# US 11,308,889 B2 · Detection method of pixel circuit, driving method of display panel, and display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,889 B2 - Document ID: US11308889B2 - Status: Granted - Kind: B2 - Application number: 16/329,352 - Filed: 2018-08-24 - Published: 2021-10-28 - Granted: 2022-04-19 - Earliest claimed: 2017-10-20 - Assignees: Boe Technology Group Co., Ltd. - Applicants: Boe Technology Group Co., Ltd. - Inventors: Danna Song; Yi Cheng Lin; Pan Xu; Zhongyuan Wu - Web page: https://patentgrep.com/patent/US11308889B2 ## 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 3/00: Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes - G09G 3/006: {Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309)} - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - 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 2310/08: Details of timing specific for flat panels, other than clock recovery - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0295: by monitoring each display pixel - G09G 2320/043: Preventing or counteracting the effects of ageing - G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - 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 detection method of a pixel circuit, a driving method of a display panel, and a display device are disclosed. The pixel circuit includes a driving transistor; and the detection method of the pixel circuit includes: in the first charge cycle, applying a first data voltage to a gate electrode of the driving transistor, acquiring a first sensing voltage at a first electrode of the driving transistor within the first duration after the application of the first data voltage and before the driving transistor is switched off, and determining whether the first sensing voltage is equal to reference sensing voltage. ## Claims ### Claim 1 A detection method of a pixel circuit, wherein the pixel circuit includes a driving transistor; and the method comprises: in a first charge cycle, applying a first data voltage to a gate electrode of the driving transistor, acquiring a first sensing voltage at a first electrode of the driving transistor within a first duration after application of the first data voltage and before the driving transistor is switched off, and determining whether the first sensing voltage is equal to a reference sensing voltage, wherein the reference sensing voltage is acquired in a reference charge cycle; in the reference charge cycle, the reference sensing voltage is acquired at the first electrode of the driving transistor within the first duration after application of a reference data voltage to the gate electrode of the driving transistor and before the driving transistor is switched off; and the first data voltage is equal to the reference data voltage, wherein the reference charge cycle is in a shutdown state, and the first charge cycle is in a followed boot-up process after the reference charge cycle; or the reference charge cycle is in a boot-up state, and the first charge cycle is in a boot-up process after the reference charge cycle. ### Claim 2 (depends on 1) The detection method according to claim 1, wherein in a case where the first sensing voltage is unequal to the reference sensing voltage, in a second charge cycle, a second data voltage is applied to the gate electrode of the driving transistor, and a second sensing voltage is acquired at the first electrode of the driving transistor within the first duration after application of the second data voltage, in which the second data voltage is selected so that a difference between the second sensing voltage and the reference sensing voltage can be less than a difference between the first sensing voltage and the reference sensing voltage. ### Claim 3 (depends on 2) The detection method according to claim 2, wherein in a case where the first sensing voltage is less than the reference sensing voltage, the second data voltage is greater than the first data voltage; and in a case where the first sensing voltage is greater than the reference sensing voltage, the second data voltage is less than the first data voltage. ### Claim 4 (depends on 2) The detection method according to claim 2, wherein in a case where the second sensing voltage is still unequal to the reference sensing voltage, the second charge cycle is repeated until the second sensing voltage is equal to the reference sensing voltage. ### Claim 5 (depends on 2) The detection method according to claim 2, wherein the first charge cycle and/or the second charge cycle is between display circles. ### Claim 6 (depends on 2) The detection method according to claim 2, further comprising: acquiring a reference threshold voltage of the driving transistor; and in a case where the second sensing voltage is equal to the reference sensing voltage, acquiring a present threshold voltage of the driving transistor, based on the reference threshold voltage, the second data voltage and the reference data voltage, wherein the present threshold voltage of the driving transistor is equal to the reference threshold voltage plus a difference between the second data voltage and the reference data voltage. ### Claim 7 (depends on 6) The detection method according to claim 6, wherein acquiring the reference threshold voltage of the driving transistor comprises: in a shutdown charge cycle of the shutdown state, applying a shutdown data voltage to the gate electrode of the driving transistor, and acquiring a shutdown sensing voltage at the first electrode of the driving transistor after the driving transistor is switched off, in which the reference threshold voltage of the driving transistor is equal to the difference between the shutdown data voltage and the shutdown sensing voltage. ### Claim 8 (depends on 7) The detection method