# US 10,763,401 B2 · Backlight unit and display apparatus including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,763,401 B2 - Document ID: US10763401B2 - Status: Granted - Kind: B2 - Application number: 16/245,768 - Filed: 2019-01-11 - Published: 2019-07-18 - Granted: 2020-09-01 - Earliest claimed: 2018-01-12 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Hee-Kwang Song; Hyuk-Hwan Kim; Sanghyuck Yoon - Web page: https://patentgrep.com/patent/US10763401B2 ## CPC - H10H 20/8513: {having two or more wavelength conversion materials} - C09K 11/70: containing phosphorus - G02B 6/005: {provided by one optical element, or plurality thereof, placed on the light output side of the light guide} - G02B 6/0051: {Diffusing sheet or layer} - G02B 6/0053: {Prismatic sheet or layer; Brightness enhancement element, sheet or layer} - G02B 6/0055: {Reflecting element, sheet or layer} - G02B 6/0229: {characterised by nanostructures, i.e. structures of size less than 100 nm, e.g. quantum dots} - G02F 1/1336: {Illuminating devices} - H10H 20/8515: {not being in contact with the bodies} - G02B 6/0043: {provided on the surface of the light guide} - G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light} - G02F 2202/36: Micro- or nanomaterials - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - 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 ## Abstract A display apparatus includes a light source generating blue light. A display panel is configured to display an image. A light guide member is disposed below the display panel. A first light conversion layer is disposed between the light guide member and the display panel. The first light conversion layer includes a plurality of quantum dots. A low refractive layer is disposed between the light guide member and the first light conversion layer. The low refractive layer has a refractive index that is less than that of the light guide member. A second light conversion layer is disposed between the light source and the first light conversion layer and includes a plurality of fluoride-based or nitride-based phosphors. The first light conversion layer is configured to convert the blue light into green light, and the second light conversion layer is configured to convert the blue light into red light. ## Claims ### Claim 1 A display apparatus, comprising: a light source configured to generate blue light; a display panel configured to display an image; a light guide member disposed below the display panel; a first light conversion layer disposed between the light guide member and the display panel, the first light conversion layer comprising a plurality of quantum dots; a low refractive layer disposed between the light guide member and the first light conversion layer, the low refractive layer having a refractive index that is less than that of the light guide member; an optical filter layer disposed between the low refractive layer and the first light conversion layer, the optical filter layer configured to reflect green light and to transmit red light and blue light; and a second light conversion layer disposed between the light source and the first light conversion layer and comprising a plurality of KSF phosphors, wherein the first light conversion layer is configured to convert the blue light into the green light, and wherein the second light conversion layer is configured to convert the blue light into the red light. ### Claim 2 (depends on 1) The display apparatus of claim 1, wherein the second light conversion layer is disposed between the light source and the light guide member. ### Claim 3 (depends on 2) The display apparatus of claim 2, wherein the light source is disposed adjacent to at least one side surface of the light guide member. ### Claim 4 (depends on 1) The display apparatus of claim 1, further comprising a first protective layer disposed between the first light conversion layer and the display panel, the first protective layer covering the first light conversion layer. ### Claim 5 (depends on 1) The display apparatus of claim 1, wherein the optical filter layer comprises: a plurality of first insulation films each of which having a first refractive index; and a plurality of second insulation films each of which having a second refractive index that is less than the first refractive index, and wherein the plurality of first insulation films and the plurality of second insulation films are alternately laminated. ### Claim 6 (depends on 1) The display apparatus of claim 1, wherein the first light conversion layer is coated on the low refractive layer. ### Claim 7 (depends on 1) The display apparatus of claim 1, wherein the second light conversion layer is disposed between the low refractive layer and the first light conversion layer. ### Claim 8 (depends on 7) The display apparatus of claim 7, further comprising a second protective layer disposed between the first light conversion layer and the low refractive layer and separating the first light conversion layer and the low refractive layer from each other. ### Claim 9 (depends on 1) The display apparatus of claim 1, wherein a ratio of an intensity of a peak wavelength of the red light transmitted through the second light conversion layer with respect to an intensity of a peak wavelength of the blue light provided from the light source is 0.2 or less. ### Claim 10 (depends on 1) The display apparatus of claim 1, wherein the first light conversion layer further comprises a plurality of diffusion particles configured to diffuse incident light. ### Claim 11 (depends on 1) The display apparatus of claim 1, wherein a central area and a peripheral area surrounding the central area are defined on a top surface of the light guide member, wherein the central area of the light guide member contacts a bottom surface of the low refractive layer, and wherein at least a portion of the peripheral area of the light guide member is coupled to an edge of a bottom surface of the display panel. ### Claim 12 (depends on 11) The display apparatus of claim 11, wherein the peripheral area comprises a light incident part adjacent to the light source, and wherein the peripheral area, except for the light incident part, is coupled to the edge of the bottom surface of the display panel. ### Claim 13 (depends on 11) The display apparatus of claim 11 wherein the light guide member, the low refractive layer, the first light conversion layer, and the display panel are part of a single integral unit. ### Claim 14 (depends on 1) The display apparatus of claim 1, wherein the first light conversion layer has a thickness within a range of 5 μm to 30 μm, inclusive. ### Claim 15 (depends on 1) The display apparatus of claim 1, wherein a content of a quantum dot per unit volume of the first light conversion layer is within a range of 5% to 30%, inclusive. ### Claim 16 (depends on 1) The display apparatus of claim 1, wherein the low refractive layer has a thickness of 0.5 μm. ### Claim 17 A display apparatus, comprising: a display panel configured to display an image; a light guide member disposed below the display panel, the light guide member comprising a light incident surface defined on at least one side surface thereof; a light source disposed adjacent to the light incident surface, the light source configured to generate blue light; a first light conversion layer disposed between the light guide member and the display panel, the first light conversion layer comprising a plurality of quantum dots; a low refractive layer disposed between the light guide member and the first light conversion layer, the low refractive layer having a refractive index less than that of the light guide member; a first protective layer disposed between the first light conversion layer and the display panel, the first protective layer covering the first light conversion layer, and a second light conversion layer disposed between the low refractive index layer and the first light conversion layer, the second light conversion layer comprising a plurality of KSF phosphors, wherein the first light conversion layer is configured to convert the blue light into green light, wherein the second light conversion layer is configured to convert the blue light into red light. ### Claim 18 (depends on 17) The display apparatus of claim 17, wherein a ratio of an intensity of a peak wavelength of the red light transmitted through the second light conversion layer with respect to an intensity of a peak wavelength of the blue light provided from the light source is 0.2 or less. ### Claim 19 A backlight unit, comprising: a light guide member comprising a light incident surface defined on at least one side surface thereof; a light source disposed adjacent to the light incident surface, the light source configured to generate blue light; a first light conversion layer disposed on the light guide member, the first light conversion layer comprising a plurality of quantum dots; a low refractive layer disposed between the first light conversion layer and the light guide member, the low refractive layer having a refractive index less than that of each of the first light conversion layer and the light guide member; and a second light conversion layer disposed between the first light conversion layer and the light source, the second light conversion layer comprising a plurality of KSF phosphors (K2SiF6:Mn4+), wherein the first light conversion layer is configured to convert the blue light into green light, wherein the second light conversion layer is configured to convert the blue light into red light, wherein a central area and a peripheral area surrounding the central area are defined on a top surface of the light guide member, wherein the central area of the light guide member contacts a bottom surface of the low refractive layer, and wherein at least a portion of the peripheral area of the light guide member is coupled to an edge of a bottom surface of a display panel.