 , wherein a combination of the light guide and the plurality of multibeam elements is configured to be substantially optically transparent through the light guide in a direction orthogonal to the propagation direction of the guided light.

10. A multiview display comprising the multiview backlight of claim 1 , the multiview display further comprising an array of light valves configured to modulate light beams of the coupled-out light beam plurality, a light valve of the array corresponding to the sub-pixel, a set of light valves of the array corresponding to the multiview pixel of the multiview display.

11. A multiview display comprising:
an array of multiview pixels configured to provide a plurality of different views of the multiview display, a multiview pixel comprising a plurality of sub-pixels configured to modulate a plurality of light beams; and
an array of multibeam elements, each multibeam element being configured to provide the plurality of light beams to a corresponding multiview pixel, light beams of the plurality of light beams having different principal angular directions from one another corresponding to different view directions of the different views,
wherein a size of a multibeam element of the multibeam element array is comparable to a size of a sub-pixel of the sub-pixel plurality, an inter-element distance between adjacent multibeam elements of the multibeam element array corresponds to an inter-pixel distance between adjacent multiview pixels of the multiview pixel array, and
wherein a constant inter-element distance between the multibeam elements is less than or equal to a constant inter-pixel distance between the multiview pixels.

12. The multiview display of claim 11 , further comprising a light guide configured to guide light, wherein the multibeam element of the multibeam element array is configured to couple out from the light guide a portion of the guided light as the plurality of light beams provided to the corresponding multiview pixel.

13. The multiview display of claim 12 , wherein the multibeam element comprises one of a diffraction grating, a micro-reflective element and a micro-refractive element optically connected to the light guide to couple out the portion of the guided light.

14. The multiview display of claim 12 , further comprising a light source configured to provide the light to the light guide, the guided light having a non-zero propagation angle and being collimated according to a collimation factor to provide a predetermined angular spread of the guided light within the light guide.

15. The multiview display of claim 11 , wherein the multiview pixel of the multiview pixel array comprises a set of light valves, a sub-pixel of the multiview pixel comprising a light valve of the set.

16. A method of multiview backlight operation, the method comprising:
guiding light in a propagation direction along a length of a light guide; and
coupling a portion of the guided light out of the light guide using a multibeam element to provide a plurality of coupled-out light beams having different principal angular directions corresponding to respective different view directions of a multiview display,
wherein a size of the multibeam element is comparable to a size of a sub-pixel in a multiview pixel of the multiview display, and
wherein an inter-element distance between a pair of multibeam elements of the plurality of multibeam elements is equal to an inter-pixel distance between a corresponding pair of multiview pixels.

17. The method of multiview backlight operation of claim 16 , wherein the multibeam element comprises a diffraction grating optically coupled to the light guide to diffractively couple out the guided light portion.

18. The method of multiview backlight operation of claim 16 , further comprising modulating the coupled-out light beams using a plurality of light valves configured as the multiview pixel, a light valve of the light valve plurality corresponding to the sub-pixel of the multiview pixel.

Assignees

• Leia Inc

Inventors

• Fattal David A
• Ma Ming
• Li Xuejian

Classifications

• H04N13/302

  for viewing without the aid of special glasses, i.e. using autostereoscopic displays · CPC title

• G02B6/0036 Primary

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0061

  to provide homogeneous light output intensity · CPC title

• G02B6/0038 Primary

  Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide · CPC title

• G02B6/0035

  provided on the surface of the light guide or in the bulk of it · CPC title