# US 8,786,526 B2 · Active matrix substrate, display device, and organic EL display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,526 B2 - Document ID: US8786526B2 - Status: Granted - Kind: B2 - Application number: 13/386,888 - Filed: 2010-04-02 - Published: 2012-05-24 - Granted: 2014-07-22 - Earliest claimed: 2009-07-28 - Assignees: Sharp Kabushiki Kaisha - Applicants: Noboru Noguchi - Inventors: Noboru Noguchi - Web page: https://patentgrep.com/patent/US8786526B2 ## CPC - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2300/0852: being a dynamic memory with more than one capacitor - 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 2320/0214: with crosstalk due to leakage current of pixel switch in active matrix panels - G09G 2320/0219: Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling - G09G 2320/0252: Improving the response speed - G09G 2320/043: Preventing or counteracting the effects of ageing - 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 The present invention provides an analog gradation-driving active matrix substrate suppressing reduction in the response time of the current-driven light-emitting element; a display device; and an organic EL display device. The active matrix substrate of the present invention is an analog gradation-driving active matrix substrate, comprising: pixels each including a current-driven light-emitting element and a drive transistor, the current-driven light-emitting element has a pixel electrode electrically coupled with the drive transistor, the drive transistor supplies a current to the current-driven light-emitting element through the pixel electrode, wherein an adjusting transistor for adjusting a voltage of the pixel electrode is electrically connected to a path for the electric current supplied from the drive transistor to the current-driven light-emitting element. ## Claims ### Claim 1 An analog gradation-driving active matrix substrate, comprising: pixels each including a current-driven light-emitting element and a drive transistor, the current-driven light-emitting element has a pixel electrode electrically coupled with the drive transistor, the drive transistor supplies a current to the current-driven light-emitting element through the pixel electrode, wherein an adjusting transistor for adjusting a voltage of the pixel electrode is electrically connected to a path for the electric current supplied from the drive transistor to the current-driven light-emitting element; and a first signal line to which a source electrode or a drain electrode of the adjusting transistor is electrically connected is different from a second signal line to which a source electrode or a drain electrode of the drive transistor is electrically connected, wherein a first voltage of the first signal line is lower than a second voltage of the second signal line by a threshold voltage of the drive transistor, the first voltage is applied to the source electrode or the drain electrode of the adjusting transistor, and the second voltage is applied to the source electrode or the drain electrode of the drive transistor. ### Claim 2 (depends on 1) The active matrix substrate according to claim 1, wherein a gate electrode of the drive transistor is provided in a wiring layer which is disposed directly below the pixel electrode. ### Claim 3 (depends on 1) The active matrix substrate according to claim 1, wherein the pixel further includes a compensation circuit for compensating variation of a threshold voltage of the drive transistor. ### Claim 4 (depends on 1) A display device, comprising the active matrix substrate according to claim 1, the display device allowing the current-driven light-emitting element to emit light after voltage adjustment of the pixel electrode by the adjusting transistor. ### Claim 5 (depends on 4) The display device according to claim 4, wherein the voltage adjustment and the light emission are sequentially performed. ### Claim 6 (depends on 1) An organic EL display device, comprising the active matrix substrate according to claim 1, the current-driven light-emitting element being an organic EL element, the pixel electrode being an anode or a cathode of the organic EL element.