# US 11,442,214 B2 · Optical device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,214 B2 - Document ID: US11442214B2 - Status: Granted - Kind: B2 - Application number: 16/982,313 - Filed: 2019-03-22 - Published: 2021-01-07 - Granted: 2022-09-13 - Earliest claimed: 2018-03-22 - Assignees: Nitto Denko Corporation - Applicants: Nitto Denko Corporation - Inventors: Kari Rinko - Web page: https://patentgrep.com/patent/US11442214B2 ## CPC - G02B 6/0035: {provided on the surface of the light guide or in the bulk of it} - G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces} - G02B 5/0247: {by means of voids or pores} - G02B 6/0023: {provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source} - G02B 6/0031: {Reflecting element, sheet or layer} - G02B 6/0043: {provided on the surface of the light guide} - G02B 6/0055: {Reflecting element, sheet or layer} - G02B 6/0063: {for extracting light out both the major surfaces of the light guide} - G02B 6/002: {by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces} - G02B 6/4243: {Mounting of the optical light guide into a groove (mounting optical light guides into a groove in general G02B6/3636)} - G02B 6/4259: {of the transparent type} - G09F 2013/1804: {Achieving homogeneous illumination} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS ## Abstract With a simple configuration, an optical device having an in-coupling function to a lightguide is provided. The optical device includes a light guiding layer; and in-coupling optics provided integrally with the light guiding layer to couple light from a light source to an incident edge of the light guiding layer. The in-coupling optics include an optical element that is convex toward the incident edge and an air cavity provided between the optical element and the incident edge. ## Claims ### Claim 1 An optical device, comprising: a non-patterned light guiding layer; in-coupling optics provided integrally with the non-patterned light guiding layer to couple light from a light source to an incident edge of the non-patterned light guiding layer; out-coupling optics through which light propagating in the light guiding layer is extracted to the outside, wherein the in-coupling optics include a first optical element that is convex toward the incident edge and an air cavity provided between the optical element and the incident edge, and the out-coupling optics include at least one embedded cavity to extract the light propagating in the light guiding layer to the outside via total internal reflection; and a low-refractive index layer provided on a light-extracting side of the non-patterned light guiding layer, wherein the out-coupling optics that includes the at least one embedded cavity is provided on the low-refractive index layer such that the low-refractive index layer is interposed between the at least one embedded cavity and a surface of the non-patterned light guiding layer on which the low-refractive index layer is provided. ### Claim 2 (depends on 1) The optical device of claim 1, wherein the in-coupling optics include a second optical element, identical to the first optical element, the first and second optical elements comprising a plurality of optical elements arranged along the incident edge, and apices of bumps of the optical elements are in contact with the incident edge, the incident edge constituting a uniform plane. ### Claim 3 (depends on 2) The optical device of claim 2, wherein surfaces of the plurality of optical elements that are on an opposite side to the bumps constitute a continuous plane. ### Claim 4 (depends on 1) The optical device of claim 1, wherein the in-coupling optics are adhesively bonded to the incident edge with an optical adhesive, or integrally formed with the light guiding layer. ### Claim 5 (depends on 1) The optical device of claim 1, wherein a refractive index of the first optical element is equal or close to a refractive index of the light guiding layer. ### Claim 6 (depends on 1) The optical device of claim 1, wherein the out-coupling optics include optical patterns which are discrete or at least partially continuous. ### Claim 7 (depends on 1) The optical device of claim 1, wherein the low-refractive index layer has at least one first portion having a refractive index lower than a refractive index of the non-patterned light guiding layer and at least one second portion having a refractive index higher than the refractive index of the at least one first portion. ### Claim 8 (depends on 7) The optical device of claim 7, wherein the at least one second portion includes a plurality of second portions, and the plurality of second portions are formed by burying apertures in the low-refractive index layer with a material having a refractive index higher than the refractive index of the at least one first portion. ### Claim 9 Light in-coupling optics to be integrated with a non-patterned lightguide, the light in-coupling optics comprising at least one optical cavity pattern to collimate light which is incident on the non-patterned lightguide in at least one of a transverse direction and a longitudinal direction within a two-dimensional plane, wherein uniformity of luminous flux along the transverse direction is adjusted in accordance with an out-coupling structure of the non-patterned lightguide, and the out-coupling structure includes at least one embedded cavity to extract the light which is incident on the non-patterned lightguide to the outside via total internal reflection, and a low-refractive index layer provided on a light-extracting side of the non-patterned light guide, wherein the out-coupling optics that includes the at least one embedded cavity is provided on the low-refractive index layer such that the low-refractive index layer is interposed between the at least one embedded cavity and a surface of the non-patterned light guide on which the low-refractive index layer is provided. ### Claim 10 (depends on 9) The light in-coupling optics of claim 9, wherein the optical cavity pattern has a cross-sectional shape of flat ball lens-type, round edge-type, or round ball lens-type. ### Claim 11 (depends on 9) The light in-coupling optics of claim 9, wherein the optical cavity pattern is integrally formed with or adhesively bonded to the lightguide. ### Claim 12 (depends on 9) The light in-coupling optics of claim 9, wherein the low-refractive index layer has at least one first portion having a refractive index lower than a refractive index of the non-patterned light guide and at least one second portion having a refractive index higher than the refractive index of the at least one first portion. ### Claim 13 (depends on 12) The light in-coupling optics of claim 12, wherein the at least one second portion includes a plurality of second portions, and the plurality of second portions are formed by burying apertures in the low-refractive index layer with a material having a refractive index higher than the refractive index of the at least one first portion.