according to claim 7, wherein the shutdown charge cycle is the same as the reference charge cycle, and the shutdown data voltage is equal to the reference data voltage. ### Claim 9 (depends on 1) The detection method according to claim 1, further comprising: acquiring a reference threshold voltage of the driving transistor; and in a case where the first sensing voltage is equal to the reference sensing voltage, acquiring a present threshold voltage of the driving transistor, based on the reference threshold voltage, the first data voltage and the reference data voltage, wherein the present threshold voltage of the driving transistor is equal to the reference threshold voltage plus a difference between the first data voltage and the reference data voltage. ### Claim 10 (depends on 9) The detection method according to claim 9, wherein acquiring the reference threshold voltage of the driving transistor comprises: in a shutdown charge cycle of the shutdown state, applying a shutdown data voltage to the gate electrode of the driving transistor, and acquiring a shutdown sensing voltage at the first electrode of the driving transistor after the driving transistor is switched off, in which the reference threshold voltage of the driving transistor is equal to the difference between the shutdown data voltage and the shutdown sensing voltage. ### Claim 11 (depends on 10) The detection method according to claim 10, wherein the shutdown charge cycle is the same as the reference charge cycle, and the shutdown data voltage is equal to the reference data voltage. ### Claim 12 (depends on 1) A driving method of a display panel, wherein the display panel includes a pixel circuit; and the driving method comprises: acquiring a present threshold voltage of the driving transistor of the pixel circuit by executing the detection method of the pixel circuit according to claim 1 on the pixel circuit. ### Claim 13 (depends on 12) The driving method of the display panel according to claim 12, further comprising: creating a compensation factor for the pixel circuit according to the acquired present threshold voltage. ### Claim 14 A display device, comprising a pixel circuit and a control circuit, wherein the pixel circuit includes a driving transistor; and the control circuit is configured to execute a detection method comprising: in a first charge cycle, applying a first data voltage to a gate electrode of the driving transistor, acquiring a first sensing voltage at a first electrode of the driving transistor within a first duration after application of the first data voltage and before the driving transistor is switched off, and determining whether the first sensing voltage is equal to the reference sensing voltage, in which the reference sensing voltage is acquired in a reference charge cycle; in the reference charge cycle, the reference sensing voltage is acquired at the first electrode of the driving transistor within the first duration after the application of a reference data voltage to the gate electrode of the driving transistor and before the driving transistor is switched off; and the first data voltage is equal to the reference data voltage, wherein the reference charge cycle is in a shutdown state, and the first charge cycle is in a followed boot-up process after the reference charge cycle; or the reference charge cycle is in a boot-up state, and the first charge cycle is in a boot-up process after the reference charge cycle. ### Claim 15 (depends on 14) The display device according to claim 14, further comprising a data drive circuit and a detection circuit, wherein the data drive circuit is configured to output the first data voltage and the reference data voltage; the pixel circuit is further configured to receive the first data voltage and the reference data voltage and apply the first data voltage and the reference data voltage to the gate electrode of the driving transistor; the detection circuit is configured to read the first sensing voltage and the reference sensing voltage from the first electrode of the driving transistor; and the control circuit is further configured to control the data drive circuit and the detection circuit. ### Claim 16 (depends on 15) The display device according to claim 15, wherein the pixel circuit further includes a data write transistor and a storage capacitor; the data write transistor is configured to acquire data signals from the data drive circuit and write the data signals into the gate electrode of the driving transistor; and the storage capacitor is configured to store the data signals. ### Claim 17 (depends on 14) The display device according to claim 14, wherein the pixel circuit further includes a light-emitting element and a sensing switching transistor; a second electrode and the first electrode of the driving transistor are respectively connected to a first supply voltage terminal and a first electrode of the light-emitting element; a second electrode of the light-emitting element is connected to a second supply voltage terminal; a first electrode of the sensing switching transistor is electrically connected with the first electrode of the driving transistor; and a second electrode of the sensing switching transistor is electrically connected with the detection circuit. ### Claim 18 (depends on 17) The display device according to claim 17, wherein the pixel circuit further includes a sensing line; and a second electrode of the sensing switching transistor is electrically connected with the detection circuit through the sensing line. ### Claim 19 (depends on 14) The display device according to claim 14, wherein the control circuit includes a processor and a memory; the memory includes executable codes; and the processor runs the executable codes so as to execute the detection method.