# US 11,994,269 B2 · Backlight unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,269 B2 - Document ID: US11994269B2 - Status: Granted - Kind: B2 - Application number: 18/178,856 - Filed: 2023-03-06 - Published: 2023-07-06 - Granted: 2024-05-28 - Earliest claimed: 2017-12-08 - Assignees: Seoul Semiconductor Co., Ltd. - Applicants: Seoul Semiconductor Co., Ltd. - Inventors: Chung Hoon Lee - Web page: https://patentgrep.com/patent/US11994269B2 ## CPC - F21V 13/08: the elements being filters or photoluminescent elements and reflectors - F21V 3/12: the coatings comprising photoluminescent substances - F21V 7/04: Optical design - F21V 7/24: characterised by the material - F21V 9/30: Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) - G02B 6/0055: {Reflecting element, sheet or layer} - G02B 6/0073: {Light emitting diode [LED]} - G02F 1/133603: {with LEDs} - G02F 1/133605: {including specially adapted reflectors} - G02F 1/133606: {including a specially adapted diffusing, scattering or light controlling members} - H10H 20/8514: {characterised by their shape, e.g. plate or foil} - H10H 20/856: Reflecting means - H10W 90/00: Package configurations - F21Y 2105/16: square or rectangular, e.g. for light panels - F21Y 2115/10: Light-emitting diodes [LED] - G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light} - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/815: having stress relaxation structures, e.g. buffer layers - H10H 20/816: having carrier transport control structures, e.g. highly-doped semiconductor layers or current-blocking structures - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/833: Transparent materials - H10H 20/841: Reflective coatings, e.g. dielectric Bragg reflectors - H10H 20/8512: {Wavelength conversion materials} - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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 - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## Abstract The present invention relates to a backlight unit for use in a display device. The backlight unit includes a circuit board, at least one light-emitting diode chip mounted on the circuit board, a plurality of reflection members arranged on the upper part of the light-emitting diode chip, and a light diffusing member. The light diffusing member has an incident surface on which light enters and an emitting surface from which light is emitted. The light diffusing member is arranged on the upper part of the circuit board. The plurality of reflection members are stacked on each other and reflect a part of light emitted from the upper surface of the light-emitting diode chip. ## Claims ### Claim 1 A backlight unit, comprising: a circuit board; a light emitting diode disposed on the circuit board and configured to emit a primary light; a reflector disposed on the light emitting diode; and a wavelength converter disposed on the circuit board and configured to convert the primary light, wherein the light emitting diode comprises: a substrate; a light emitting layer disposed on the substrate; a first electrode pad electrically connected to a first conductivity type semiconductor layer of the light emitting layer; a second electrode pad electrically connected to a second conductivity type semiconductor layer of the light emitting layer; and a reflective layer disposed on the substrate and configured to reflect the primary light toward the wavelength converter, wherein the wavelength converter covers a side and an upper surface of the light emitting diode, and wherein the reflector covers an upper surface of the wavelength converter and a lowermost layer of the reflector contacts the upper surface of the wavelength converter. ### Claim 2 (depends on 1) The backlight unit of claim 1, wherein the lowermost layer of the reflector entirely covers the upper surface of the wavelength converter. ### Claim 3 (depends on 2) The backlight unit of claim 2, wherein the lowermost layer of the reflector entirely covers an upper surface of the light emitting diode. ### Claim 4 (depends on 1) The backlight unit of claim 1, wherein the wavelength converter is disposed between the circuit board and the reflector and surrounds the light emitting diode. ### Claim 5 (depends on 1) The backlight unit of claim 1, wherein the wavelength converter comprises a Mn4+-activated phosphors, which is fluoride compound K2SiF6. ### Claim 6 (depends on 1) The backlight unit of claim 1, wherein the reflective layer is a distributed bragg reflector (DBR) comprising at least one set of two different layers, each layer including SiO2, TiO2, SiN, or TiN, and wherein if the DBR comprises two sets of two different layers, a first set of two different layers is stacked above a second set of two different layers. ### Claim 7 (depends on 1) The backlight unit of claim 1, further comprising a light guide disposed on the circuit board and having an inclined portion. ### Claim 8 (depends on 7) The backlight unit of claim 7, wherein the light guide is structured to provide an increased light incident area as compared to a case without the inclined portion. ### Claim 9 A backlight unit comprising: a circuit board; a light emitting diode disposed on the circuit board and configured to emit a primary light; a reflector disposed on the circuit board; and a wavelength converter disposed on the circuit board and configured to convert the primary light, wherein the light emitting diode comprises: a substrate; a light emitting layer disposed on the substrate; a first electrode pad electrically connected to a first conductivity type semiconductor layer of the light emitting layer; a second electrode pad electrically connected to a second conductivity type semiconductor layer of the light emitting layer; and a reflective layer disposed on the substrate and configured to reflect the primary light toward the wavelength converter, wherein the wavelength converter covers a side and an upper surface of the light emitting diode, wherein the reflector covers a side of the wavelength converter and the light emitting diode and a surface of the reflector contacts a surface of the wavelength converter, and wherein the wavelength converter comprises a Mn 4+-activated phosphors, which is fluoride compound K2SiF6. ### Claim 10 (depends on 9) The backlight unit of claim 9, wherein the surface of the reflector entirely covers the surface of the wavelength converter. ### Claim 11 (depends on 10) The backlight unit of claim 10, wherein the surface of the reflector entirely covers the side of the light emitting diode. ### Claim 12 (depends on 9) The backlight unit of claim 9, wherein the wavelength converter is disposed between the circuit board and the reflector and surrounds the light emitting diode. ### Claim 13 (depends on 9) The backlight unit of claim 9, wherein the reflective layer is a distributed bragg reflector (DBR) comprising at least one set of two different layers, each layer including SiO2, TiO2, SiN, or TiN, and wherein if the DBR comprises two sets of two different layers, a first set of two different layers is stacked above a second set of two different layers. ### Claim 14 (depends on 9) The backlight unit of claim 9, further comprising a light guide disposed on the circuit board and having an inclined portion. ### Claim 15 (depends on 14) The backlight unit of claim 14, wherein the light guide is structured to provide an increased light incident area as compared to a case without the inclined portion. ### Claim 16 A light emitting module, comprising: a circuit board; a light emitting diode disposed on the circuit board and configured to emit a primary light; a reflector disposed on the light emitting diode; a light guide disposed on the circuit board and having an opening region; and a sealer disposed on the light emitting diode, wherein the light emitting diode comprises: a substrate; a light emitting layer disposed on the substrate; a first electrode pad electrically connected to a first conductivity type semiconductor layer of the light emitting layer; and a second electrode pad electrically connected to a second conductivity type semiconductor layer of the light emitting layer; wherein the light guide has an inclined region and is structured to provide an increased light incident area as compared to a case without the inclined region, and wherein the sealer is disposed in the opening region. ### Claim 17 (depends on 16) The light emitting module of claim 16, wherein the sealer contacts the light guide and covers the light emitting diode. ### Claim 18 (depends on 16) The light emitting module of claim 16, wherein the light guide surrounds a side of the light emitting diode. ### Claim 19 (depends on 18) The light emitting module of claim 18, wherein the inclined region of the light guide is inclined toward the light emitting diode from a lower region to an upper region thereof. ### Claim 20 (depends on 16) The light emitting module of claim 16, wherein the opening region of the light guide has a width decreasing in a direction away from the circuit board.