# US 11,442,349 B2 · Wavelength conversion element, method of manufacturing wavelength conversion element, light source device, and projector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,349 B2 - Document ID: US11442349B2 - Status: Granted - Kind: B2 - Application number: 17/154,633 - Filed: 2021-01-21 - Published: 2021-07-22 - Granted: 2022-09-13 - Earliest claimed: 2020-01-22 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Tomohiro Yokoo - Web page: https://patentgrep.com/patent/US11442349B2 ## CPC - G03B 21/204: {using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197)} - F21V 7/30: the coatings comprising photoluminescent substances - F21V 29/505: of reflectors - G03B 21/16: Cooling; Preventing overheating - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR ## Abstract A wavelength conversion element includes: a wavelength conversion layer that is formed with a plurality of pores and that is excited by light in a first wavelength band to generate light in a second wavelength band different from the light in the first wavelength band; a first bonding layer formed at a first surface of the wavelength conversion layer; a second bonding layer bonded to the first bonding layer; and a reflection member that is formed at the second bonding layer and that reflects the light in the first wavelength band or the light in the second wavelength band. The first surface of the wavelength conversion layer is formed with a recess. A part of the first bonding layer is formed at the recess. The second bonding layer is formed to cover the recess. The first bonding layer and the second bonding layer are plasma polymerized films. ## Claims ### Claim 1 A wavelength conversion element comprising: a wavelength conversion layer that is formed with a plurality of pores and that is excited by light in a first wavelength band to generate light in a second wavelength band different from the light in the first wavelength band; a first bonding layer formed at a first surface of the wavelength conversion layer; a second bonding layer bonded to the first bonding layer; and a reflection member that is formed at the second bonding layer and that reflects the light in the first wavelength band or the light in the second wavelength band, wherein the first surface of the wavelength conversion layer is formed with a recess, a part of the first bonding layer is formed at the recess, the second bonding layer is formed so as to cover the recess, and the first bonding layer and the second bonding layer are plasma polymerized films. ### Claim 2 (depends on 1) The wavelength conversion element according to claim 1, further comprising: a support substrate; and a third bonding layer that bonds the support substrate and the reflection member. ### Claim 3 (depends on 2) The wavelength conversion element according to claim 2, wherein a refractive index of the first bonding layer is lower than a refractive index of the wavelength conversion layer. ### Claim 4 (depends on 3) A light source device comprising: the wavelength conversion element according to claim 3; and a light source that emits the light in the first wavelength band toward the wavelength conversion element. ### Claim 5 (depends on 4) A projector comprising: the light source device according to claim 4; a light modulation device that forms image light by modulating light from the light source device according to image information; and a projection optical system that projects the image light. ### Claim 6 (depends on 2) A light source device comprising: the wavelength conversion element according to claim 2; and a light source that emits the light in the first wavelength band toward the wavelength conversion element. ### Claim 7 (depends on 6) A projector comprising: the light source device according to claim 6; a light modulation device that forms image light by modulating light from the light source device according to image information; and a projection optical system that projects the image light. ### Claim 8 (depends on 1) The wavelength conversion element according to claim 1, wherein a refractive index of the first bonding layer is lower than a refractive index of the wavelength conversion layer. ### Claim 9 (depends on 8) A light source device comprising: the wavelength conversion element according to claim 8; and a light source that emits the light in the first wavelength band toward the wavelength conversion element. ### Claim 10 (depends on 9) A projector comprising: the light source device according to claim 9; a light modulation device that forms image light by modulating light from the light source device according to image information; and a projection optical system that projects the image light. ### Claim 11 (depends on 1) A light source device comprising: the wavelength conversion element according to claim 1; and a light source that emits the light in the first wavelength band toward the wavelength conversion element. ### Claim 12 (depends on 11) A projector comprising: the light source device according to claim 11; a light modulation device that forms image light by modulating light from the light source device according to image information; and a projection optical system that projects the image light. ### Claim 13 A method of manufacturing a wavelength conversion element, the method comprising: a preparation step of preparing a wavelength conversion layer that has a plurality of pores, a first surface, and a recess formed at the first surface and that is excited by light in a first wavelength band to generate light in a second wavelength band different from the light in the first wavelength band; a first step of forming a first bonding layer at the first surface of the wavelength conversion layer; a second step of forming a reflection member at a second surface of a substrate; a third step of forming a second bonding layer at the reflection member; a fourth step of applying energy to the first bonding layer and the second bonding layer; a fifth step of pressing the first bonding layer and the second bonding layer, and bonding the first bonding layer and the second bonding layer so that the recess is covered by the second bonding layer; and a sixth step of separating the reflection member and the substrate, wherein in the first step, a part of the first bonding layer is formed in the recess. ### Claim 14 (depends on 13) The method of manufacturing a wavelength conversion element according to claim 13, the method further comprising: after the sixth step, a seventh step of bonding a bonded body and a support substrate via a third bonding layer, the bonded body being obtained by bonding the wavelength conversion layer and the reflection member by the first bonding layer and the second bonding layer. ### Claim 15 (depends on 14) The method of manufacturing the wavelength conversion element according to claim 14, wherein in the first step, the first bonding layer is formed using a material having a lower refractive index than the wavelength conversion layer. ### Claim 16 (depends on 13) The method of manufacturing the wavelength conversion element according to claim 13, wherein in the first step, the first bonding layer is formed using a material having a lower refractive index than the wavelength conversion layer.