# US 2020/0401258 A1 · Touchscreen Display Device, Touch Driving Circuit, and Driving Method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401258 A1 - Document ID: US20200401258A1 - Status: Published application - Kind: A1 - Application number: 16/883,426 - Filed: 2020-05-26 - Published: 2020-12-24 - Earliest claimed: 2019-06-20 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Seongkyu KANG; SungChul KIM; HoonBae KIM; SunYeop KIM - Web page: https://patentgrep.com/patent/US20200401258A1 ## CPC - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F 3/04164: {Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads} - G06F 3/04166: {Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184)} - G06F 3/0418: {for error correction or compensation, e.g. based on parallax, calibration or alignment} - G06F 3/044: by capacitive means - G06F 3/0443: {using a single layer of sensing electrodes} - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} - G09G 3/2007: {Display of intermediate tones} - G09G 3/3275: Details of drivers for data electrodes - G09G 3/3685: {Details of drivers for data electrodes} - G09G 3/3688: {suitable for active matrices only} - G09G 2320/0276: for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction - 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) ## Abstract Provided are a touchscreen display device, a touch driving circuit, and a driving method. Image display and touch sensing are simultaneously performed and the interference between display driving and touch driving are minimized or removed, so that excellent image display and touch sensing performance is obtained. Poor touch sensitivity occurring in a specific area (e.g. an edge area) is reduced by using differential sensing sequence control, internal correction resistors of the touch driving circuit, and signal characteristics control. ## Claims ### Claim 1 A touchscreen display device comprising: a display panel including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch lines; and a touch driving circuit located on one side of the display panel, electrically connected to the plurality of touch electrodes through the plurality of touch lines, and configured to differentially sense at least two touch electrodes selected from among the plurality of touch electrodes, wherein the plurality of touch electrodes include n number of touch electrodes disposed in order, a first touch electrode among the n number of touch electrodes being disposed farthest from the touch driving circuit, and an nth touch electrode among the n number of touch electrodes being disposed closest to the touch driving circuit, wherein n is an integer greater than or equal to 3, and during a first sensing timing period, the touch driving circuit is configured to differentially sense a third touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and a second touch electrode selected as a reference touch electrode from among the n number of touch electrodes, and is configured to differentially sense the first touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and the nth touch electrode selected as a reference touch electrode from among the n number of touch electrodes. ### Claim 2 (depends on 1) The touchscreen display device according to claim 1, wherein, during a second sensing timing period different from the first sensing timing period, the touch driving circuit is configured to differentially sense the nth touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and an (n−1)th touch electrode selected as a reference touch electrode from among the n number of touch electrodes. ### Claim 3 (depends on 1) The touchscreen display device according to claim 1, wherein, during a second sensing timing period different from the first sensing timing period, the touch driving circuit is configured to differentially sense the second touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and the first touch electrode selected as a reference touch electrode from among the n number of touch electrodes. ### Claim 4 (depends on 1) The touchscreen display device according to claim 1, wherein, in a touch electrode pair in which the first touch electrode is the sensing touch electrode and the nth touch electrode is the reference touch electrode, the reference touch electrode has a smaller time constant than that of the sensing touch electrode, and in another touch electrode pair other than the touch electrode pair in which the first touch electrode is the sensing touch electrode and the nth touch electrode is the reference touch electrode, the reference touch electrode has a greater time constant than that of the sensing touch electrode. ### Claim 5 (depends on 1) The touchscreen display device according to claim 1, wherein the touch driving circuit includes: a differential amplifier configured to differentially sense two touch electrodes selected from among the plurality of touch electrodes; and a first correction resistor and a second correction resistor configured to be respectively electrically connected between the two touch electrodes and the differential amplifier, wherein, during the first sensing timing period, the differential amplifier is configured to differentially sense the first touch electrode selected as the sensing touch electrode and the nth touch electrode selected as the reference touch electrode, the first correction resistor is configured to be electrically connected between the nth touch electrode selected as the reference touch electrode and the differential amplifier, the second correction resistor is configured to be electrically connected between the first touch electrode selected as the sensing touch electrode and the differential amplifier, and the first correction resistor and the second correction resistor are variable resistors. ### Claim 6 (depends on 5) The touchscreen display device according to claim 5, wherein, during the first sensing timing period, the first correction resistor is configured to have a higher resistance than the second correction resistor. ### Claim 7 (depends on 6) The touchscreen display device according to claim 6, wherein, during a second sensing timing period different from the first sensing timing period, the differential amplifier is configured to differentially sense the nth touch electrode selected as the sensing touch electrode and an (n−1)th touch electrode selected as the reference touch electrode, the first correction resistor is configured to be electrically connected between the (n−1)th touch electrode selected as the reference touch electrode and the differential amplifier, and the second correction resistor is configured to be electrically connected between the nth touch electrode selected as the sensing touch electrode and the differential amplifier. ### Claim 8 (depends on 7) The touchscreen display device according to claim 7, wherein, during the second sensing timing period, the second correction resistor is configured to have a higher resistance than the first correction resistor. ### Claim 9 A touchscreen display device comprising: a display panel including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch lines; a gate driving circuit configured to sequentially output gate signals to the plurality of gate lines; a data driving circuit configured to output data signals, converted from digital image signals in response to a gamma reference voltage, to the plurality of data lines; a touch driving circuit configured to output a touch electrode driving signal to at least