# US 11,994,767 B2 · Lighting device using wavelength conversion sheet, and display device using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,767 B2 - Document ID: US11994767B2 - Status: Granted - Kind: B2 - Application number: 18/127,520 - Filed: 2023-03-28 - Published: 2023-10-05 - Granted: 2024-05-28 - Earliest claimed: 2022-03-30 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: Hirotoshi Yasunaga; Takeshi Masuda; Hisashi Watanabe; Youzou Kyoukane - Web page: https://patentgrep.com/patent/US11994767B2 ## CPC - G02F 1/133603: {with LEDs} - G02F 1/133607: {the light controlling member including light directing or refracting elements, e.g. prisms or lenses} - G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light} - H10H 20/8513: {having two or more wavelength conversion materials} - H10H 20/8514: {characterised by their shape, e.g. plate or foil} - H10H 20/8515: {not being in contact with the bodies} - H10W 90/00: Package configurations - G02F 1/133601: {for spatial active dimming} - 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 - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A lighting device includes a plurality of light sources arranged side by side in a plane and a wavelength conversion sheet arranged to face a light emitting surface of each of the light sources and converting a wavelength of light from the light sources, in which the wavelength conversion sheet includes a base material having transparency, and a wavelength conversion layer in which a plurality of protrusions containing a wavelength conversion material and having a spherical surface are arranged side by side without gaps on a principal surface of the base material opposite to the light sources. ## Claims ### Claim 1 A lighting device comprising: a plurality of light sources arranged side by side in a plane; and a wavelength conversion sheet arranged to face a light emitting surface of each of the plurality of light sources and converting a wavelength of light from the plurality of light sources, wherein the wavelength conversion sheet includes: a base material having transparency, and a wavelength conversion layer, in which a plurality of protrusions containing a wavelength conversion material and having a spherical surface, is arranged side by side without gaps on a principal surface of the base material opposite the plurality of light sources, the wavelength conversion layer is provided on each of a pair of principal surfaces of the base material, and centers of the plurality of protrusions in a plan view are arranged at different positions in the wavelength conversion layer provided on one of the pair of principal surfaces and the wavelength conversion layer provided on another one of the pair of principal surfaces. ### Claim 2 (depends on 1) The lighting device according to claim 1, further comprising: a light source substrate having a mounting surface on which the plurality of light sources is arranged side by side, wherein the mounting surface is divided into a plurality of division regions each having a size and containing at least one of the plurality of light sources, the plurality of light sources is configured to be independently driven for each of the plurality of division regions, and a center-to-center distance between adjacent protrusions of the plurality of protrusions is equal to or less than a center-to-center distance between adjacent division regions of the plurality of division regions. ### Claim 3 (depends on 2) The lighting device according to claim 2, wherein each of the plurality of division regions has a rectangular shape and is divided such that one of the plurality of light sources is included in a central portion of each of the plurality of division regions, and the center-to-center distance between the adjacent division regions is substantially equal to a center-to-center distance between adjacent light sources of the plurality of light sources. ### Claim 4 (depends on 1) The lighting device according to claim 1, wherein a thickness of the base material is 20 μm or more and 300 μm or less. ### Claim 5 (depends on 1) The lighting device according to claim 1, wherein the wavelength conversion sheet further includes a low-refractive-index layer, having a refractive index lower than a refractive index of each of the base material and the wavelength conversion layer, between the base material and the wavelength conversion layer. ### Claim 6 (depends on 1) The lighting device according to claim 1, wherein each of the plurality of protrusions has a semi-elliptical section and a polygonal shape in the plan view. ### Claim 7 (depends on 1) A lighting device comprising: according to claim 1, a plurality of light sources arranged side by side in a plane; and a wavelength conversion sheet arranged to face a light emitting surface of each of the plurality of light sources and converting a wavelength of light from the plurality of light sources, wherein the wavelength conversion sheet includes: a base material having transparency, and a wavelength conversion layer, in which a plurality of protrusions containing a wavelength conversion material and having a spherical surface, is arranged side by side without gaps on a principal surface of the base material opposite the plurality of light sources, and each of the plurality of light sources is a monochromatic light emitting type light emitting diode (LED) having an area of the light emitting surface of 0.01 mm2 or more and 1.0 mm2 or less, and the wavelength conversion sheet is a phosphor sheet having a dispersed and blended phosphor material. ### Claim 8 (depends on 1) A display device comprising: the lighting device according to claim 1; and a display panel that performs display using light from the lighting device. ### Claim 9 (depends on 8) The display device according to claim 8, wherein the display panel is a liquid crystal panel having a liquid crystal layer.