# US 12,007,596 B2 · Light-guide optical element employing complementary coated partial reflectors, and light-guide optical element having reduced light scattering > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,596 B2 - Document ID: US12007596B2 - Status: Granted - Kind: B2 - Application number: 18/218,624 - Filed: 2023-07-06 - Published: 2023-11-02 - Granted: 2024-06-11 - Earliest claimed: 2019-12-05 - Assignees: Lumus Ltd. - Applicants: Lumus Ltd. - Inventors: Yochay Danziger; Elad Sharlin - Web page: https://patentgrep.com/patent/US12007596B2 ## CPC - G02B 1/10: Optical coatings produced by application to, or surface treatment of, optical elements (G02B1/08 takes precedence) - G02B 6/0035: {provided on the surface of the light guide or in the bulk of it} - G02B 6/0011: {the light guides being planar or of plate-like form} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - G02B 27/0172: {characterised by optical features} - G02B 2027/0112: {comprising device for genereting colour display} - G02B 2027/0118: {comprising devices for improving the contrast of the display / brillance control visibility} - G02B 2027/0194: {with combiner of laminated type, for optical or mechanical aspects} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A transparent substrate has two parallel faces and guides collimated image light by internal reflection. A first set of internal surfaces is deployed within the substrate oblique to the parallel faces. A second set of internal surfaces is deployed within the substrate parallel to, interleaved and in overlapping relation with the first set of internal surfaces. Each of the internal surfaces of the first set includes a first coating having a first reflection characteristic to be at least partially reflective to at least a first subset of components of incident light. Each of the internal surfaces of the second set includes a second coating having a second reflection characteristic complementary to the first reflection characteristic to be at least partially reflective to at least a second subset of components of incident light. The sets of internal surfaces cooperate to reflect all components of light from the first and second subsets. ## Claims ### Claim 1 An optical device, comprising: a light-transmitting substrate having at least a first pair of parallel major external surfaces for guiding light indicative of a collimated image by internal reflection at the major external surfaces; at least one internal surface deployed within the substrate, the internal surface having an end region associated with a first of the major external surfaces of the first pair of major external surfaces defining an interface region between the internal surface and the substrate; and an amount of a light absorbing material located at the interface region. ### Claim 2 (depends on 1) The optical device of claim 1, wherein the at least one internal surface includes a plurality of mutually parallel partially reflective surfaces. ### Claim 3 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is configured to couple light out of the substrate toward an eye of a viewer. ### Claim 4 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is configured to couple the light guided by internal reflection at the major external surfaces from a first guided direction to a second guided direction. ### Claim 5 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is configured to couple light into the substrate so as to propagate within the substrate by internal reflection. ### Claim 6 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is configured to couple light out of the substrate and into a second light-transmitting substrate so as to propagate within the second substrate by internal reflection. ### Claim 7 (depends on 1) The optical device of claim 1, wherein the amount of the light absorbing material is located at an indentation formed in the first of the major external surfaces at the interface region. ### Claim 8 (depends on 1) The optical device of claim 1, wherein the internal surface has a second end region associated with a second of the major external surfaces of the first pair of major external surfaces defining a second interface region between the internal surface and the substrate, the optical device further comprising: a second amount of a second light absorbing material located at the second interface region. ### Claim 9 (depends on 8) The optical device of claim 8, wherein the second amount of the second light absorbing material is located in a second indentation formed in the second of the major external surfaces at the interface region. ### Claim 10 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is oblique to the first pair of parallel major external surfaces. ### Claim 11 (depends on 1) The optical device of claim 1, wherein the at least one internal surface is perpendicular to the first pair of parallel major external surfaces. ### Claim 12 (depends on 1) The optical device of claim 1, wherein the substrate includes a second pair of parallel major external surfaces, the first and second pairs of parallel major external surfaces forming a rectangular cross-section, the substrate configured for guiding light by four-fold internal reflection at the pairs of major external surfaces. ### Claim 13 (depends on 12) The optical device of claim 12, wherein the at least one internal surface is oblique to a direction of elongation of the substrate. ### Claim 14 (depends on 12) The optical device of claim 12, wherein the at least one internal surface is oblique to the first pair of parallel major external surfaces and is perpendicular to the second pair of parallel major external surfaces. ### Claim 15 (depends on 12) The optical device of claim 12, wherein the at least one internal surface is oblique to the first pair of parallel major external surfaces and is oblique to the second pair of parallel major external surfaces. ### Claim 16 An optical device, comprising: a light-transmitting substrate having first and second pairs of parallel major external surfaces forming a rectangular cross-section, the substrate configured for guiding light by four-fold internal reflection at the pairs of major external surfaces; at least one internal surface deployed within the substrate oblique to a direction of elongation of the substrate, the internal surface having an end region associated with one of the major external surfaces of one of the pairs of major external surfaces to define an interface region between the internal surface and the substrate; and an amount of a light absorbing material located at the interface region. ### Claim 17 (depends on 16) The optical device of claim 16, wherein the at least one internal surface includes a plurality of mutually parallel partially reflective surfaces. ### Claim 18 (depends on 16) The optical device of claim 16, wherein the at least one internal surface is oblique to the first pair of parallel major external surfaces and perpendicular to the second pair of parallel major external surfaces. ### Claim 19 (depends on 16) The optical device of claim 16, wherein the at least one internal surface is oblique to the first pair of parallel major external surfaces and oblique to the second pair of parallel major external surfaces. ### Claim 20 (depends on 16) The optical device of claim 16, further comprising: a second amount of a second light absorbing material located at a blemish formed at an external region of the substrate that excludes the interface region.