# US 11,906,891 B2 · Projection screen and processing method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,891 B2 - Document ID: US11906891B2 - Status: Granted - Kind: B2 - Application number: 17/286,444 - Filed: 2019-09-26 - Published: 2021-12-16 - Granted: 2024-02-20 - Earliest claimed: 2018-10-18 - Assignees: Appotronics Corporation Limited - Applicants: Appotronics Corporation Limited - Inventors: Lin Wang; Wei Sun; Jie Wang; Fei Hu; Yi Li - Web page: https://patentgrep.com/patent/US11906891B2 ## CPC - G02B 5/1895: {such optical elements having dioptric power} - G03B 21/60: characterised by the nature of the surface - G02B 3/0012: {characterised by the manufacturing method} - G02B 3/0056: {arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085)} - G02B 5/003: {Light absorbing elements} - G02B 5/0242: {by means of dispersed particles} - G02B 5/1857: {using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams} - G02B 5/1861: {Reflection gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)} - G02B 5/22: Absorbing filters {(G02B5/201 - G02B5/208 take precedence)} - G03B 21/602: Lenticular screens (G03B21/625 takes precedence) - G02B 1/04: made of organic materials, e.g. plastics (G02B1/08 takes precedence) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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) ## Abstract A projection screen and a processing method therefor, wherein the projection screen comprises, in sequence from the incident side of projection light, a diffusion layer, a microlens array and a substrate. The inner side of the substrate is provided with a Fresnel microstructure, and part of the surface of the Fresnel microstructure is provided with a reflecting layer while the remaining part of the surface is a light absorbing layer. The microlens array is used for focusing the projection light on the reflecting layer. The reflecting layer is used for reflecting projection light back to the field of view of viewers. Ambient light is mostly absorbed by the light absorbing layer. The settings of the structure and dimension of the microlens array enable the projection light to be only incident onto the reflecting layer of the Fresnel microstructure and the ambient light to be mostly absorbed by the light absorbing layer. ## Claims ### Claim 1 A projection screen comprising a diffusion layer, a microlens array, and a substrate that are arranged sequentially from an incident side of projection light, wherein an inner side of the substrate is provided with an Fresnel microstructure, a part of a surface of the Fresnel microstructure is provided with reflective layers, and a remaining part of the surface of the Fresnel microstructure is provided with light-absorbing layers, and wherein the microlens array is configured to focus the projection light on the reflective layers, and the reflective layers are configured to reflect the projection light back to a field of view of a viewer. ### Claim 2 (depends on 1) The projection screen according to claim 1, wherein one of the reflective layers is provided between two adjacent light-absorbing layers of the light-absorbing layers. ### Claim 3 (depends on 1) The projection screen according to claim 1, wherein the microlens array comprises a plurality of microlens units, and each of the reflective layers is arranged at a position corresponding to a focal plane of one of the plurality of microlens units, such that the reflected light is capable of being located at a position of the focal plane of the corresponding microlens unit. ### Claim 4 (depends on 3) The projection screen according to claim 3, wherein assuming that a denotes an interval between vertexes of two adjacent microlens units of the plurality of microlens units, d denotes a focal length of each of the microlens units, and r denotes a radius of curvature of the microlens unit, when a is constant, d is variable and r is variable; or when d is constant, a is variable and r is variable. ### Claim 5 (depends on 4) The projection screen according to claim 4, wherein the microlens array is configured in an aperiodic arrangement. ### Claim 6 (depends on 3) The projection screen according to claim 3, wherein a pitch (P) of each of the plurality of microlens units of the microlens array is 100 μm. ### Claim 7 (depends on 1) The projection screen according to claim 1, wherein the microlens array arranged on the substrate has a rotational symmetric structure which has a shape of arcs. ### Claim 8 (depends on 1) The projection screen according to claim 1, wherein the diffusion layer is attached to an outer side of the microlens array. ### Claim 9 (depends on 1) The projection screen according to claim 1, wherein an outer side of the microlens array is roughened to form the diffusion layer. ### Claim 10 (depends on 1) A processing method for the projection screen according to claim 1, comprising: forming the microlens array, which comprises processing the microlens array on a transparent substrate by using an ion exchange process, a photosensitive glass process, a holographic process, an Fresnel zone lens process, or a photoresist-thermal fusion process; forming an Fresnel reflective structure, which comprises forming the Fresnel microstructure, by an imprinting process or UV glue transferring process, on a side of the transparent substrate that is opposite to another side of the transparent substrate where the microlens array is formed, uniformly coating a preformed white reflective coating material on a surface of the Fresnel microstructure, then irradiating the white reflective coating material with light beams to cure a part of the white reflective coating material irradiated by the light beams, an irradiation direction of the light beams being orientated in an incident direction of light emitted from a projector, and removing another part of the white reflective coating material that is not irradiated by the light beams; and forming the light-absorbing layers, which comprises adding a black organic dye and an inorganic pigment in a UV glue, coating a formed black absorbing material on the surface of the Fresnel microstructure where the another part of the white reflective coating material non-irradiated by the light beams is removed, and obtaining a main structure of the projection screen through light-curing. ### Claim 11 (depends on 10) The processing method according to claim 10, further comprising: attaching the diffusion layer to a side of the microlens array close to the viewer, or directly roughening a lens surface of the microlens array to form the diffusion layer. ### Claim 12 (depends on 10) The processing method according to claim 10, wherein one of the reflective layers is provided between two adjacent light-absorbing layers of the light-absorbing layers. ### Claim 13 (depends on 1) A processing method for the projection screen according to claim 1, comprising: forming the microlens array, which comprises processing the microlens array on a transparent substrate by using an ion exchange process, a photosensitive glass process, a holographic process, an Fresnel zone lens process, or a photoresist-thermal fusion process; forming an Fresnel reflective structure, which comprises forming the Fresnel microstructure, by an imprinting process or UV glue transferring process, on a side of the transparent substrate that is opposite to another side of the transparent substrate where the microlens array is formed; forming light-absorbing layers, which comprises adding a black organic dye and an inorganic pigment in a UV glue, coating a formed black absorbing material on a surface of the Fresnel microstructure, and removing a part of the black absorbing material irradiated by light beams and remaining another part of the black absorbing material that is not irradiated by the light beams, to form the light-absorbing layers; and filling a reflective coating material between every two adjacent light-absorbing layers of the light-absorbing layers to obtain a main structure of the projection screen. ### Claim 14 (depends on 13) The processing method according to claim 13, further comprising: attaching the diffusion layer to a side of the microlens array close to the viewer, or directly roughening a lens surface of the microlens array, to form the diffusion layer. ### Claim 15 (depends on 13) The processing method according to claim 13, wherein the microlens array comprises a plurality of microlens units, and each of the reflective layers is arranged at a position corresponding to a focal plane of one of the plurality of microlens units. ### Claim 16 (depends on 1) The projection screen according to claim 1, wherein each of the reflective layers is a white reflective coating material that comprises reflective particles, diffusion particles, negative photoresist, adhesive glue, and auxiliary material. ### Claim 17 (depends on 16) The projection screen according to claim 16, wherein a reflectivity of a reflective surface of each of the reflective layers is controlled by adjusting a content of the reflective particles in the white reflective coating material. ### Claim 18 (depends on 1) The projection screen according to claim 1, wherein each of the light-absorbing layers comprises UV glue, and the UV glue comprises black organic dye and inorganic pigment.