# US 2025/0093556 A1 · Light diffusion film, polarizer and display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0093556 A1 - Document ID: US20250093556A1 - Status: Published application - Kind: A1 - Application number: 18/384,877 - Filed: 2023-10-29 - Published: 2025-03-20 - Earliest claimed: 2023-09-20 - Assignees: Tcl China Star Optoelectronics Technology Co., Ltd. - Applicants: Tcl China Star Optoelectronics Technology Co., Ltd. - Inventors: Yue WANG - Web page: https://patentgrep.com/patent/US20250093556A1 ## CPC - G02B 5/0242: {by means of dispersed particles} - G02B 5/305: {including organic materials, e.g. polymeric layers} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An embodiment of the present application discloses a light diffusion film including a substrate and light diffusion particles dispersed in the substrate, wherein a mass fraction of the light diffusion particles in the substrate is less than 3%. According to the present application, by adding the light diffusion particles having a mass fraction less than 3% to the substrate of the light diffusion film, the viewing angle of the polarizer can be improved. ## Claims ### Claim 1 A light diffusion film, comprising: a substrate; and light diffusion particles dispersed in the substrate; wherein a mass fraction of the light diffusion particles in the substrate is less than 3%. ### Claim 2 (depends on 1) The light diffusion film of claim 1, wherein the light diffusion particles comprise first light diffusion particles; wherein the first light diffusion particles have a plurality of first cross-sections, each of the first cross-sections has a first circumcircle, a ratio of a length of a major axis of the first light diffusion particle to a diameter of a greatest first circumcircle of the first light diffusion particle is greater than or equal to 5, and less than 100, and the first cross-section is perpendicular to an extension direction of the major axis of the first light diffusion particle. ### Claim 3 (depends on 2) The light diffusion film of claim 2, wherein the first light diffusion particles are selected from at least one of a first subtype light diffusion particle, a second subtype light diffusion particle, a third subtype light diffusion particle, a fourth subtype light diffusion particle, and a fifth subtype light diffusion particle having different shapes from each other; wherein a variation value of diameters of first circumcircles of first cross-sections of the first subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the first subtype light diffusion particle; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the second subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the second subtype light diffusion particle; in a direction away from the middle portion of the second subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the second subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the second subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the third subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the third subtype light diffusion particle; in a direction away from the middle portion of the third subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the third subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the third subtype light diffusion particle gradually decrease; a first end portion of the fourth subtype light diffusion particle is connected to a second end portion of the fourth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections of the fourth subtype light diffusion particle gradually decrease in a direction from the first end portion of the fourth subtype light diffusion particle to the second end portion of the fourth subtype light diffusion particle; and a first end portion of the fifth subtype light diffusion particle is connected to a second end portion of the fifth subtype light diffusion particle, diameters of first circumcircles of first cross-sections at the first end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the second end portion of the fifth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections at the second end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the first end portion of the fifth subtype light diffusion particle. ### Claim 4 (depends on 3) The light diffusion film of claim 3, wherein the light diffusion particles further comprise second light diffusion particles; wherein the second light diffusion particles have a plurality of second cross-sections, each of the second cross-sections has a second circumcircle, a ratio of a length of a major axis of the second light diffusion particle to a diameter of a greatest second circumcircle is greater than or equal to 1, and less than 5, and the second cross-section is perpendicular to an extension direction of the major axis of the second light diffusion particle. ### Claim 5 (depends on 4) The light diffusion film of claim 4, wherein the second light diffusion particles are selected from at least one of a sixth subtype light diffusion particle, a seventh subtype light diffusion particle, an eighth subtype light diffusion particle, a ninth subtype light diffusion particle, and a tenth subtype light diffusion particle having different shapes from each other; wherein a variation value of diameters of second circumcircles of second cross-sections of the sixth subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the sixth subtype light diffusion particle; a first end portion of the seventh subtype light diffusion particle is connected to a second end portion of the seventh subtype light diffusion particle, diameters of second circumcircles of second sections at the first end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the second end portion of the seventh subtype light diffusion particle, and diameters of second circumcircles of second cross-sections at the second end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the first end portion of the seventh subtype light diffusion particle; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the eighth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the eighth subtype light diffusion particle; in a direction away from the middle portion of the eighth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the eighth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the eighth subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the