# US 12,002,425 B2 · Pixel circuit and driving method therefor, 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 12,002,425 B2 - Document ID: US12002425B2 - Status: Granted - Kind: B2 - Application number: 18/038,690 - Filed: 2020-11-30 - Published: 2024-02-01 - Granted: 2024-06-04 - Earliest claimed: 2020-11-30 - Assignees: Boe Technology Group Co., Ltd. - Applicants: BOE Technology Group Co., Ltd. - Inventors: Lujiang Huangfu; Li Wang; Jianchao Zhu; Libin Liu - Web page: https://patentgrep.com/patent/US12002425B2 ## 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 2310/061: for resetting or blanking - G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes - G09G 2330/021: Power management, e.g. power saving - 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 pixel circuit and a driving method therefor, and a display apparatus. The pixel circuit includes a drive transistor, a reset circuit, a data writing circuit, a storage capacitor circuit, a threshold value compensation circuit, a conduction control circuit, a light-emitting control circuit, and a light-emitting device; the conduction control circuit is configured to: conduct the threshold value compensation circuit with the gate of the drive transistor, and conduct the reset circuit with the gate of the drive transistor at the reset stage, the threshold value detecting stage and the data writing stage; and cut off a conducting state of the threshold value compensation circuit with the gate of the drive transistor, and cut off a conducting state of the reset circuit with the gate of the drive transistor at the driving stage; where the conduction control circuit includes an oxide semiconductor thin film transistor. ## Claims ### Claim 1 A pixel circuit, comprising: a drive transistor, a reset circuit, a data writing circuit, a storage capacitor circuit, a threshold value compensation circuit, a conduction control circuit, a light-emitting control circuit, and a light-emitting device; wherein the reset circuit is configured to reset the storage capacitor circuit, a gate of the drive transistor and a first electrode of the light-emitting device at a reset stage; the threshold value compensation circuit is configured to write a threshold voltage of the drive transistor into the storage capacitor circuit at a threshold value detecting stage; the data writing circuit is configured to write a data voltage into the storage capacitor circuit at a data writing stage; the storage capacitor circuit is configured to provide a drive voltage generated by superposition of the data voltage and the threshold value voltage for the gate of the drive transistor at a driving stage; the light-emitting control circuit is configured to conduct a first electrode of the drive transistor and the first electrode of the light-emitting device at the driving stage to drive the light-emitting device to emit light; and the conduction control circuit is configured to: conduct the threshold value compensation circuit with the gate of the drive transistor, and conduct the reset circuit with the gate of the drive transistor at the reset stage, the threshold value detecting stage and the data writing stage; and cut off a conducting state of the threshold value compensation circuit with the gate of the drive transistor, and cut off a conducting state of the reset circuit with the gate of the drive transistor at the driving stage; wherein the conduction control circuit comprises an oxide semiconductor thin film transistor. ### Claim 2 (depends on 1) The pixel circuit according to claim 1, wherein each of the drive transistor, the reset circuit, the data writing circuit, the threshold value compensation circuit and the light-emitting control circuit comprises a low-temperature polycrystalline silicon thin film transistor. ### Claim 3 (depends on 2) The pixel circuit according to claim 2, wherein the storage capacitor circuit comprises: a first capacitor and a second capacitor; one end of the first capacitor is electrically connected with the gate of the drive transistor, and the other end of the first capacitor is electrically connected with one end of the second capacitor, the data writing circuit and the reset circuit; and the other end of the second capacitor is electrically connected with a first reference voltage signal end; wherein the one end of the first capacitor connected with the gate of the drive transistor serves as a first node; the other end of the first capacitor connected with the one end of the second capacitor serves as a second node. ### Claim 4 (depends on 3) The pixel circuit according to claim 3, wherein the conduction control circuit comprises: a first oxide thin film transistor; and a gate of the first oxide thin film transistor is electrically connected with a conduction control signal end, a first electrode of the first oxide thin film transistor is electrically connected with the first node, and a second electrode of the first oxide thin film transistor is electrically connected with the reset circuit and the threshold value compensation circuit respectively. ### Claim 5 (depends on 4) The pixel circuit according to claim 4, wherein the conduction control circuit further comprises: a second oxide thin film transistor; and a gate of the second oxide thin film transistor is electrically connected with the conduction control signal end, a first electrode of the second oxide thin film transistor is electrically connected with the second node, and a second electrode of the second oxide thin film transistor is electrically connected with the data writing circuit and the reset circuit respectively. ### Claim 6 (depends on 5) The pixel circuit according to claim 5 wherein the light-emitting control circuit comprises: a sixth transistor, a gate of the sixth transistor is electrically connected with a light-emitting control signal end, a first electrode of the sixth transistor is electrically connected with the first electrode of the drive transistor, and a second electrode of the sixth transistor is electrically connected with the first electrode of the light-emitting device; and the second electrode of the drive transistor is electrically connected with a first power signal end, and the second electrode of the light-emitting device is electrically connected with a second power signal end. ### Claim 7 (depends on 4) The pixel circuit according to claim 4, wherein the light-emitting control circuit comprises: a sixth transistor, a gate of the sixth transistor is electrically connected with a light-emitting control signal end, a first electrode of the sixth transistor is electrically connected with the first electrode of the drive transistor, and a second electrode of the sixth transistor is electrically connected with the first electrode of the light-emitting device; and the second electrode of the drive transistor is electrically connected with a first power signal end, and the second electrode of the light-emitting device is electrically connected with a second power signal end. ### Claim 8 (depends on 7) The pixel circuit according to claim 7, wherein the sixth transistor is a P-type transistor, and the light-emitting control signal end and the conduction control signal end are a same signal end. ### Claim 9 (depends on 3) The pixel circuit according to claim 3, wherein the data writing circuit comprises: a first transistor, a gate of the first transistor is electrically connected with a first scanning signal end, a first electrode of the first