# US 12,181,786 B2 · Wavelength conversion element and projection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,786 B2 - Document ID: US12181786B2 - Status: Granted - Kind: B2 - Application number: 17/859,047 - Filed: 2022-07-07 - Published: 2023-01-19 - Granted: 2024-12-31 - Earliest claimed: 2021-07-08 - Assignees: Coretronic Corporation - Applicants: Coretronic Corporation - Inventors: Fa-Chih Chen - Web page: https://patentgrep.com/patent/US12181786B2 ## 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)} - G02B 26/008: {in the form of devices for effecting sequential colour changes, e.g. colour wheels} - G03B 21/2066: {Reflectors in illumination beam (in projection beam G03B21/28)} - 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) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A wavelength conversion element includes a rotatable disc, a first spoiler structure and a second spoiler structure. The rotatable disc has a supporting surface and a back surface opposite to the supporting surface. The first spoiler structure is disposed on the supporting surface and arranged along a first track surrounding a center of the rotatable disc. The second spoiler structure is disposed on the back surface and arranged along a second track surrounding the center. A centroid of at least one of the first spoiler structure and the second spoiler structure is deviated from the center. A projection device adopting the aforementioned wavelength conversion element is also provided. The wavelength conversion element of the invention can reduce the initial unbalance and the projection device of the invention can improve the durability. ## Claims ### Claim 1 A wavelength conversion element, comprising a rotatable disc, a first spoiler structure and a second spoiler structure, wherein: the rotatable disc has a supporting surface and a back surface opposite to the supporting surface; the first spoiler structure is disposed on the supporting surface and arranged along a first track surrounding a center of the rotatable disc; and the second spoiler structure is disposed on the back surface and arranged along a second track surrounding the center, wherein a centroid of at least one of the first spoiler structure and the second spoiler structure is deviated from the center. ### Claim 2 (depends on 1) The wavelength conversion element according to claim 1, wherein the first spoiler structure comprises a plurality of first spoilers, and the second spoiler structure comprises a plurality of second spoilers. ### Claim 3 (depends on 2) The wavelength conversion element according to claim 2, wherein the first spoiler structure further comprises a first annular member overlapping with the first track, the plurality of first spoilers are distributed along the first tract, and one end of each of the plurality of first spoilers is connected to an outer annular surface of the first annular member, wherein the second spoiler structure further comprises a second annular member overlapping with the second track, the plurality of second spoilers are distributed along the second track, and one end of each of the plurality of second spoilers is connected to an outer annular surface of the second annular member. ### Claim 4 (depends on 3) The wavelength conversion element according to claim 3, wherein the first spoiler structure further comprises a first counterweight plate connected to the first annular member, and/or the second spoiler structure further comprises a second counterweight plate connected to the second annular member. ### Claim 5 (depends on 4) The wavelength conversion element according to claim 4, wherein a weight of the first counterweight plate is greater than a weight of each of the plurality of first spoilers, and/or a weight of the second counterweight plate is greater than a weight of each of the plurality of second spoilers. ### Claim 6 (depends on 3) The wavelength conversion element according to claim 3, wherein the first spoiler structure further comprises a first counterweight plate connected to the first annular member, the second spoiler structure further comprises a second counterweight plate connected to the second annular member, the first counterweight plate is disposed on an inner side of the first annular member and the second counterweight plate is disposed on an outer side of the second annular member, or the first counterweight plate is disposed on an outer side of the first annular member and the second counterweight plate is disposed on an inner side of the second annular member. ### Claim 7 (depends on 3) The wavelength conversion element according to claim 3, wherein the first annular member and the plurality of first spoilers are integrally formed, and the second annular member and the plurality of second spoilers are integrally formed. ### Claim 8 (depends on 2) The wavelength conversion element according to claim 2, wherein the plurality of first spoilers and the plurality of second spoilers are glue strips. ### Claim 9 (depends on 2) The wavelength conversion element according to claim 2, wherein the plurality of first spoilers are non-equidistantly distributed, and/or the plurality of second spoilers are non-equidistantly distributed. ### Claim 10 (depends on 2) The wavelength conversion element according to claim 2, wherein weights of the plurality of first spoilers are different, and/or weights of the plurality of second spoilers are different. ### Claim 11 (depends on 1) The