# US 2020/0401034 A1 · Screen and projection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401034 A1 - Document ID: US20200401034A1 - Status: Published application - Kind: A1 - Application number: 16/979,264 - Filed: 2018-10-16 - Published: 2020-12-24 - Earliest claimed: 2018-03-09 - Assignees: Appotronics Corporation Limited - Applicants: Appotronics Corporation Limited - Inventors: LIN WANG; YI LI - Web page: https://patentgrep.com/patent/US20200401034A1 ## CPC - G02B 5/0284: {used in reflection} - G03B 21/60: characterised by the nature of the surface - G02B 5/003: {Light absorbing elements} - G02B 5/0273: {characterized by the use} - G02B 5/124: plural reflecting elements forming part of a unitary plate or sheet - G03B 21/28: Reflectors in projection beam {(in illumination beam G03B21/2066)} - G03B 21/602: Lenticular screens (G03B21/625 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 screen capable of reflecting projected light from a projector to a viewer's field of view, at least comprising a surface diffusion layer (14), a transmission light-absorbing layer (13) and a projection reflective layer (12) which are stacked sequentially from the incident side of the projected light. The projection reflective layer (12) selectively reflects the projected light. The transmission light-absorbing layer (13) comprises light-absorbing material particles, and the distribution of the light-absorbing material particles in the transmission light-absorbing layer (13) is set according to the distribution of the Fresnel loss of the projected light on the surface of the screen, such that the light transmittance of the transmission light-absorbing layer (13) is higher in the region where the Fresnel loss is larger. Further disclosed is a projection system comprising the screen. The screen and the projection system have high contrast and high brightness uniformity. ## Claims ### Claim 1 A screen capable of reflecting projection light from a projector to viewing field of a viewer, comprising at least a surface diffusion layer, a transmitting and light-absorbing layer, and a projection-reflecting layer stacked sequentially from an incident side of the projection light, wherein the projection-reflecting layer is configured to selectively reflect the projection light; and wherein the transmitting and projection-reflecting layer comprises light absorbing material particles, and distribution of the light absorbing material particles in the transmission light absorbing layer is set according to distribution of a Fresnel loss of the projection light on a surface of the screen, so that the greater a Fresnel loss in a region of the screen, the higher a transmittance of a portion of the transmitting and light-absorbing layer in the region. ### Claim 2 (depends on 1) The screen of claim 1, wherein the transmitting and projection-reflecting layer comprises a light-absorbing medium layer and a transparent medium layer, wherein the light-absorbing medium layer comprises light absorbing material particles distributed with a uniform density; a thickness of the light-absorbing medium layer in a region is inversely proportional to a Fresnel reflectance of the screen surface in the region for the projection light; a total thickness of the light-absorbing medium layer and the transparent medium layer is a fixed value; and an absolute value of a difference between refractive indexes of the light-absorbing medium layer and the transparent medium layer is not greater than 0.2. ### Claim 3 (depends on 2) The screen of claim 2, wherein in a horizontal direction, the thickness of the light-absorbing medium layer gradually decreases from a center to both edges of the screen, and/or in a vertical direction, the thickness of the light-absorbing medium layer gradually decreases from a bottom to a top of the screen. ### Claim 4 (depends on 2) The screen of claim 2, wherein a variation of the thickness of the light-absorbing medium layer in a horizontal direction conforms to a linear distribution or a curvilinear distribution, or a variation of the thickness of the light-absorbing medium layer in a vertical direction conforms to a linear distribution or a curvilinear distribution. ### Claim 5 (depends on 2) The screen of claim 2, wherein the light-absorbing medium layer comprises a light-absorbing dye, and a maximum thickness difference between different regions of the light-absorbing medium layer decreases with increasing of a proportion of the light absorbing dye. ### Claim 6 (depends on 2) The screen of claim 2, wherein the transparent medium layer is a transparent glue layer. ### Claim 7 (depends on 1) The screen of claim 1, the projection-reflecting layer comprises a total reflection layer and a light-absorbing layer stacked sequentially from the incident side of the projection light, wherein the light absorbing