Three-dimensional (3d) electronic display

Patent metadata

Field	Value
Publication number	US-2018011237-A1
Application number	US-201715665256-A
Country	US
Kind code	A1
Filing date	Jul 31, 2017
Priority date	Jan 28, 2015
Publication date	Jan 11, 2018
Grant date	—

Abstract

Three-dimensional (3D) electronic displays provide different 3D views and employ one or both of an array of multibeam diffraction gratings arranged in offset rows and light valves having color filters. The displays include a plate light guide configured to guide light beams at a non-zero propagation angle, a multibeam diffraction grating configured to couple out a portion of the guided light beams as a plurality of light beams having different principal angular directions representing the different 3D views, and light valves configured to modulate the differently directed, coupled-out light beams. The multibeam diffraction grating may be a member of the array arranged in offset rows and the display may further include light valves having color filters. Alternately, the light valves include color filters and the display may further include the array of multibeam diffraction gratings arranged in offset rows.

First claim

What is claimed is:

1 . A three-dimensional (3D) electronic display comprising:
a plate light guide configured to guide a light beam at a non-zero propagation angle; an array of multibeam diffraction gratings arranged in a plurality of offset rows, a multibeam diffraction grating of the array being configured to diffractively couple out a portion of the guided light beam as a plurality of coupled-out light beams having different principal angular directions corresponding to different views of the 3D electronic display; and a light valve array configured to modulate the plurality of coupled-out light beams corresponding to the different views of the 3D electronic display, the modulated plurality of coupled-out light beams representing pixels of the 3D electronic display.

2 . The 3D electronic display of claim 1 , wherein the multibeam diffraction grating comprises a linearly chirped diffraction grating.

3 . The 3D electronic display of claim 1 , wherein the multibeam diffraction grating is at a surface of the plate light guide, the multibeam diffraction grating having a substantially rectangular shape with diffractive features comprising one or both of curved grooves in the plate light guide surface and curved ridges on the plate light guide surface.

4 . The 3D electronic display of claim 1 , wherein a first row of the multibeam diffraction grating array is offset in a row direction relative to a second row of the multibeam diffraction grating array adjacent to the first row, the offset being about one half of a pitch of the multibeam diffraction gratings in the first row of the multibeam diffraction grating array.

5 . The 3D electronic display of claim 1 , wherein a center-to-center spacing between adjacent offset rows of the multibeam diffraction grating array is about one half of a pitch of the multibeam diffraction gratings in the offset rows of the multibeam diffraction grating array.

6 . The 3D electronic display of claim 1 , wherein a subset of the light valves of the light valve array is configured to modulate the plurality of coupled-out light beams from a selected multibeam diffraction grating of the multibeam diffraction grating array, the light valve subset representing a super-pixel of the 3D electronic display, each light valve of the super-pixel being configured to modulate a different coupled-out light beam of the selected multibeam diffraction grating.

7 . The 3D electronic display of claim 6 , wherein the super-pixel comprises a rectangular arrangement of the light valves of the subset, the rectangular arrangement having about half as many light valves in a direction substantially orthogonal to a row direction of the plurality of offset rows of the multibeam diffraction grating array than in a the row direction.

8 . The 3D electronic display of claim 1 , further comprising a plurality of light sources of different colors both laterally displaced from one another in a row direction of the offset rows of the multibeam diffraction grating array and coupled to the plate light guide, each light source being configured to produce a light beam of a specific color different from the colors produced by other light sources of the light source plurality, wherein the plate light guide is configured to guide the different color light beams at respective non-zero propagation angles determined by the lateral displacement of the different color light sources, wherein the respective non-zero propagation angles of the different color guided light beams is configured to provide coupled-out light beams of each of the different colors in each of the different views of the 3D electronic display.

9 . The 3D electronic display of claim 8 , wherein the light valves of the light valve array comprise liquid crystal light valves, a first liquid crystal light valve having a color filter that differs in color from a color filter of a second liquid crystal light valve of the light valve array.

10 . A three-dimensional (3D) color electronic display, comprising:
a plate light guide configured to guide light beams of different colors at different color-dependent propagation angles; a multibeam diffraction grating at a surface of the plate light guide configured to diffractively couple out a portion of the guided light beams of each color as a separate plurality of coupled-out light beams of a respective different color, the coupled-out light beams of the respective different color separate pluralities having different principal angular directions representing different views of the 3D color electronic display; and a plurality of light valves configured to modulate the coupled-out light beams of the respective different color separate pluralities, the light valves of the light valve plurality having color filters corresponding to the respective different colors of the coupled-out light beams.

11 . The 3D color electronic display of claim 10 , wherein the principal angular directions of the coupled-out light beams is a function of the color-dependent propagation angle of the guided light beams.

12 . The 3D color electronic display of claim 10 , wherein the different colors of the guided light beams comprise red, green and blue of a red-green-blue (RGB) color model, and wherein the color filters include a red color filter, a green color filter, and a blue color filter corresponding to the RGB color model, and wherein a view of the 3D color electronic display includes a red light beam, a green light beam and a blue light beam.

13 . The 3D color electronic display of claim 10 , wherein the multibeam diffraction grating has a substantially rectangular shape with diffractive features comprising one or both of curved grooves in the plate light guide surface and curved ridges on the plate light guide surface.

14 . The 3D color electronic display of claim 10 , wherein the multibeam diffraction grating is a member of an array of multibeam diffraction gratings arranged in a plurality of offset rows at the plate light guide surface, adjacent rows of the multibeam diffraction gratings being offset from one another in a row direction by about one half of a pitch of the multibeam diffraction gratings of the adjacent rows.

15 . The 3D color electronic display of claim 14 , wherein a spacing between the adjacent rows of the multibeam diffraction gratings is about one half of the pitch of the multibeam diffraction gratings.

16 . The 3D color electronic display of claim 10 , further comprising a light source having a plurality of optical emitters configured to emit the light beams of different colors, the light source being coupled to the plate light guide, wherein the optical emitters of the respective different colors are laterally offset from one another to determine the different color-dependent propagation angles of the different color guided light beams.

17 . A method of 3D electronic display operation, the method comprising:
guiding light in a plate light guide as a light beam at a non-zero propagation angle; diffractively coupling out a portion of the guided light beam using an array of multibeam diffraction gratings arranged in offset rows on the plate light guide, wherein diffractively coupling out the guided light beam portion comprises producing a plurality of coupled-out light beams that are directed away from the plate light guide in a plurality of different principal angular directions corresponding to different views of the 3D electronic display; and modulating the plurality of coupled-out light beams using a plurality of light valves, the modulated plurality of coupled-out l

Assignees

• Leia Inc

Inventors

• Fattal David A

Classifications

• G02B6/0038

  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

• G02B5/18

  Diffraction gratings {(holographic optical elements G02B5/32, G03H; integrally combined with optical fibres G02B6/02057; for coupling light guides G02B6/34; integrally combined with optical integrated light guides G02B6/12; grating systems G02B27/44)} · CPC title

• G02B30/40 Primary

  giving the observer of a single two-dimensional [2D] image a perception of depth · CPC title

• G02B30/27

  involving lenticular arrays · CPC title

• G02B6/0035 Primary

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