one touch electrode among the plurality of touch electrodes; a first power circuit configured to supply the touch electrode driving signal to the touch driving circuit; a second power circuit configured to supply the gamma reference voltage, signal characteristics of which correspond to those of the touch electrode driving signal, to the data driving circuit; and a delay resistor configured to be disposed on a path through which the touch electrode driving signal is transferred from the first power circuit to the display panel through the touch driving circuit. ### Claim 10 (depends on 9) The touchscreen display device according to claim 9, wherein a voltage variation gradient of the touch electrode driving signal between the delay resistor and the display panel is smaller than a voltage variation gradient of the touch electrode driving signal between the first power circuit and the delay resistor. ### Claim 11 (depends on 9) The touchscreen display device according to claim 9, wherein the delay resistor is disposed on a printed circuit between the first power circuit and the touch driving circuit or is connected to an output port of the first power circuit. ### Claim 12 (depends on 9) The touchscreen display device according to claim 9, wherein the first power circuit is included in a touch power integrated circuit, and the second power circuit is provided outside the touch power integrated circuit. ### Claim 13 A touchscreen display device comprising: a display panel including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch lines; a gate driving circuit configured to sequentially output gate signals to the plurality of gate lines; a data driving circuit configured to output data signals, converted from digital image signals in response to a plurality of gamma reference voltages, to the plurality of data lines; a touch driving circuit configured to output a touch electrode driving signal to at least one touch electrode among the plurality of touch electrodes; a first power circuit configured to supply the touch electrode driving signal to the touch driving circuit; a second power circuit configured to supply the plurality of gamma reference voltages, signal characteristics of which correspond to those of the touch electrode driving signal, to the data driving circuit; and rapid resistors configured to be disposed on a circuit generating one or more gamma reference voltages among the plurality of gamma reference voltages or disposed on a path through which one or more gamma reference voltages among the plurality of gamma reference voltages are transferred. ### Claim 14 (depends on 13) The touchscreen display device according to claim 13, wherein the second power circuit includes a plurality of voltage distribution circuits configured to output the plurality of gamma reference voltages as distribution voltages, each of the plurality of voltage distribution circuits includes distribution resistors connected between a modulation driving voltage and a modulated base voltage, the distribution resistors in a voltage distribution circuit configured to output a lowest gamma reference voltage, among the plurality of voltage distribution circuits, have a lower resistance than the distribution resistors in remaining voltage distribution circuits among the plurality of voltage distribution circuits, and the distribution resistors in a voltage distribution circuit configured to output a lowest gamma reference voltage, among the plurality of voltage distribution circuits, are the rapid resistors. ### Claim 15 (depends on 13) The touchscreen display device according to claim 13, wherein a voltage variation gradient of the data signals corresponds to a voltage variation gradient of the touch electrode driving signal. ### Claim 16 (depends on 14) The touchscreen display device according to claim 14, wherein each of the modulated driving voltage and the modulated base voltage has signal characteristics corresponding to those of the touch electrode driving signal. ### Claim 17 (depends on 16) The touchscreen display device according to claim 16, wherein the second power circuit includes a driving multiplexer configured to generate the modulated driving voltage, signal characteristics of which correspond to those of the touch electrode driving signal, and a base multiplexer configured to generate the modulated base voltage, signal characteristics of which correspond to those of the touch electrode driving signal. ### Claim 18 (depends on 13) The touchscreen display device according to claim 13, wherein the first power circuit is configured to be included in a touch power integrated circuit, and the second power circuit is configured to be provided outside the touch power integrated circuit. ### Claim 19 A method of driving a touchscreen display device including a display panel including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch lines, the method comprising: differentially sensing, by a touch driving circuit in the touchscreen display device, two touch electrodes selected from among the plurality of touch electrodes; and detecting a touch according to a result of the differential sensing, wherein the plurality of touch electrodes include n number of touch electrodes disposed in order, a first touch electrode among the n number of touch electrodes being disposed farthest from the touch driving circuit, and an nth touch electrode among the n number of touch electrodes being disposed closest to the touch driving circuit, wherein n is an integer greater than or equal to 3, and wherein, in the differential sensing, the touch driving circuit differentially senses a third touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and a second touch electrode selected as a reference touch electrode from among the n number of touch electrodes, and differentially senses the first touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and the nth touch electrode selected as a reference touch electrode from among the n number of touch electrodes. ### Claim 20 A touch driving circuit of a touchscreen display device including a display panel including a plurality of data lines, a plurality of gate lines, a plurality of touch electrodes, and a plurality of touch lines, the touch driving circuit comprises: a differential amplifier configured to differentially sense two touch electrodes selected from among the plurality of touch electrodes; and an analog-to-digital converter configured to output a sensing value in accordance with an output signal of the differential amplifier, wherein the touch driving circuit is located on one side of the display panel, the plurality of touch electrodes include n number of touch electrodes disposed in order, wherein n is an integer greater than or equal to 3, a first touch electrode among the n number of touch electrodes is disposed farthest from the touch driving circuit, and an nth touch electrode among the n number of touch electrodes being disposed closest to the touch driving circuit, and the differential amplifier is configured to differentially sense a third touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and a second touch electrode selected as a reference touch electrode from among the n number of touch electrodes, and is configured to differentially sense the first touch electrode selected as a sensing touch electrode from among the n number of touch electrodes and the nth touch electrode selected as a reference touch electrode from among the n number of touch electrodes.