# US 11,906,842 B2 · Optical film for back light unit and back light unit including same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,906,842 B2 - Document ID: US11906842B2 - Status: Granted - Kind: B2 - Application number: 17/985,839 - Filed: 2022-11-12 - Published: 2023-03-16 - Granted: 2024-02-20 - Earliest claimed: 2020-01-24 - Assignees: BrightView Technologies, Inc. - Applicants: BrightView Technologies, Inc. - Inventors: Jennifer Aspell; Thomas A. Rinehart; Bing Shen; Kenneth L. Walker - Web page: https://patentgrep.com/patent/US11906842B2 ## CPC - G02F 1/133603: {with LEDs} - G02B 5/0215: {the surface having a regular structure} - G02B 5/0231: {the surface having microprismatic or micropyramidal shape (macroscopic prism arrays G02B5/045)} - G02B 5/0263: {with positional variation of the diffusing properties, e.g. gradient or patterned diffuser} - G02B 5/0278: {used in transmission} - G02F 1/133607: {the light controlling member including light directing or refracting elements, e.g. prisms or lenses} - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical film for a back light unit that includes an array of light emitting diodes. The optical film includes a substrate, and a plurality of regions of spatially modulated microstructures on at least one side of the substrate. The spatially modulated microstructures have different sizes and/or shapes configured to create a gradient structure within each region. The gradient structure within each region is constructed and arranged to cause more spreading of light when positioned directly above an individual light emitting diode and less spreading of light at locations not directly above an individual light emitting diode. Within the back light unit, the gradient structure converts light beams emitted by the respective light emitting diode at different angles into a more uniform and higher on-axis luminance upon exiting the back light unit. ## Claims ### Claim 1 An optical film for a back light unit comprising an array of light emitting diodes, the optical film comprising: a) a substrate; and b) a plurality of first regions of spatially modulated microstructures on at least one side of the substrate, the spatially modulated microstructures having different sizes configured to create a gradient structure within each first region, each of the plurality of first regions being substantially circular in shape in plan-view, wherein a center of at least one of the plurality of first regions is configured to be positioned directly over a light emitting diode comprising the array of light emitting diodes, the gradient structure within each first region being constructed and arranged to cause a first level of spreading of light when positioned directly above an individual light emitting diode and a second level of spreading of light at locations not directly above an individual light emitting diode, the second level being less that the first level; c) a plurality of second regions of spatially modulated microstructures on the at least one side of the substrate; and d) a plurality of third regions of spatially modulated microstructures on a side of the substrate that is different from the at least one side of the substrate. ### Claim 2 (depends on 1) The optical film according to claim 1, wherein the spatially modulated microstructures comprise a plurality of elongated prisms. ### Claim 3 (depends on 1) The optical film according to claim 1, wherein the spatially modulated microstructures comprise a plurality of three-sided pyramids. ### Claim 4 (depends on 1) The optical film according to claim 1, wherein the spatially modulated microstructures comprise a plurality of cones. ### Claim 5 (depends on 1) The optical film according to claim 1, wherein the spatially modulated microstructures comprise a first plurality of parallel prisms and a second plurality of parallel prisms. ### Claim 6 (depends on 5) The optical film according to claim 5, wherein the first plurality of parallel prisms and the second plurality of parallel prisms have apexes having substantially the same angles. ### Claim 7 (depends on 6) The optical film according to claim 6, wherein the angles are about 90°. ### Claim 8 (depends on 1) The optical film according to claim 1, wherein the plurality of first regions of spatially modulated microstructures are configured to provide the optical film with a lattice-type structure. ### Claim 9 (depends on 1) The optical film according to claim 1, wherein the array of light-emitting diodes is an array of mini-light emitting diodes comprising a plurality of mini-light emitting diodes; and, wherein the center of at least one of the plurality of first regions is configured to be positioned directly over a mini-light emitting diode comprising the array of mini-light emitting diodes. ### Claim 10 (depends on 1) The optical film according to claim 1, wherein at least one of the plurality of second regions of spatially modulated microstructures are arranged to be located with centers positioned in between two light emitting diodes comprising the array of light emitting diodes. ### Claim 11 (depends on 1) The optical film according to claim 1, wherein the plurality of third regions is constructed and arranged to cause a third level of spreading of light, the third level being less than the first level and greater than the second level. ### Claim 12 (depends on 11) The optical film according to claim 11, wherein each of the plurality of third regions comprises a gradient