ninth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the ninth subtype light diffusion particle; in a direction away from the middle portion of the ninth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the ninth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the ninth subtype light diffusion particle gradually decrease; and a first end portion of the tenth subtype light diffusion particle is connected to a second end portion of the tenth subtype light diffusion particle, and diameters of second circumcircles of second cross-sections of the tenth subtype light diffusion particle gradually decrease in a direction from the first end portion of the tenth subtype light diffusion particle to the second end portion of the tenth subtype light diffusion particle. ### Claim 6 (depends on 5) The light diffusion film of claim 5, wherein the first subtype light diffusion particle is selected from a rod-shaped particle, the second subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the third subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, the fourth subtype light diffusion particle is selected from a long cone-shaped particle, the fifth subtype light diffusion particle is selected from a bicone-shaped particle and/or an ellipsoid-shaped particle, the sixth subtype light diffusion particle is selected from a cubic particle or a cuboid-shaped particle, the seventh subtype light diffusion particle is selected from a spherical particle or an ellipsoid-shaped particle, the eighth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the ninth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, and the tenth subtype light diffusion particle is selected from a long cone-shaped particle. ### Claim 7 (depends on 3) The light diffusion film of claim 3, wherein a mass fraction of the fifth subtype light diffusion particles in the light diffusion particles is greater than or equal to 20%, and a mass fraction of the fifth subtype light diffusion particles in the light diffusion particles is less than or equal to 100%. ### Claim 8 (depends on 1) The light diffusion film of claim 1, wherein each of the light diffusion particles has an average particle size, a length of ta major axis of the light diffusion particle is greater than or equal to 20% of the average particle size of the light diffusion particle, and the length of the major axis of the light diffusion particle is less than or equal to 180% of the average particle size of the light diffusion particle. ### Claim 9 (depends on 1) The light diffusion film of claim 1, wherein the substrate comprises a first sub-substrate selected from at least one of an unmodified polyester, an unmodified acetate fiber, and/or a second sub-substrate selected from at least one of a modified polyester, a modified cellulose acetate; wherein a mass fraction of the first sub-substrate in the substrate is greater than or equal to 65%, and the mass fraction of the first sub-substrate in the substrate is less than or equal to 100%; and a mass fraction of the second sub-substrate in the substrate is greater than or equal to 0%, and the mass fraction of the second sub-substrate in the substrate is less than or equal to 35%. ### Claim 10 A polarizer, comprising a light diffusion film, wherein the light diffusion film comprises: a substrate; and light diffusion particles dispersed in the substrate; wherein a mass fraction of the light diffusion particles in the substrate is less than 3%. ### Claim 11 (depends on 10) The polarizer of claim 10, wherein the light diffusion particles comprise first light diffusion particles; wherein the first light diffusion particles have a plurality of first cross-sections, each of the first cross-sections has a first circumcircle, a ratio of a length of a major axis of the first light diffusion particle to a diameter of a greatest first circumcircle of the first light diffusion particle is greater than or equal to 5, and less than 100, and the first cross-section is perpendicular to an extension direction of the major axis of the first light diffusion particle; wherein the first light diffusion particles are selected from at least one of a first subtype light diffusion particle, a second subtype light diffusion particle, a third subtype light diffusion particle, a fourth subtype light diffusion particle, and a fifth subtype light diffusion particle having different shapes from each other; a variation value of diameters of first circumcircles of first cross-sections of the first subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the first subtype light diffusion particle; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the second subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the second subtype light diffusion particle; in a direction away from the middle portion of the second subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the second subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the second subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the third subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the third subtype light diffusion particle; in a direction away from the middle portion of the third subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the third subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the third subtype light diffusion particle gradually decrease; a first end portion of the fourth subtype light diffusion particle is connected to a second end portion of the fourth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections of the fourth subtype light diffusion particle gradually decrease in a direction from the first end portion of the fourth subtype light diffusion particle to the second end portion of the fourth subtype light diffusion particle; and a first end portion of the fifth subtype light diffusion particle is connected to a second end portion of the fifth subtype light diffusion particle, diameters of first circumcircles of first cross-sections at the first end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the second end portion of the fifth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections at the second end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the first end portion of the fifth subtype light diffusion particle. ### Claim 12 (depends on 11) The polarizer of claim 11, wherein the light diffusion particles further comprise second light diffusion particles; wherein the second light diffusion