# US 11,308,880 B2 · Light emitting display device and driving method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,880 B2 - Document ID: US11308880B2 - Status: Granted - Kind: B2 - Application number: 17/127,337 - Filed: 2020-12-18 - Published: 2021-07-01 - Granted: 2022-04-19 - Earliest claimed: 2019-12-27 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Jung-Jae Kim; Yong-Chul Kwon; Soon-Dong Cho; Sang-Uk Lee; Dongwon Park - Web page: https://patentgrep.com/patent/US11308880B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - G09G 3/3266: Details of drivers for scan electrodes - G09G 3/3275: Details of drivers for data electrodes - G09G 2300/0861: with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes - G09G 2310/0251: Precharge or discharge of pixel before applying new pixel voltage - G09G 2310/0262: The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes - G09G 2310/0286: Details of a shift registers arranged for use in a driving circuit - G09G 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/0223: Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - G09G 2330/028: Generation of voltages supplied to electrode drivers in a matrix display other than LCD - 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 A light emitting display device includes a display panel, a power supply configured to supply a first potential voltage and a second potential voltage to the display panel, and a switch circuit unit configured to sense the first potential voltage applied to the display panel and to feedback the first potential voltage to the power supply, wherein the power supply compensates for the first potential voltage based on the first potential voltage fed back from the switch circuit unit and to output the compensated first potential voltage. ## Claims ### Claim 1 A light emitting display device, comprising: a display panel; a scan driver including a shift register configured to supply a scan signal to the display panel; a power supply configured to supply a first potential voltage and a second potential voltage to the display panel; and a switch circuit configured to: sense the first potential voltage applied to the display panel; and feedback the first potential voltage to the power supply, wherein the power supply is further configured to: compensate for the first potential voltage based on the first potential voltage fed back from the switch circuit; and output a compensated first potential voltage, wherein the switch circuit is electrically connected to the shift register circuit, wherein the switch circuit comprises a plurality of switches positioned in a non-display area of the display panel, and wherein the plurality of switches are configured to be sequentially turned on in response to scan signals that are sequentially output from the shift register circuit. ### Claim 2 (depends on 1) The light emitting display device of claim 1, wherein the switch circuit is further configured to: sense the first potential voltage applied at least one scan line on the display panel; and feed back the first potential voltage to the power supply. ### Claim 3 (depends on 1) The light emitting display device of claim 1, wherein the power supply is further configured to compensate for the first potential voltage in real time based on the first potential voltage feedback from the switch circuit and a reference voltage. ### Claim 4 (depends on 1) The light emitting display device of claim 1, wherein the first potential voltage is compensated for at a higher level away from a input point for the first potential voltage, disposed on the display panel. ### Claim 5 (depends on 1) The light emitting display device of claim 1, wherein the display panel comprises a light emitting diode comprising a light-emitting layer in which at least two layers are stacked. ### Claim 6 (depends on 5) The light emitting display device of claim 5, wherein the light-emitting layer in which the at least two layers are stacked is configured to: emit light with a same color to represent a single color; or emit light with different colors to represent white. ### Claim 7 (depends on 3) The light emitting display device of claim 3, wherein the reference voltage is set to a representative value for representing a voltage for each scan line of the display panel. ### Claim 8 A method of driving a light emitting display device, including a display panel, a scan driver including a shift register configured to supply a scan signal to the display panel, a power supply configured to supply a first potential voltage and a second potential voltage to the display panel, and a switch circuit configured to sense the first potential voltage applied to the display panel, the switch circuit being electrically connected to the shift register circuit, the switch circuit comprising a plurality of switches positioned in a non-display area of the display panel, the method comprising: sensing the first potential voltage applied to the display panel; feeding back the first potential voltage to the power supply; and compensating for the first potential voltage to be applied to the display panel based on the fed back first potential voltage, wherein the plurality of switches are sequentially turned on in response to scan signals that are sequentially output from the shift register circuit. ### Claim 9 (depends on 8) The method of claim 8, wherein the compensating for the first potential voltage to be applied to the display panel comprises compensating for the first potential voltage in real time based on the fed back first potential voltage and a reference voltage. ### Claim 10 (depends on 8) The method of claim 8, wherein the first potential voltage is compensated for at a higher level away from a input point for the first potential voltage, disposed on the display panel. ### Claim 11 (depends on 8) The method of claim 8, wherein the sensing the first potential voltage comprises sensing the first potential voltage applied at least one scan line on the display panel. ### Claim 12 (depends on 9) The method of claim 9, wherein the reference voltage is set to a representative value for representing a voltage for each scan line of the display panel. ### Claim 13 (depends on 1) The light emitting display device of claim 1, wherein: the shift register circuit and the switch circuit are integrated into one device; and the shift register circuit and the switch circuit are disposed in the non-display area of the display panel.