# US 11,442,304 B2 · Electronic device and liquid crystal display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,304 B2 - Document ID: US11442304B2 - Status: Granted - Kind: B2 - Application number: 17/305,822 - Filed: 2021-07-15 - Published: 2021-11-04 - Granted: 2022-09-13 - Earliest claimed: 2019-01-25 - Assignees: Japan Display Inc. - Applicants: Japan Display Inc. - Inventors: Mitsutaka Okita - Web page: https://patentgrep.com/patent/US11442304B2 ## CPC - G02F 1/13312: {Circuits comprising photodetectors for purposes other than feedback} - G02F 1/13338: {Input devices, e.g. touch panels} - G02F 1/1334: based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals - G02F 1/133504: {Diffusing, scattering, diffracting elements (associated to illuminating devices G02F1/133606)} - G02F 1/133531: {characterised by the arrangement of polariser or analyser axes} - G02F 1/133536: {Reflective polarizers (G02F1/13362 takes precedence)} - 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 An electronic device includes a liquid crystal display panel having a display region disposed with a plurality of pixels, an image sensor disposed on the back side of the liquid crystal display panel and imaging the front direction through the liquid crystal display panel, and a lighting unit disposed between the liquid crystal display panel and the image sensor. The image sensor is disposed in a region overlapping the display region, and the lighting unit includes an optical modulation element disposed to overlap the display region and a light source for lighting the optical modulation element. ## Claims ### Claim 1 An electronic device, comprising: a liquid crystal display panel having a display region disposed with a plurality of pixels; an image sensor disposed on a back side of the liquid crystal display panel and imaging a front direction through the liquid crystal display panel; and a lighting unit disposed between the liquid crystal display panel and the image sensor, a first reflective polarizing plate disposed on the lighting unit side of the liquid crystal display panel; and a second reflective polarizing plate disposed between the image sensor and an optical modulation element, wherein the image sensor is disposed in a region overlapping the display region, and the lighting unit includes the optical modulation element disposed to overlap with the display region and a light source for lighting the optical modulation element. ### Claim 2 (depends on 1) The electronic device according to claim 1, wherein the optical modulation element is configured to have a scattering state for scattering light emitted from the light source in the direction of the liquid crystal display panel, and a transmission state for making a region overlapping the image sensor transparent and maintaining the scattering state in other regions. ### Claim 3 (depends on 2) The electronic device according to claim 2, wherein the transmission state includes a partial transmission state for making a region overlapping the image sensor partly transparent. ### Claim 4 (depends on 2) The electronic device according to claim 2, wherein when the optical modulation element is in the scattering state, a video image is displayed on the liquid crystal display panel, and when the optical modulation element is in the transmission state, the liquid crystal display panel performs white display in a region overlapping the image sensor, and the image sensor performs imaging. ### Claim 5 (depends on 1) The electronic device according to claim 1, wherein the optical modulation element is a polymer dispersed liquid crystal panel. ### Claim 6 (depends on 1) The electronic device according to claim 1, further comprising a transmissive polarizing plate disposed on a side of the liquid crystal display panel opposite to the first reflective polarizing plate, wherein a transmission polarization axes of the first reflective polarizing plate and the transmissive polarizing plate are disposed in a crossed Nicol's manner, and a transmission polarization axis of the first reflective polarizing plate and the second reflective polarizing plate are disposed in parallel. ### Claim 7 A liquid crystal display device comprising: a liquid crystal display panel having a display region disposed with a plurality of pixels; a lighting unit disposed to overlap the liquid crystal display panel; a first reflective polarizing plate arranged on the lighting unit side of the liquid crystal display panel; and a second reflective polarizing plate disposed between an image sensor and an optical modulation element, wherein the lighting unit includes the optical modulation element disposed to overlap the display region, and a light source for illuminating the optical modulation element, and the optical modulation element is configured to partially form a scattering state and a transmission state in a region overlapping the display region. ### Claim 8 (depends on 7) The liquid crystal display device according to claim 7, wherein the optical modulation element is a polymer dispersed liquid crystal panel. ### Claim 9 (depends on 7) The liquid crystal display device according to claim 7, further comprising a transmissive polarizing plate disposed on a side of the liquid crystal display panel opposite to the second reflective polarizing plate, wherein a transmission polarization axes of the first reflective polarizing plate and the transmissive polarizing plate are disposed in a crossed Nicol's manner, and a transmission polarization axis of the first reflective polarizing plate and that of the second reflective polarizing plate are disposed in parallel.