# US 11,307,346 B2 · Backlight unit and display apparatus comprising same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,346 B2 - Document ID: US11307346B2 - Status: Granted - Kind: B2 - Application number: 17/075,318 - Filed: 2020-10-20 - Published: 2021-05-20 - Granted: 2022-04-19 - Earliest claimed: 2019-11-20 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Kyehoon Lee - Web page: https://patentgrep.com/patent/US11307346B2 ## CPC - G02B 6/005: {provided by one optical element, or plurality thereof, placed on the light output side of the light guide} - G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light} - G02B 26/005: {based on electrowetting} - G02F 1/13306: {Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence)} - G02F 1/133624: {characterised by their spectral emissions} - G02F 1/137: characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering - G02F 1/1334: based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals - G02F 1/133621: {providing coloured light (G02F1/133617, G02F1/133533 take precedence)} - G02F 1/13475: {in which at least one liquid crystal cell or layer is doped with a pleochroic dye, e.g. GH-LC cell (G02F1/13476 takes precedence)} - G02F 1/13718: {based on a change of the texture state of a cholesteric liquid crystal} - G02F 2201/501: Blocking layers, e.g. against migration of ions - G02F 2203/03: scattering - G02F 2203/62: Switchable arrangements whereby the element being usually not switchable - 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 Provided are a backlight unit and a display apparatus including the same. The backlight unit includes: a light guide plate configured to diffuse and transmit light that is incident on the light guide plate; and a white light emitting member configured to convert incident light transmitted by the light guide plate to white light having a color temperature that is adjusted according to a degree of conversion of the incident light into light of a specific color based on application of an electrical signal to the white light emitting member, and to emit the white light. ## Claims ### Claim 1 A backlight unit comprising: a light guide plate configured to diffuse and transmit first light that is incident on the light guide plate; and a white light emitting member configured to convert incident first light transmitted by the light guide plate to white light based on application of an electrical signal to the white light emitting member, and to output the white light, the white light comprising a part of the first light, second light and third light having different wavelengths from each other, wherein the white light emitting member comprises a single base layer comprising a deformable polymer material in which a plurality of first color conversion particles configured to convert one part of the incident first light into the second light, a plurality of second color conversion particles configured to convert another part of the incident first light into the third light, and a plurality of electro-optical particles are interspersed, and wherein the plurality of electro-optical particles are configured to adjust an amount of the incident first light converted into the second light and the third light by changing optical properties of the plurality of electro-optical particles based on the electrical signal to adjust a color temperature of the white light, and wherein the color temperature of the white light is adjusted by adjusting a density of the plurality of color conversion particles according to the expansion and contraction of the deformable polymer material based on the application of the electrical signal. ### Claim 2 (depends on 1) The backlight unit of claim 1, wherein the white light emitting member is configured to convert the incident first light to white light having a first color temperature when the electrical signal is applied to the white light emitting member, and to convert the incident first light to white light having a second color temperature that is different from the first color temperature when the electrical signal is not applied to the white light emitting member. ### Claim 3 (depends on 2) The backlight unit of claim 2, wherein the first color temperature is higher than the second color temperature. ### Claim 4 (depends on 1) The backlight unit of claim 1, further comprising a first electrode and a second electrode that are positioned apart from each other with the white light emitting member positioned between the first electrode and the second electrode, the first electrode and the second electrode being configured to apply the electrical signal to the white light emitting member. ### Claim 5 (depends on 1) The backlight unit of claim 1, wherein at least one of the plurality of electro-optical particles comprises at least one of liquid crystal and an electrowetting material. ### Claim 6 (depends on 5) The backlight unit of claim 5, wherein the liquid crystal comprises at least one of polymer dispersed liquid crystal (PDLC), polymer network liquid crystal (PNLC), cholesteric liquid crystal, or smectic liquid crystal. ### Claim 7 (depends on 1) The backlight unit of claim 1, wherein at least one color conversion particle of the plurality of first color conversion particles and the plurality of second color conversion particles comprises quantum dots. ### Claim 8 (depends on 1) The backlight unit of claim 1, wherein the plurality of first color conversion particles are configured to convert blue light into red light; and the plurality of second color conversion particles are configured to convert the blue light into green light. ### Claim 9 (depends on 1) The backlight unit of claim 1, wherein at least one color conversion particle of the plurality of first color conversion particles and the plurality of second color conversion particles converts at least one of blue light or green light into red light. ### Claim 10 A backlight unit comprising: a light guide plate configured to diffuse and transmit light that is incident on the light guide plate; and a white light emitting member configured to convert incident light transmitted by the light guide plate to white light based on application of an electrical signal to the white light emitting member, and to output the white light, wherein the white light emitting member comprises a base layer in which a plurality of color conversion particles and a plurality of electro-optical particles are interspersed, wherein the plurality of color conversion particles are configured to convert the incident light into light of a specific color, wherein the plurality of electro-optical particles are configured to adjust an amount of the incident light converted into the light of the specific color by changing optical properties of the plurality of electro-optical particles based on the electrical signal to adjust a temperature of the white light, and wherein the base layer comprises: a first base layer in which the plurality of electro-optical particles are dispersed; and a second base layer in which the plurality of color conversion particles are dispersed, and wherein the first base layer and the second base layer are sequentially arranged such that the first base layer is positioned between the light guide plate and the second base layer. ### Claim 11 A backlight unit comprising: a light guide plate configured to diffuse and transmit light that is incident on the light guide plate; and a white light emitting member configured to convert incident light transmitted by the light guide plate to white light based on application of an electrical signal to the white light emitting member, and to output the white light, wherein the white light emitting member comprises a plurality of color conversion particles configured to convert the incident light to the white light and a deformable polymer material configured to expand and contract according to the application of the electrical signal, and wherein a color temperature of the white light is adjusted by adjusting a density of the plurality of color conversion particles according to the expansion and contraction of the deformable polymer material based on the application of the electrical signal. ### Claim 12 A display apparatus comprising: a light source configured to emit light; a light guide plate configured to diffuse and transmit first light that is emitted from the light source; a white light emitting member configured to convert incident first light transmitted by the light guide plate to white light based on application of an electrical signal to the white light emitting member, and to output the white light, the white light comprising a part of the first light, second light, and third light having different wavelengths from each other; and a display panel configured to generate an image using the white light output by the white light emitting member, wherein the white light emitting member comprises a single base layer comprising a deformable polymer material in which a plurality of first color conversion particles configured to convert one part of the incident first light into the second light, a plurality of second color conversion particles configured to convert another part of the incident first light into the third light, and a plurality of electro-optical particles are interspersed, and wherein the plurality of electro-optical particles are configured to adjust an amount of the incident first light converted into the light of the second light and the third light by changing optical properties of the plurality of electro-optical particles based on the electrical signal, and wherein the color temperature of the white light is adjusted by adjusting a density of the plurality of color conversion particles according to the expansion and contraction of the deformable polymer material based on the application of the electrical signal. ### Claim 13 (depends on 12) The display apparatus of claim 12, wherein at least one color conversion particle of the plurality of first color conversion particles and the plurality of second color conversion particles comprises quantum dots. ### Claim 14 (depends on 12) The display apparatus of claim 12, wherein at least one of the plurality of electro-optical particles comprises at least one of polymer dispersed liquid crystal (PDLC), polymer network liquid crystal (PNLC), cholesteric liquid crystal, or smectic liquid crystal. ### Claim 15 (depends on 12) The display apparatus of claim 12, wherein the display panel comprises a liquid crystal display panel.