# US 10,504,440 B2 · Pixel circuit, driving method thereof, display panel and display apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,440 B2 - Document ID: US10504440B2 - Status: Granted - Kind: B2 - Application number: 15/736,690 - Filed: 2017-07-06 - Published: 2018-12-13 - Granted: 2019-12-10 - Earliest claimed: 2016-08-18 - Assignees: Boe Technology Group Co., Ltd.; Chengdu Boe Optoelectronics Technology Co., Ltd. - Applicants: Boe Technology Group Co., Ltd.; Chengdu Boe Optoelectronics Technology Co., Ltd. - Inventors: Yuhsiung Feng - Web page: https://patentgrep.com/patent/US10504440B2 ## CPC - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element - H10D 86/441: {Interconnections, e.g. scanning lines} - H10D 86/60: wherein the TFTs are in active matrices - H10K 59/131: Interconnections, e.g. wiring lines or terminals - G09G 3/3266: Details of drivers for scan electrodes - 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 2300/0842: forming a memory circuit, e.g. a dynamic memory with 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 2310/0216: Interleaved control phases for different scan lines in the same sub-field, e.g. initialization, addressing and sustaining in plasma displays that are not simultaneous for all scan lines - 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 2310/0264: Details of driving circuits - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - 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) - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES ## Abstract A pixel circuit is disclosed, which includes a light-emitting circuit, a driving circuit, a compensation circuit, and an initialization circuit. The initialization circuit is configured to initialize the driving circuit and the light-emitting circuit with a first voltage in response to a first and third scan signals. The compensation circuit is configured to, in response to a second scan signal, write a data voltage into the driving circuit and perform threshold voltage compensation on the driving circuit. The driving circuit is configured to generate a current dependent upon the written data voltage in response to a light emission control signal. The light-emitting circuit is configured to be driven to emit light by the generated current. Also disclosed are a display panel, a display apparatus, and a method of driving the pixel circuit. ## Claims ### Claim 1 A pixel circuit, comprising a light-emitting circuit, a driving circuit, a compensation circuit, and an initialization circuit, wherein: the initialization circuit is connected to a first voltage terminal, a first scan line, and a third scan line and is configured to initialize the driving circuit and the light-emitting circuit with a first voltage supplied from the first voltage terminal in response to a first scan signal on the first scan line and a third scan signal on the third scan line; the compensation circuit is connected to a second scan line, a data line and a second voltage terminal and is configured to, responsive to a second scan signal on the second scan line, write a data voltage on the data line into the driving circuit and perform threshold voltage compensation on the driving circuit; the driving circuit is connected to the second voltage terminal and a light emission control line and is configured to generate a current dependent on the written data voltage in response to a light emission control signal on the light emission control line; and the light-emitting circuit is connected between the driving circuit and the first voltage terminal and is configured to be driven to emit light by the current, wherein the initialization circuit comprises: a first transistor having a gate connected to the first scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a first node connected between the driving circuit and the light-emitting circuit; and a second transistor having a gate connected to the third scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a second node connected to the driving circuit, and wherein the second transistor and the first transistor are configured to be turned on sequentially in response to the third scan signal and the first scan signal respectively, so as to sequentially initialize the driving circuit and the light-emitting circuit. ### Claim 2 (depends on 1) The pixel circuit of claim 1, wherein the driving circuit comprises: a fifth transistor having a source, a drain, and a gate, the gate being connected to the second node; a sixth transistor having a gate connected to the light emission control line, a first electrode connected to the second voltage terminal, and a second electrode connected to the source of the fifth transistor; and a seventh transistor having a gate connected to the light emission control line, a first electrode connected to the drain of the fifth transistor, and a second electrode connected to the first node. ### Claim 3 (depends on 2) The pixel circuit of claim 2, wherein the compensation circuit comprises: a third transistor having a gate connected to the second scan line, a first electrode connected to the drain of the fifth transistor, and a second electrode connected to the second node; a fourth transistor having a gate connected to the second scan line, a first electrode connected to the data line, and a second electrode connected to the source of the fifth transistor; and a capacitor having a first terminal connected to the second voltage terminal and a second terminal connected to the second node. ### Claim 4 (depends on 2) The pixel circuit of claim 2, wherein the light-emitting circuit comprises an organic light-emitting diode having a first terminal connected to the first node and a second terminal connected to the first voltage terminal. ### Claim 5 (depends on 4) The pixel circuit of claim 4, wherein the fifth transistor is a P-type transistor, wherein the first terminal of the organic light-emitting diode is an anode, and wherein the second terminal of the organic light-emitting diode is a cathode. ### Claim 6 (depends on 4) The pixel circuit of claim 4, wherein the fifth transistor is an N-type transistor, wherein the first terminal of the organic light-emitting diode is a cathode, and wherein the second terminal of the organic light-emitting diode is an anode. ### Claim 7 A display panel comprising: a plurality of scan lines arranged in a first direction; a plurality of light emission control lines arranged in the first direction; a plurality of data lines arranged in a second direction intersecting the first direction; and a pixel array comprising a plurality of pixel circuits arranged at intersections of the scanning lines, the light emission control lines and the data lines, each of the pixel circuits being connected to three respective ones of the scanning lines and a respective one of the light emission control lines and comprising a light-emitting circuit, a driving circuit, a compensation circuit, and an initialization circuit, wherein: the initialization circuit is connected to a first voltage terminal and first and third ones of the three respective scan lines and is configured to initialize the driving circuit and the light-emitting