# US 2019/0318684 A1 · Pixel compensation circuit, method for compensating pixel driving circuit, 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 2019/0318684 A1 - Document ID: US20190318684A1 - Status: Published application - Kind: A1 - Application number: 16/346,519 - Filed: 2018-11-12 - Published: 2019-10-17 - Earliest claimed: 2018-04-11 - Assignees: Boe Technology Group Co., Ltd. - Inventors: Cuili GAI; Yicheng LIN; Ling WANG; Pan XU - Web page: https://patentgrep.com/patent/US20190318684A1 ## CPC - G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED] - G09G 3/3225: using an active matrix - G09G 3/3233: with pixel circuitry controlling the current through 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 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/029: by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel - G09G 2320/0295: by monitoring each display pixel - G09G 2360/145: the light originating from the display screen - G09G 2360/147: the originated light output being determined for each pixel - 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 method for compensating the pixel driving circuit may include: in a light emitting phase of the pixel driving circuit, sensing an electric signal of the first electrode of the electroluminescent element, and calculating an electrical compensation signal based on the electric signal; in the light emitting phase of the pixel driving circuit, sensing a brightness signal of the electroluminescent element by a photosensitive sensor and calculating an optical compensation signal according to the brightness signal; and generating a comprehensive compensation signal according to the electrical compensation signal and the optical compensation signal, and controlling a signal on a control terminal of the drive transistor according to the comprehensive compensation signal. ## Claims ### Claim 1 A method for compensating a pixel driving circuit, the pixel driving circuit comprising a drive transistor connected to a first electrode of an electroluminescent element, and the method for compensating a pixel driving circuit comprising: in a light emitting phase of the pixel driving circuit, sensing an electric signal of the first electrode of the electroluminescent element, and calculating an electrical compensation signal based on the electric signal; in the light emitting phase of the pixel driving circuit, sensing a brightness signal of the electroluminescent element by a photosensitive sensor, and calculating an optical compensation signal according to the brightness signal; and generating a comprehensive compensation signal according to the electrical compensation signal and the optical compensation signal, and controlling a signal on a control terminal of the drive transistor according to the comprehensive compensation signal. ### Claim 2 (depends on 1) The method for compensating the pixel driving circuit according to claim 1, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the electroluminescent element to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 3 (depends on 1) The method for compensating the pixel driving circuit according to claim 1, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the drive transistor to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 4 A pixel compensation circuit configured to provide a comprehensive compensation signal to a pixel driving circuit, the pixel driving circuit comprising a drive transistor connected to a first electrode of an electroluminescent element, and the pixel compensation circuit comprising: an external electrical compensation sub-circuit, configured to sense, in a light emitting phase of the pixel driving circuit, an electric signal of the first electrode of the electroluminescent element; an external optical compensation sub-circuit, configured to sense, in the light emitting phase of the pixel driving circuit, a brightness signal of the electroluminescent element by a photosensitive sensor; and a processor configured to: calculate an electrical compensation signal according to the electric signal; calculate an optical compensation signal according to the brightness signal; generate a compensative compensation signal according to the electrical compensation signal and the optical compensation signal; and control a signal on a control terminal of the drive transistor according to the comprehensive compensation signal. ### Claim 5 (depends on 4) The pixel compensation circuit according to claim 4, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the electroluminescent element to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 6 (depends on 4) The pixel compensation circuit according to claim 4, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the drive transistor to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 7 (depends on 4) The pixel compensation circuit according to claim 4, wherein the external electrical compensation sub-circuit comprises a first switch element and a sense line, wherein: the first switch element is connected to the first electrode of the electroluminescent element and is configured to be enabled in response to a scanning signal to communicate the first electrode of the electroluminescent element with the sense line; and the sense line is connected to the first switch element and is configured to sense, by the first switch element, an electric signal of the first electrode of the electroluminescent element, and transmit the electric signal to the processor. ### Claim 8 (depends on 7) The pixel compensation circuit according to claim 7, wherein: the first switch element comprises a first terminal, a second terminal, and a control terminal; and the control terminal receives the scanning signal, the first terminal is connected to the first electrode of the electroluminescent element, and the second terminal is connected to the sense line. ### Claim 9 (depends on 4) The pixel compensation circuit according to claim 4, wherein the external optical compensation sub-circuit comprises the photosensitive sensor and a second switch element, wherein: the photosensitive sensor is configured to sense, in the light emitting phase of the pixel driving circuit, a brightness signal of the electroluminescent element; and the second switch element is connected between the sense line and the photosensitive sensor, and is configured to be enabled in response to a scanning signal, such that the brightness signal sensed by the photosensitive sensor is transmitted to the processor through the sense line. ### Claim 10 (depends on 9) The pixel compensation circuit according to claim 9, wherein the second switch element comprises a control terminal, a first terminal, and a second terminal, wherein: the control terminal receives the scanning signal, the first terminal is connected to the sense line, and the second terminal is connected to the photosensitive sensor. ### Claim 11 (depends on 4) A display device, comprising the pixel compensation circuit according to claim 4. ### Claim 12 (depends on 11) The display device according to claim 11, further comprising a substrate, wherein the pixel compensation circuit comprises an external electrical compensation sub-circuit and an external optical compensation sub-circuit; the external electrical compensation sub-circuit is arranged on the substrate of the display device; the external optical compensation sub-circuit is arranged at a light exit side of the electroluminescent element; and a photosensitive sensor in the external optical compensation sub-circuit directly faces the electroluminescent element in the display device. ### Claim 13 (depends on 12) The display device according to claim 12, wherein the processor is integrated into a drive integrated circuit of the display device. ### Claim 14 (depends on 11) The display device according to claim 11, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the electroluminescent element to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 15 (depends on 11) The display device according to claim 11, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the drive transistor to acquire the electric signal of the first electrode of the electroluminescent element. ### Claim 16 (depends on 11) The display device according to claim 11, wherein: the external electrical compensation sub-circuit comprises a first switch element and a sense line; the first switch element is connected to the first electrode of the electroluminescent element and is configured to be enabled in response to a scanning signal to communicate the first electrode of the electroluminescent element with the sense line; and the sense line is connected to the first switch element and is configured to sense, by the first switch element, an electric signal of the first electrode of the electroluminescent element, and transmit the electric signal to the processor. ### Claim 17 (depends on 16) The display device according to claim 16, wherein: the first switch element comprises a first terminal, a second terminal, and a control terminal; and the control terminal receives the scanning signal, the first terminal is connected to the first electrode of the electroluminescent element, and the second terminal is connected to the sense line. ### Claim 18 (depends on 11) The display device according to claim 11, wherein: the external optical compensation sub-circuit comprises the photosensitive sensor and a second switch element; the photosensitive sensor is configured to sense, in the light emitting phase of the pixel driving circuit, a brightness signal of the electroluminescent element; and the second switch element is connected between the sense line and the photosensitive sensor, and is configured to be enabled in response to a scanning signal, such that the brightness signal sensed by the photosensitive sensor is transmitted to the processor through the sense line. ### Claim 19 (depends on 18) The display device according to claim 18, wherein the second switch element comprises a control terminal, a first terminal, and a second terminal, wherein the control terminal receives the scanning signal, the first terminal is connected to the sense line, and the second terminal is connected to the photosensitive sensor. ### Claim 20 (depends on 12) The display device according to claim 12, wherein the sensing an electric signal of the first electrode of the electroluminescent element comprises: sensing a current signal flowing through the electroluminescent element to acquire the electric signal of the first electrode of the electroluminescent element.