# US 2019/0170926 A1 · Multibeam diffraction grating-based backlighting > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170926 A1 - Document ID: US20190170926A1 - Status: Published application - Kind: A1 - Application number: 16/270,422 - Filed: 2019-02-07 - Published: 2019-06-06 - Earliest claimed: 2016-01-28 - Assignees: Leia Inc. - Applicants: Leia Inc. - Inventors: David A. Fattal; Zhen Peng; Charles M. Santori - Web page: https://patentgrep.com/patent/US20190170926A1 ## CPC - G02B 6/0038: {Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide} - G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces} - G02B 6/005: {provided by one optical element, or plurality thereof, placed on the light output side of the light guide} - G02B 30/27: involving lenticular arrays - G02B 30/33: involving directional light or back-light sources - G02F 1/133615: {Edge-illuminating devices, i.e. illuminating from the side} - G02B 5/1861: {Reflection gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)} - G02B 5/1866: {Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract Multibeam diffraction grating-based backlighting includes a light guide and a multibeam diffraction grating at a surface of the light guide. The light guide is configured to guide light from a light source. The multibeam diffraction grating is configured to couple out a portion of the guided light using diffractive coupling and to direct the diffractively coupled out portion away from the light guide as a plurality of light beams with different principal angular directions having directions corresponding to view directions of a multiview display. ## Claims ### Claim 1 A multibeam diffraction grating-based backlight comprising: a light guide configured to guide light from a light source as guided light; and a plurality of multibeam diffraction gratings arranged across the light guide, each multibeam diffraction grating of the multibeam diffraction grating plurality being configured to couple out a portion of the guided light using diffractive coupling, the diffractively coupled-out portion of the guided light being directed away from a surface of the light guide as a plurality of light beams, a light beam of the light beam plurality having a different principal angular direction from other light beams of the light beam plurality, wherein different principal angular directions of the plurality of light beams correspond to directions of different views of a multiview display. ### Claim 2 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, wherein multibeam diffraction gratings of the multibeam diffraction grating plurality are arranged in rows and columns on the surface of the light guide. ### Claim 3 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, wherein the multibeam diffraction grating comprises a chirped diffraction grating. ### Claim 4 (depends on 3) The multibeam diffraction grating-based backlight of claim 3, wherein the chirped diffraction grating is a linearly chirped diffraction grating. ### Claim 5 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, wherein the multibeam diffraction grating comprises one of curved grooves and curved ridges that are spaced apart from one another. ### Claim 6 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, wherein the multibeam diffraction grating comprises a chirped diffraction grating having curved diffractive features, a curve of the curved diffractive features being configured to partially define the different principal angular directions of the plurality of light beams. ### Claim 7 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, further comprising the light source at an edge of the light guide, the guided light being light from the light source that is coupled into the edge of the light guide. ### Claim 8 (depends on 1) The multibeam diffraction grating-based backlight of claim 1, wherein the light guide and the multibeam diffraction grating are substantially transparent in a direction orthogonal to a direction in which the light is configured to be guided in the light guide. ### Claim 9 (depends on 1) An electronic display comprising the multibeam diffraction grating-based backlight of claim 1, wherein the portion of the guided light is configured to be diffractively coupled out by the multibeam diffraction grating is light corresponding to a pixel of the electronic display, the electronic display being the multiview display. ### Claim 10 (depends on 9) The electronic display of claim 9, further comprising a light valve configured to modulate the light beam of the plurality of light beams, the multibeam diffraction grating being between the light valve and the surface of the light guide. ### Claim 11 A multiview electronic display comprising: a plate light guide configured to guide light from a light source as guided light; a plurality of diffraction gratings distributed across the plate light guide, a multibeam diffraction grating of the diffraction grating plurality being configured to diffractively couple out a portion of the guided light as a plurality of light beams having a corresponding plurality of different principal angular directions associated with different views of the multiview electronic display; and a light valve array configured to modulate the light beams of the light beam plurality to provide a plurality of modulated light beams, wherein the plurality of modulated light beams having different principal angular directions represent pixels of the different views of the multiview electronic display, different ones of the modulated light beams having directions corresponding to different ones of the different views of the multiview electronic display. ### Claim 12 (depends on 11) The multiview electronic display of claim 11, wherein diffraction gratings of the diffraction grating plurality including the multibeam diffraction grating are arranged in rows and columns at a surface of the plate light guide. ### Claim 13 (depends on 11) The multiview electronic display of claim 11, wherein the multibeam diffraction grating comprises a chirped diffraction grating having curved diffractive features. ### Claim 14 (depends on 11) The multiview electronic display of claim 11, wherein the light valve array comprises a plurality of liquid crystal light valves. ### Claim 15 (depends on 11) The multiview electronic display of claim 11, further comprising the light source, the guided light being light from the light source that is coupled into an edge of the plate light guide. ### Claim 16 A method of operating a multiview display, the method comprising: guiding light in a light guide as guided light; and diffractively coupling out a portion of the guided light using a multibeam diffraction grating at a surface of the light guide to produce a plurality of light beams, each light beam of the light beam plurality propagating away from the light guide surface at a different principal angular direction from other light beams of the light beam plurality, wherein different principal angular directions of light beams of the light beam plurality collectively have principal angular directions corresponding to directions of different views of the multiview display. ### Claim 17 (depends on 16) The method of operating a multiview display of claim 16, further comprising modulating the plurality of light beams using a corresponding plurality of light valves, the modulated light beams forming pixels associated with the different views of the multiview display. ### Claim 18 (depends on 16) The method of operating a multiview display of claim 16, wherein the multibeam diffraction grating is a member of a plurality of multibeam diffraction grating, multibeam diffraction gratings of the multibeam diffraction grating plurality being arranged in rows and columns on the light guide surface. ### Claim 19 (depends on 16) The method of operating a multiview display of claim 16, wherein the multibeam diffraction grating comprises a chirped diffraction grating having curved diffractive features, a curve of the curved diffractive features partially defining the different principal angular directions of light beams of the light beam plurality. ### Claim 20 (depends on 16) The method of operating a multiview display of claim 16, further comprising providing the light to be guided in the light guide using a light source coupled to an edge of the light guide.