circuit with a first voltage supplied from the first voltage terminal in response to a first scan signal on the first scan line and a third scan signal on the third scan line; the compensation circuit is connected to a second one of the three respective scan lines, a data line and a second voltage terminal and is configured to, responsive to a second scan signal on the second scan line, write a data voltage on the data line into the driving circuit and perform threshold voltage compensation on the driving circuit; the driving circuit is connected to the second voltage terminal and the respective light emission control line and is configured to generate, responsive to a light-emitting control signal on the respective light emission control line, a current dependent on the written data voltage; and the light-emitting circuit is connected between the driving circuit and the first voltage terminal and is configured to be driven to emit light by the current, wherein the initialization circuit comprises: a first transistor having a gate connected to the first scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a first node connected between the driving circuit and the light-emitting circuit; and a second transistor having a gate connected to the third scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a second node connected to the driving circuit, and wherein the second transistor and the first transistor are configured to be turned on sequentially in response to the third scan signal and the first scan signal respectively, so as to sequentially initialize the driving circuit and the light-emitting circuit. ### Claim 8 (depends on 7) The display panel of claim 7, wherein the driving circuit comprises: a fifth transistor having a source, a drain, and a gate connected to the second node; a sixth transistor having a gate connected to the respective light emission control line, a first electrode connected to the second voltage terminal, and a second electrode connected to the source of the fifth transistor; and a seventh transistor having a gate connected to the respective light emission control line, a first electrode connected to the drain of the fifth transistor, and a second electrode connected to the first node. ### Claim 9 (depends on 8) The display panel of claim 8, wherein the compensation circuit comprises: a third transistor having a gate connected to the second scan line, a first electrode connected to the drain of the fifth transistor, and a second electrode connected to the second node; a fourth transistor having a gate connected to the second scan line, a first electrode connected to the data line, and a second electrode connected to the source of the fifth transistor; and a capacitor having a first terminal connected to the second voltage terminal and a second terminal connected to the second node. ### Claim 10 (depends on 8) The display panel of claim 8, wherein the light-emitting circuit comprises an organic light-emitting diode having a first terminal connected to the first node and a second terminal connected to the first voltage terminal. ### Claim 11 (depends on 10) The display panel of claim 10, wherein the fifth transistor is a P-type transistor, wherein the first terminal of the organic light-emitting diode is an anode, and wherein the second terminal of the organic light-emitting diode is a cathode. ### Claim 12 (depends on 10) The display panel of claim 10, wherein the fifth transistor is an N-type transistor, wherein the first terminal of the organic light-emitting diode is a cathode, and wherein the second terminal of the organic light-emitting diode is an anode. ### Claim 13 (depends on 7) A display apparatus comprising the display panel as claimed in claim 7. ### Claim 14 A method of driving a pixel circuit, the pixel circuit comprising an initialization circuit connected to a first voltage terminal, a first scan line, and a third scan line, a compensation circuit connected to a second scan line, a data line, and a second voltage terminal, a driving circuit connected to the second voltage terminal and a light emission control line, and a light-emitting circuit connected between the driving circuit and the first voltage terminal, wherein the initialization circuit comprises: a first transistor having a gate connected to the first scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a first node connected between the driving circuit and the light-emitting circuit; and a second transistor having a gate connected to the third scan line, a first electrode connected to the first voltage terminal, and a second electrode connected to a second node connected to the driving circuit, and the method comprising: initializing, by the initialization circuit, the driving circuit and the light-emitting circuit with a first voltage supplied from the first voltage terminal in response to a first scan signal on the first scan line and a third scan signal on the third scan line; writing, by the compensation circuit in response to a second scan signal on the second scan line, a data voltage on the data line into the driving circuit and performing threshold voltage compensation on the driving circuit; and supplying, by the driving circuit in response to a light-emitting control signal on the light emission control line, a current dependent on the written data voltage to drive the light-emitting circuit to emit light, wherein the initializing the driving circuit and the light-emitting circuit comprises sequentially turning on the second transistor and the first transistor in response to the third scan signal and the first scan signal respectively, so as to sequentially initialize the driving circuit and the light-emitting circuit. ### Claim 15 (depends on 14) The method of claim 14, wherein the compensation circuit comprises a third transistor, a fourth transistor, and a capacitor, wherein the driving circuit comprises a fifth transistor, a sixth transistor, and a seventh transistor, wherein the light-emitting circuit comprises an organic light-emitting diode, and wherein: the initializing the driving circuit and the light-emitting circuit further comprises applying the first voltage to a gate of the fifth transistor and both ends of the light-emitting diode through the first and second transistors, respectively; the writing the data voltage into the driving circuit and performing the threshold voltage compensation on the driving circuit comprises writing the data voltage and a threshold voltage of the fifth transistor into a gate of the fifth transistor through the fourth, fifth, and third transistors; and the supplying the current to the light-emitting circuit comprises providing a current path through which the current flows, the current path comprising the sixth, fifth and seventh transistors and the organic light-emitting diode connected in series. ### Claim 16 (depends on 15) The method of claim 15, wherein the applying the first voltage to the gate of the fifth transistor and the both ends of the organic light-emitting diode through the first and second transistors respectively comprises turning on the first and second transistors during two consecutive periods of time respectively.