comprising a mixture prism segments configured to provide a gradient that transitions between the microstructures of the plurality of first regions and the microstructures of the plurality of second regions. ### Claim 13 An optical film for a back light unit comprising an array of light emitting diodes, the optical film comprising: a) a substrate; and b) a plurality of first regions of spatially modulated microstructures on at least one side of the substrate, the spatially modulated microstructures having different shapes configured to create a gradient structure within each first region, each of the plurality of first regions being substantially circular in shape in plan-view, wherein a center of at least one of the plurality of first regions is configured to be positioned directly over a light emitting diode comprising the array of light emitting diodes, the gradient structure within each first region being constructed and arranged to cause a first level of spreading of light when positioned directly above an individual light emitting diode and a second level of spreading of light at locations not directly above an individual light emitting diode, the second level being less that the first level; c) a plurality of second regions of spatially modulated microstructures on the at least one side of the substrate; and d) a plurality of third regions of spatially modulated microstructures on a side of the substrate that is different from the at least one side of the substrate. ### Claim 14 (depends on 13) The optical film according to claim 13, wherein the spatially modulated microstructures comprise a plurality of elongated prisms. ### Claim 15 (depends on 13) The optical film according to claim 13, wherein the spatially modulated microstructures comprise a plurality of three-sided pyramids. ### Claim 16 (depends on 13) The optical film according to claim 13, wherein the spatially modulated microstructures comprise a plurality of cones. ### Claim 17 (depends on 13) The optical film according to claim 13, wherein the spatially modulated microstructures comprise a first plurality of parallel prisms and a second plurality of parallel prisms. ### Claim 18 (depends on 17) The optical film according to claim 17, wherein the first plurality of parallel prisms and the second plurality of parallel prisms have apexes having substantially the same angles. ### Claim 19 (depends on 18) The optical film according to claim 18, wherein the angles are about 90°. ### Claim 20 (depends on 13) The optical film according to claim 13, wherein the plurality of first regions of spatially modulated microstructures are configured to provide the optical film with a lattice-type structure. ### Claim 21 (depends on 13) The optical film according to claim 13, wherein the array of light-emitting diodes is an array of mini-light emitting diodes comprising a plurality of mini-light emitting diodes; and, wherein the center of at least one of the plurality of first regions is configured to be positioned directly over a mini-light emitting diode comprising the array of mini-light emitting diodes. ### Claim 22 (depends on 13) The optical film according to claim 13 wherein at least one of the plurality of second regions of spatially modulated microstructures are arranged to be located with centers positioned in between two light emitting diodes comprising the array of light emitting diodes. ### Claim 23 (depends on 13) The optical film according to claim 13, wherein the plurality of third regions is constructed and arranged to cause a third level of spreading of light, the third level being less than the first level and greater than the second level. ### Claim 24 (depends on 23) The optical film according to claim 23, wherein each of the plurality of third regions comprises a gradient comprising a mixture prism segments configured to provide a gradient that transitions between the microstructures of the plurality of first regions and the microstructures of the plurality of second regions. ### Claim 25 A back light unit comprising: a) an array of light emitting diodes; and b) an optical film positioned above the array of light emitting diodes, the optical film comprising: i) a substrate; ii) a plurality of first regions of spatially modulated microstructures on at least one side of the substrate, the spatially modulated microstructures having different sizes and/or shapes configured to create a gradient structure within each first region, each of the plurality of first regions being substantially circular in shape in plan-view, wherein a center of at least one of the plurality of first regions is positioned directly over a light emitting diode comprising the array of light emitting diodes, the gradient structure within each first region being constructed and arranged to cause a first level of spreading of light when positioned directly above an individual light emitting diode and a second level of spreading of light at locations not directly above an individual light emitting diode, the second level being less that the first level; iii) a plurality of second regions of spatially modulated microstructures on the at least one side of the substrate; and iv) a plurality of third regions of spatially modulated microstructures on a side of the substrate that is different from the at least one side of the substrate. ### Claim 26 (depends on 25) The back light unit according to claim 25, wherein the array of light emitting diodes comprises an array of mini LEDs.