particles have a plurality of second cross-sections, each of the second cross-sections has a second circumcircle, a ratio of a length of a major axis of the second light diffusion particle to a diameter of a greatest second circumcircle is greater than or equal to 1, and less than 5, and the second cross-section is perpendicular to an extension direction of the major axis of the second light diffusion particle; wherein the second light diffusion particles are selected from at least one of a sixth subtype light diffusion particle, a seventh subtype light diffusion particle, an eighth subtype light diffusion particle, a ninth subtype light diffusion particle, and a tenth subtype light diffusion particle having different shapes from each other; wherein a variation value of diameters of second circumcircles of second cross-sections of the sixth subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the sixth subtype light diffusion particle; a first end portion of the seventh subtype light diffusion particle is connected to a second end portion of the seventh subtype light diffusion particle, diameters of second circumcircles of second sections at the first end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the second end portion of the seventh subtype light diffusion particle, and diameters of second circumcircles of second cross-sections at the second end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the first end portion of the seventh subtype light diffusion particle; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the eighth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the eighth subtype light diffusion particle; in a direction away from the middle portion of the eighth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the eighth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the eighth subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the ninth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the ninth subtype light diffusion particle; in a direction away from the middle portion of the ninth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the ninth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the ninth subtype light diffusion particle gradually decrease; and a first end portion of the tenth subtype light diffusion particle is connected to a second end portion of the tenth subtype light diffusion particle, and diameters of second circumcircles of second cross-sections of the tenth subtype light diffusion particle gradually decrease in a direction from the first end portion of the tenth subtype light diffusion particle to the second end portion of the tenth subtype light diffusion particle. ### Claim 13 (depends on 12) The polarizer of claim 12, wherein the first subtype light diffusion particle is selected from a rod-shaped particle, the second subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the third subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, the fourth subtype light diffusion particle is selected from a long cone-shaped particle, the fifth subtype light diffusion particle is selected from a bicone-shaped particle and/or an ellipsoid-shaped particle, the sixth subtype light diffusion particle is selected from a cubic particle or a cuboid-shaped particle, the seventh subtype light diffusion particle is selected from a spherical particle or an ellipsoid-shaped particle, the eighth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the ninth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, and the tenth subtype light diffusion particle is selected from a long cone-shaped particle. ### Claim 14 (depends on 11) The polarizer of claim 11, wherein a mass fraction of the fifth subtype light diffusion particles in the light diffusion particles is greater than or equal to 20%, and a mass fraction of the fifth subtype light diffusion particles in the light diffusion particles is less than or equal to 100%. ### Claim 15 (depends on 10) The polarizer of claim 10, wherein each of the light diffusion particles has an average particle size, a length of ta major axis of the light diffusion particle is greater than or equal to 20% of the average particle size of the light diffusion particle, and the length of the major axis of the light diffusion particle is less than or equal to 180% of the average particle size of the light diffusion particle. ### Claim 16 (depends on 10) The polarizer of claim 10, wherein the substrate comprises a first sub-substrate selected from at least one of an unmodified polyester, an unmodified acetate fiber, and/or a second sub-substrate selected from at least one of a modified polyester, a modified cellulose acetate; wherein a mass fraction of the first sub-substrate in the substrate is greater than or equal to 65%, and the mass fraction of the first sub-substrate in the substrate is less than or equal to 100%; and a mass fraction of the second sub-substrate in the substrate is greater than or equal to 0%, and the mass fraction of the second sub-substrate in the substrate is less than or equal to 35% ### Claim 17 A display device, comprising a polarizer, wherein the polarizer comprises a light diffusion film, and the light diffusion film comprises: a substrate; and light diffusion particles dispersed in the substrate; wherein a mass fraction of the light diffusion particles in the substrate is less than 3%. ### Claim 18 (depends on 17) The display device of claim 17, wherein the light diffusion particles comprise first light diffusion particles; wherein the first light diffusion particles have a plurality of first cross-sections, each of the first cross-sections has a first circumcircle, a ratio of a length of a major axis of the first light diffusion particle to a diameter of a greatest first circumcircle of the first light diffusion particle is greater than or equal to 5, and less than 100, and the first cross-section is perpendicular to an extension direction of the major axis of the first light diffusion particle; wherein the first light diffusion particles are selected from at least one of a first subtype light diffusion particle, a second subtype light diffusion particle, a third subtype light diffusion particle, a fourth subtype light diffusion particle, and a fifth subtype light diffusion particle having different shapes from each other; a variation value of diameters of first circumcircles of first cross-sections of the first subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the first subtype light diffusion particle; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the second subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the second subtype light diffusion particle; in a direction away from the middle portion of the second subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the second subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the second subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of first circumcircles of first cross-sections at a middle portion of the third subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the third subtype light diffusion particle; in a direction away from the middle portion of the third subtype light diffusion particle, a variation value of diameters of first circumcircles of first cross-sections at a first end portion of the third subtype light diffusion particle gradually decrease, and a variation value of diameters of first circumcircles of first cross-sections at a second end portion of the third subtype light diffusion particle gradually decrease; a first end portion of the fourth subtype light diffusion particle is connected to a second end portion of the fourth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections of the fourth subtype light diffusion particle gradually decrease in a direction from the first end portion of the fourth subtype light diffusion particle to the second end portion of the fourth subtype light diffusion particle; and a first end portion of the fifth subtype light diffusion particle is connected to a second end portion of the fifth subtype light diffusion particle, diameters of first circumcircles of first cross-sections at the first end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the second end portion of the fifth subtype light diffusion particle, and diameters of first circumcircles of first cross-sections at the second end portion of the fifth subtype light diffusion particle gradually decrease in a direction away from the first end portion of the fifth subtype light diffusion particle. ### Claim 19 (depends on 18) The display device of claim 18, wherein the light diffusion particles further comprise second light diffusion particles; wherein the second light diffusion particles have a plurality of second cross-sections, each of the second cross-sections has a second circumcircle, a ratio of a length of a major axis of the second light diffusion particle to a diameter of a greatest second circumcircle is greater than or equal to 1, and less than 5, and the second cross-section is perpendicular to an extension direction of the major axis of the second light diffusion particle; wherein the second light diffusion particles are selected from at least one of a sixth subtype light diffusion particle, a seventh subtype light diffusion particle, an eighth subtype light diffusion particle, a ninth subtype light diffusion particle, and a tenth subtype light diffusion particle having different shapes from each other; wherein a variation value of diameters of second circumcircles of second cross-sections of the sixth subtype light diffusion particle is less than or equal to 0.3 μm along an extension direction of a major axis of the sixth subtype light diffusion particle; a first end portion of the seventh subtype light diffusion particle is connected to a second end portion of the seventh subtype light diffusion particle, diameters of second circumcircles of second sections at the first end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the second end portion of the seventh subtype light diffusion particle, and diameters of second circumcircles of second cross-sections at the second end portion of the seventh subtype light diffusion particle gradually decrease in a direction away from the first end portion of the seventh subtype light diffusion particle; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the eighth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the eighth subtype light diffusion particle; in a direction away from the middle portion of the eighth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the eighth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the eighth subtype light diffusion particle is less than or equal to 1 μm; a variation value of diameters of second circumcircles of second cross-sections at a middle portion of the ninth subtype light diffusion particle is less than or equal to 1 μm along an extension direction of a major axis of the ninth subtype light diffusion particle; in a direction away from the middle portion of the ninth subtype light diffusion particle, a variation value of diameters of second circumcircles of second cross-sections at a first end portion of the ninth subtype light diffusion particle gradually decrease, and a variation value of diameters of second circumcircles of second cross-sections at a second end portion of the ninth subtype light diffusion particle gradually decrease; and a first end portion of the tenth subtype light diffusion particle is connected to a second end portion of the tenth subtype light diffusion particle, and diameters of second circumcircles of second cross-sections of the tenth subtype light diffusion particle gradually decrease in a direction from the first end portion of the tenth subtype light diffusion particle to the second end portion of the tenth subtype light diffusion particle. ### Claim 20 (depends on 19) The display device of claim 19, wherein the first subtype light diffusion particle is selected from a rod-shaped particle, the second subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the third subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, the fourth subtype light diffusion particle is selected from a long cone-shaped particle, the fifth subtype light diffusion particle is selected from a bicone-shaped particle and/or an ellipsoid-shaped particle, the sixth subtype light diffusion particle is selected from a cubic particle or a cuboid-shaped particle, the seventh subtype light diffusion particle is selected from a spherical particle or an ellipsoid-shaped particle, the eighth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to an end, the ninth subtype light diffusion particle is selected from an acicular particle having reduced diameters from middle to both ends, and the tenth subtype light diffusion particle is selected from a long cone-shaped particle.