transistor is electrically connected with a data voltage signal end, and a second electrode of the first transistor is electrically connected with the second node. ### Claim 10 (depends on 3) The pixel circuit according to claim 3, wherein the threshold value compensation circuit comprises: a second transistor, a gate of the second transistor is electrically connected with a second scanning signal end, a first electrode of the second transistor is electrically connected with the first electrode of the drive transistor, and a second electrode of the second transistor is electrically connected with the first node through the conduction control circuit. ### Claim 11 (depends on 3) The pixel circuit according to claim 3, wherein the reset circuit comprises: a third transistor, a fourth transistor and a fifth transistor; a gate of the third transistor and a gate of the fourth transistor are electrically connected with a reset signal end respectively, a first electrode of the third transistor and a first electrode of the fourth transistor are electrically connected with an initialized signal end respectively, a second electrode of the third transistor is electrically connected with the first node through the conduction control circuit, and a second electrode of the fourth transistor is electrically connected with the first electrode of the light-emitting device; and a gate of the fifth transistor is electrically connected with a second scanning signal end of a previous pixel row, a first electrode of the fifth transistor is electrically connected with a second reference voltage signal end, and a second electrode of the fifth transistor is electrically connected with the second node. ### Claim 12 (depends on 2) The pixel circuit according to claim 2, wherein the storage capacitor circuit comprises: a third capacitor and a fourth capacitor; one end of the third capacitor is electrically connected with the gate of the drive transistor, one end of the fourth capacitor respectively, and the other end of the third capacitor is electrically connected with a first reference voltage signal end; and the other end of the fourth capacitor is electrically connected with the data writing circuit and the reset circuit respectively; wherein the one end of the third capacitor connected with the gate of the drive transistor serves as a first node; and the other end of the fourth capacitor connected with the data writing circuit and the reset circuit serves as a second node. ### Claim 13 (depends on 12) The pixel circuit according to claim 12, wherein the conduction control circuit comprises: a third oxide thin film transistor; and a gate of the third oxide thin film transistor is electrically connected with a conduction control signal end, a first electrode of the third oxide thin film transistor is electrically connected with the first node, and a second electrode of the third oxide thin film transistor is electrically connected with the one end of the fourth capacitor, the reset circuit and the threshold value compensation circuit respectively. ### Claim 14 (depends on 13) The pixel circuit according to claim 13 wherein the light-emitting control circuit comprises: a sixth transistor, a gate of the sixth transistor is electrically connected with a light-emitting control signal end, a first electrode of the sixth transistor is electrically connected with the first electrode of the drive transistor, and a second electrode of the sixth transistor is electrically connected with the first electrode of the light-emitting device; and the second electrode of the drive transistor is electrically connected with a first power signal end, and the second electrode of the light-emitting device is electrically connected with a second power signal end. ### Claim 15 (depends on 12) The pixel circuit according to claim 12, wherein the data writing circuit comprises: a first transistor, a gate of the first transistor is electrically connected with a first scanning signal end, a first electrode of the first transistor is electrically connected with a data voltage signal end, and a second electrode of the first transistor is electrically connected with the second node. ### Claim 16 (depends on 12) The pixel circuit according to claim 12, wherein the threshold value compensation circuit comprises: a second transistor, a gate of the second transistor is electrically connected with a second scanning signal end, a first electrode of the second transistor is electrically connected with the first electrode of the drive transistor, and a second electrode of the second transistor is electrically connected with the first node through the conduction control circuit. ### Claim 17 (depends on 12) The pixel circuit according to claim 12, wherein the reset circuit comprises: a third transistor, a fourth transistor and a fifth transistor; a gate of the third transistor and a gate of the fourth transistor are electrically connected with a reset signal end respectively, a first electrode of the third transistor and a first electrode of the fourth transistor are electrically connected with an initialized signal end respectively, a second electrode of the third transistor is electrically connected with the first node through the conduction control circuit, and a second electrode of the fourth transistor is electrically connected with the first electrode of the light-emitting device; and a gate of the fifth transistor is electrically connected with a second scanning signal end of a previous pixel row, a first electrode of the fifth transistor is electrically connected with a second reference voltage signal end, and a second electrode of the fifth transistor is electrically connected with the second node. ### Claim 18 (depends on 1) A driving method for the pixel circuit according to claim 1, comprising: at the reset stage: conducting the reset circuit and the gate of the drive transistor by the conduction control circuit; and resetting the storage capacitor circuit, the gate of the drive transistor and the first electrode of the light-emitting device by the reset circuit; at the threshold value detecting stage: conducting the threshold value compensation circuit and the gate of the drive transistor by the conduction control circuit; and writing the threshold voltage of the drive transistor into the storage capacitor circuit by the threshold value compensation circuit; at the data writing stage: writing the data voltage into the storage capacitor circuit by the data writing circuit; and at the driving stage: cutting off the conducting state of the threshold value compensation circuit and the reset circuit respectively with the gate of the drive transistor by the conduction control circuit; and conducting the first electrode of the drive transistor and the first electrode of the light-emitting device to drive the light-emitting device to emit light by the light-emitting control circuit; wherein the reset stage, the threshold value detecting stage, the data writing stage and the driving stage sequentially and continuously form a display frame time period. ### Claim 19 (depends on 1) A display apparatus, comprising the pixel circuit according to claim 1. ### Claim 20 (depends on 19) The display apparatus according to claim 19, wherein each of the drive transistor, the reset circuit, the data writing circuit, the threshold value compensation circuit and the light-emitting control circuit comprises a low-temperature polycrystalline silicon thin film transistor.