wavelength conversion element according to claim 1, wherein the first spoiler structure and the second spoiler structure both comprise a first zone and a second zone, a mass density of the first zone is greater than a mass density of the second zone, the mass densities of the first zone and the second zone of the first spoiler structure have a first difference, the mass densities of the first zone and the second zone of the second spoiler structure have a second difference, and the first difference is greater than, equal to, or smaller than the second difference. ### Claim 12 (depends on 1) The wavelength conversion element according to claim 1, wherein at least one of the first spoiler structure and the second spoiler structure comprises a first zone and a second zone, a mass density of the first zone is greater than a mass density of the second zone, the rotatable disc further comprises an annular substrate and a plurality of wavelength conversion layers, the plurality of wavelength conversion layers are disposed on the annular substrate, and the wavelength conversion layer with the highest density occupies a first central angle of the annular substrate, wherein within the first central angle, an angle occupied by the first zone is smaller than an angle occupied by the second zone. ### Claim 13 (depends on 1) The wavelength conversion element according to claim 1, wherein at least one of the first spoiler structure and the second spoiler structure comprises a first zone and a second zone, a mass density of the first zone is greater than a mass density of the second zone, the rotatable disc further comprises an annular substrate, the annular substrate has a wavelength maintenance zone, and the wavelength maintenance zone occupies a central angle of the annular substrate, wherein within the central angle, an angle occupied by the first zone is greater than an angle occupied by the second zone. ### Claim 14 A projection device, comprising an illumination system, a light valve and a projection lens, the illumination system being configured to provide an illumination beam, the light valve being disposed on a transmission path of the illumination beam and configured to convert the illumination beam into an image beam, the projection lens being disposed on a transmission path of the image beam and configured to project the image beam, and the illumination system comprising an excitation light source and a wavelength conversion element, wherein: the excitation light source is configured to provide an excitation beam; and the wavelength conversion element is disposed on a transmission path of the excitation beam and comprises a rotatable disc, a first spoiler structure and a second spoiler structure, wherein: the rotatable disc has a supporting surface and a back surface opposite to the supporting surface; the first spoiler structure is disposed on the supporting surface and arranged along a first track surrounding a center of the rotatable disc; and the second spoiler structure is disposed on the back surface and arranged along a second track surrounding the center, wherein a centroid of at least one of the first spoiler structure and the second spoiler structure is deviated from the center. ### Claim 15 (depends on 14) The projection device according to claim 14, wherein the first spoiler structure comprises a plurality of first spoilers, and the second spoiler structure comprises a plurality of second spoilers. ### Claim 16 (depends on 15) The projection device according to claim 15, wherein the first spoiler structure further comprises a first annular member overlapping with the first track, the plurality of first spoilers are distributed along the first tract, and one end of each of the plurality of first spoilers is connected to an outer annular surface of the first annular member, wherein the second spoiler structure further comprises a second annular member overlapping with the second track, the plurality of second spoilers are distributed along the second track, and one end of each of the plurality of second spoilers is connected to an outer annular surface of the second annular member. ### Claim 17 (depends on 16) The projection device according to claim 16, wherein the first spoiler structure further comprises a first counterweight plate connected to the first annular member, and/or the second spoiler structure further comprises a second counterweight plate connected to the second annular member. ### Claim 18 (depends on 16) The projection device according to claim 16, wherein the first annular member and the plurality of first spoilers are integrally formed, and the second annular member and the plurality of second spoilers are integrally formed. ### Claim 19 (depends on 16) The projection device according to claim 16, wherein the plurality of first spoilers and the plurality of second spoilers are glue strips. ### Claim 20 (depends on 14) The projection device according to claim 14, wherein the first spoiler structure and the second spoiler structure both comprise a first zone and a second zone, a mass density of the first zone is greater than a mass density of the second zone, the mass densities of the first zone and the second zone of the first spoiler structure have a first difference, the mass densities of the first zone and the second zone of the second spoiler structure have a second difference, and the first difference is greater than, equal to, or smaller than the second difference.