layer is capable of absorbing light; the total reflection layer comprises a microstructure layer, and the microstructure layer comprises a plurality of microstructure units; and the microstructure unit comprises a first plane at a lower side and a second plane at an upper side, wherein the first plane intersects the second plane, the plurality of microstructure units form a serrated structure, and total internal reflection of the projection light continuously happens on the first plane and the second plane. ### Claim 8 (depends on 7) The screen of claim 7, wherein the microstructure layer comprises a rotationally symmetric structure, and a rotation center axis is perpendicular to a plane of the screen and is located below the screen. ### Claim 9 (depends on 1) The screen of claim 1, wherein the projection-reflecting layer is a Fresnel reflection layer. ### Claim 10 A projection system, comprising a projector and a screen; the screen capable of reflecting projection light from a projector to viewing field of a viewer, comprising at least a surface diffusion layer, a transmitting and light-absorbing layer, and a projection-reflecting layer stacked sequentially from an incident side of the projection light, wherein the projection-reflecting layer is configured to selectively reflect the projection light; and wherein the transmitting and projection-reflecting layer comprises light absorbing material particles, and distribution of the light absorbing material particles in the transmission light absorbing layer is set according to distribution of a Fresnel loss of the projection light on a surface of the screen, so that the greater a Fresnel loss in a region of the screen, the higher a transmittance of a portion of the transmitting and light-absorbing layer in the region. ### Claim 11 (depends on 10) The projection system of claim 10, wherein the transmitting and projection-reflecting layer comprises a light-absorbing medium layer and a transparent medium layer, wherein the light-absorbing medium layer comprises light absorbing material particles distributed with a uniform density; a thickness of the light-absorbing medium layer in a region is inversely proportional to a Fresnel reflectance of the screen surface in the region for the projection light; a total thickness of the light-absorbing medium layer and the transparent medium layer is a fixed value; and an absolute value of a difference between refractive indexes of the light-absorbing medium layer and the transparent medium layer is not greater than 0.2. ### Claim 12 (depends on 11) The projection system of claim 11, wherein in a horizontal direction, the thickness of the light-absorbing medium layer gradually decreases from a center to both edges of the screen, and/or in a vertical direction, the thickness of the light-absorbing medium layer gradually decreases from a bottom to a top of the screen. ### Claim 13 (depends on 11) The projection system of claim 11, wherein a variation of the thickness of the light-absorbing medium layer in a horizontal direction conforms to a linear distribution or a curvilinear distribution, or a variation of the thickness of the light-absorbing medium layer in a vertical direction conforms to a linear distribution or a curvilinear distribution. ### Claim 14 (depends on 11) The projection system of claim 11, wherein the light-absorbing medium layer comprises a light-absorbing dye, and a maximum thickness difference between different regions of the light-absorbing medium layer decreases with increasing of a proportion of the light-absorbing dye. ### Claim 15 (depends on 11) The projection system of claim 11, wherein the transparent medium layer is a transparent glue layer. ### Claim 16 (depends on 10) The projection system of claim 10, wherein the projection-reflecting layer comprises a total reflection layer and a light-absorbing layer stacked sequentially from the incident side of the projection light, wherein the light absorbing layer is capable of absorbing light; the total reflection layer comprises a microstructure layer, and the microstructure layer comprises a plurality of microstructure units; and the microstructure unit comprises a first plane at a lower side and a second plane at an upper side, wherein the first plane intersects the second plane, the plurality of microstructure units form a serrated structure, and total internal reflection of the projection light continuously happens on the first plane and the second plane. ### Claim 17 (depends on 16) The projection system of claim 16, wherein the microstructure layer comprises a rotationally symmetric structure, and a rotation center axis is perpendicular to a plane of the screen and is located below the screen. ### Claim 18 (depends on 10) The projection system of claim 10, wherein the projection-reflecting layer is a Fresnel reflection layer.