# US 8,772,699 B2 · Display device having a photosensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,699 B2 - Document ID: US8772699B2 - Status: Granted - Kind: B2 - Application number: 13/254,422 - Filed: 2010-01-07 - Published: 2011-12-29 - Granted: 2014-07-08 - Earliest claimed: 2009-03-02 - Assignees: Sharp Kabushiki Kaisha - Applicants: Christopher Brown; Kohei Tanaka; Hiromi Katoh - Inventors: Christopher Brown; Kohei Tanaka; Hiromi Katoh - Web page: https://patentgrep.com/patent/US8772699B2 ## CPC - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F 3/042: by opto-electronic means - G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)} - G02F 1/13312: {Circuits comprising photodetectors for purposes other than feedback} - G02F 1/13338: {Input devices, e.g. touch panels} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - 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 The present invention relates to a display device including a photosensor in a pixel region. The photosensor of the present invention includes a diode (D1) that receives incident light, reset signal wiring (RST) that supplies a reset signal, readout signal wiring (RWS) that supplies a readout signal, a storage node (INT) whose potential changes in accordance with the amount of light received by the photodetection element in a sensing period, the sensing period being from when the reset signal is supplied until when the readout signal is supplied, an amplification element (C1) that amplifies the potential of the storage node in accordance with the readout signal, and a sensor switching element (M2) for reading out the potential amplified by the amplification element to output wiring (OUT) as sensor circuit output. ## Claims ### Claim 1 A display device comprising a photosensor in a pixel region of an active matrix substrate, the photosensor comprising: a photodetection element that receives incident light; reset signal wiring that supplies a reset signal to the photosensor; readout signal wiring that supplies a readout signal to the photosensor; a storage node whose potential changes in accordance with the amount of light received by the photodetection element in a sensing period, the sensing period being from when the reset signal is supplied until when the readout signal is supplied; an amplification element that amplifies the potential of the storage node in accordance with the readout signal; and a sensor switching element for reading out the potential amplified by the amplification element to output wiring as sensor circuit output, wherein the amplification element is a diode including a gate electrode over a channel. ### Claim 2 (depends on 1) The display device according to claim 1, comprising a plurality of the photodetection elements in the pixel region, wherein the plurality of photodetection elements are connected in parallel, and the amplification element is connected to a terminal photodetection element among the plurality of photodetection elements. ### Claim 3 (depends on 1) The display device according to claim 1, wherein the sensor switching element is a three-terminal switching element, a gate electrode among the three terminals is connected to the storage node, and one of the two remaining terminals among the three terminals is connected to the output wiring. ### Claim 4 (depends on 1) The display device according to claim 1, wherein the amplification element has a threshold voltage at which the amplification element switches on/off, between a low level potential and a high level potential of the readout signal. ### Claim 5 (depends on 1) The display device according to claim 1, further comprising: a common substrate opposing the active matrix substrate; and liquid crystal sandwiched between the active matrix substrate and the common substrate. ### Claim 6 A display device comprising a photosensor in a pixel region of an active matrix substrate, the photosensor comprising: a photodetection element that receives incident light; reset signal wiring that supplies a reset signal to the photosensor; readout signal wiring that supplies a readout signal to the photosensor; a storage node whose potential changes in accordance with the amount of light received by the photodetection element in a sensing period, the sensing period being from when the reset signal is supplied until when the readout signal is supplied; an amplification element that amplifies the potential of the storage node in accordance with the readout signal; a sensor switching element for reading out the potential amplified by the amplification element to output wiring as sensor circuit output; a light shielding film provided on a side of the photodetection element that is opposite to a light receiving face thereof; and an electrode provided opposing the light shielding film so as to form a series capacitor in series with a parasitic capacitance between the light shielding film and the photodetection element, wherein the electrode is electrically connected to the readout wiring. ### Claim 7 (depends on 6) The display device according to claim 6, comprising a plurality of the photodetection elements in the pixel region, wherein the plurality of photodetection elements are connected in parallel, and the amplification element is connected to a terminal photodetection element among the plurality of photodetection elements. ### Claim 8 (depends on 6) The display device according to claim 6, wherein the sensor switching element is a three-terminal switching element, a gate electrode among the three terminals is connected to the storage node, and one of the two remaining terminals among the three terminals is connected to the output wiring. ### Claim 9 (depends on 6) The display device according to claim 6, wherein the amplification element has a threshold voltage at which the amplification element switches on/off, between a low level potential and a high level potential of the readout signal. ### Claim 10 (depends on 6) The display device according to claim 6, further comprising: a common substrate opposing the active matrix substrate; and liquid crystal sandwiched between the active matrix substrate and the common substrate. ### Claim 11 A display device comprising a photosensor in a pixel region of an active matrix substrate, the photosensor comprising: a photodetection element that receives incident light; reset signal wiring that supplies a reset signal to the photosensor; readout signal wiring that supplies a readout signal to the photosensor; a storage node whose potential changes in accordance with the amount of light received by the photodetection element in a sensing period, the sensing period being from when the reset signal is supplied until when the readout signal is supplied; an amplification element that amplifies the potential of the storage node in accordance with the readout signal; a sensor switching element for reading out the potential amplified by the amplification element to output wiring as sensor circuit output; and a switching element for resetting the sensor switching element. ### Claim 12 (depends on 11) The display device according to claim 11, wherein the amplification element has a threshold voltage at which the amplification element switches on/off, between a low level potential and a high level potential of the readout signal. ### Claim 13 (depends on 11) The display device according to claim 11, further comprising: a common substrate opposing the active matrix substrate; and liquid crystal sandwiched between the active matrix substrate and the common substrate.