# US 12,111,499 B2 · Light guide member > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,499 B2 - Document ID: US12111499B2 - Status: Granted - Kind: B2 - Application number: 17/861,909 - Filed: 2022-07-11 - Published: 2023-01-26 - Granted: 2024-10-08 - Earliest claimed: 2021-07-16 - Assignees: Denso Corporation; Toyota Jidosha Kabushiki Kaisha; MIRISE Technologies Corporation - Applicants: Denso Corporation; Toyota Jidosha Kabushiki Kaisha; MIRISE Technologies Corporation - Inventors: Hiroshi Ando; Kodai Takeda - Web page: https://patentgrep.com/patent/US12111499B2 ## CPC - G02B 6/002: {by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces} - G02B 6/34: utilising prism or grating {(G02B6/293 takes precedence)} - G02B 5/045: {Prism arrays} - G02B 27/0018: {with means for preventing ghost images (anti-reflection coatings G02B1/11)} - G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A light guide member includes an incident portion, an emission portion, a reflection portion, and an inclined portion. An internal reflection angle inside the reflection portion and the emission portion is larger than an incident angle of an external light with respect to a first normal line that is a normal line of the emission portion. A first inclination angle that is an inclination angle of the incident portion with respect to the first normal line is smaller than the internal reflection angle. A height from the emission portion to a second side of the incident portion is larger than a distance between the emission portion and the reflection portion. A second inclination angle that is an inclination angle of the inclined portion with respect to the first normal line is smaller than the internal reflection angle. ## Claims ### Claim 1 A light guide member comprising: an incident portion having a first side and a second side opposite to the first side, and configured to allow an external light from an external scene to be incident on; an emission portion being in contact with the first side of the incident portion to be inclined with respect to the incident portion, and configured to transmit a part of the external light incident on the emission portion and reflect another part of the external light incident on the emission portion; a reflection portion disposed in parallel with the emission portion to be separated from the emission portion, and configured to reflect the external light incident on the reflection portion; and an inclined portion connecting the second side of the incident portion and a side of the reflection portion close to the incident portion, wherein an internal reflection angle inside the reflection portion and the emission portion is larger than an incident angle of the external light in a light guide cross section that is a plane defined by a first normal line and a second normal line, the first normal line is a normal line of the emission portion, the second normal line is a normal line of the incident portion, and the incident angle is an angle of the external light with respect to the first normal line, a first inclination angle that is an inclination angle of the incident portion with respect to the first normal line is smaller than the internal reflection angle, a height from the emission portion to the second side of the incident portion in a direction parallel to the first normal line is larger than a distance between the emission portion and the reflection portion, and a second inclination angle that is an inclination angle of the inclined portion with respect to the first normal line is smaller than the internal reflection angle, wherein the inclined portion is inclined so as to intersect a surface of the reflection portion. ### Claim 2 (depends on 1) The light guide member according to claim 1, wherein the height is equal to or less than twice the distance. ### Claim 3 (depends on 1) The light guide member according to claim 1, wherein a sum of the first inclination angle and the internal reflection angle is smaller than π/2. ### Claim 4 (depends on 1) The light guide member according to claim 1, wherein the emission portion has a first periodic structure. ### Claim 5 (depends on 4) The light guide member according to claim 4, wherein the incident portion has the first periodic structure. ### Claim 6 (depends on 4) The light guide member according to claim 4, wherein the first periodic structure includes a diffraction grating or a hologram. ### Claim 7 (depends on 1) The light guide member according to claim 1, wherein the emission portion has a double structure including a reflection and transmission portion and a second periodic structure. ### Claim 8 (depends on 7) The light guide member according to claim 7, wherein the incident portion has the second periodic structure. ### Claim 9 (depends on 8) The light guide member according to claim 8, wherein the second periodic structure includes a prism array or a prism sheet in which a plurality of prisms are arranged along the light guide cross section. ### Claim 10 (depends on 9) The light guide member according to claim 9, wherein each of the plurality of prisms in the emission portion includes an emission side surface configured to emit the external light and an emission facing surface that faces the emission side surface, each of the plurality of prisms in the incident portion includes an incident side surface configured to allow the external light to be incident on and an incident facing surface that faces the incident side surface, and the emission side surface is configured to be parallel to the incident side surface. ### Claim 11 (depends on 10) The light guide member according to claim 10, wherein the emission facing surface is configured to be parallel to the incident facing surface. ### Claim 12 (depends on 1) The light guide member according to claim 1, wherein the internal reflection angle is a total reflection angle. ### Claim 13 (depends on 1) The light guide member according to claim 1, wherein the inclined portion has a light absorbing member. ### Claim 14 (depends on 1) The light guide member according to claim 1, wherein the incident angle has a range from a first incident angle to a second incident angle larger than the first incident angle, and the internal reflection angle is a reflection angle when the incident angle is the second incident angle. ### Claim 15 (depends on 1) The light guide member according to claim 1, wherein the internal reflection angle has a range from a first reflection angle to a second reflection angle larger than the first reflection angle, and the second inclination angle is smaller than the first reflection angle. ### Claim 16 (depends on 1) The light guide member according to claim 1, wherein the inclined portion includes a first end portion connected to the reflection portion and a second end portion connected to the second side, and the inclined portion is inclined in such a manner that a distance in the direction parallel to the first normal line between the inclined portion and the emission portion increases from the first end portion to the second end portion.