# US 10,769,976 B2 · Display device, pixel correction circuit and pixel correction method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,769,976 B2 - Document ID: US10769976B2 - Status: Granted - Kind: B2 - Application number: 16/033,373 - Filed: 2018-07-12 - Published: 2019-07-04 - Granted: 2020-09-08 - Earliest claimed: 2018-01-02 - Assignees: Boe Technology Group Co., Ltd. - Applicants: Boe Technology Group Co., Ltd. - Inventors: Chihjen Cheng; Wei Liu; Pengpeng Wang - Web page: https://patentgrep.com/patent/US10769976B2 ## CPC - G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} - G09G 2300/0814: used for selection purposes, e.g. logical AND for partial update - G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing - G09G 2300/0833: forming a linear amplifier or follower - 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 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements - G09G 2320/0626: for control of overall brightness - 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 pixel correction circuit includes a signal input circuit, a follower and a reading circuit. The signal input circuit is used to apply a first signal and a second signal to the follower in a correction mode. An input terminal of the follower is coupled to the signal input circuit. The follower is used to receive the first signal and the second signal sequentially, output a first follow-up signal dependent on the first signal, and output a second follow-up signal dependent on the second signal. The reading circuit is coupled to an output terminal of the follower, and reads the first follow-up signal and then generates a first read signal, and reads the second follow-up signal and then generates a second read signal. The reading circuit uses the first signal, the second signal, the first read signal and the second read signal to calculate a compensation gain. ## Claims ### Claim 1 A pixel correction circuit comprising: a signal input circuit; a follower; and a reading circuit; wherein the signal input circuit is configured to apply a first signal and a second signal to the follower in a correction mode; wherein an input terminal of the follower is coupled to the signal input circuit; the follower is configured to receive the first signal and the second signal sequentially, output a first follow-up signal dependent on the first signal when receiving the first signal, and output a second follow-up signal dependent on the second signal when receiving the second signal; wherein the reading circuit is coupled to an output terminal of the follower, the reading circuit reads the first follow-up signal and then generates a first read signal, and reads the second follow-up signal and then generates a second read signal; and wherein the reading circuit uses the first signal, the second signal, the first read signal and the second read signal to calculate a compensation gain, thereby enabling the reading circuit to perform compensation correction based on the compensation gain, wherein the reading circuit is further configured to, obtain a first voltage difference of the first signal and the second signal; obtain a second voltage difference of the first read signal and the second read signal; and take a ratio of the first voltage difference to the second voltage difference as the compensation gain. ### Claim 2 (depends on 1) The pixel correction circuit of claim 1, wherein the signal input circuit includes: a signal supply terminal configured to supply the first signal and the second signal in the correction mode; a control signal receiving terminal configured to receive a first control signal and a second control signal in the correction mode; and a reset transistor; wherein a first terminal of the reset transistor is coupled to the signal supply terminal; a second terminal of the reset transistor is coupled to the input terminal of the follower; a control terminal of the reset transistor is coupled to the control signal receiving terminal; and wherein when the reset transistor is turned on under control of the first control signal, the follower receives the first signal; and when the reset transistor is turned on under control of the second control signal, the follower receives the second signal. ### Claim 3 (depends on 2) The pixel correction circuit of claim 2, wherein the follower includes a follower transistor; a control terminal of the follower transistor is taken as the input terminal of the follower and is coupled to the second terminal of the reset transistor a first terminal of the follower transistor is coupled to a first power supply; and a second terminal of the follower transistor is taken as the output terminal of the follower and is coupled to the reading circuit. ### Claim 4 (depends on 1) The pixel correction circuit of claim 1, wherein the follower includes a follower transistor, a control terminal of the follower transistor is taken as the input terminal of the follower and is coupled to the signal input circuit; a first terminal of the follower transistor is coupled to a first power supply; and a second terminal of the follower transistor is taken as the output terminal of the follower and is coupled to the reading circuit. ### Claim 5 (depends on 4) The pixel correction circuit of claim 4, wherein the reading circuit includes an amplifier and the amplifier is coupled to the second terminal of the follower transistor. ### Claim 6 (depends on 4) The pixel correction circuit of claim 4, wherein the second terminal of the follower transistor is a source terminal. ### Claim 7 (depends on 4) The pixel correction circuit of claim 4, wherein the follower further includes a first transistor a first terminal of the first transistor is coupled to the second terminal of the follower transistor a second terminal of the first transistor is coupled to a second power supply; and a control terminal of the first transistor is coupled to a first transistor control terminal. ### Claim 8 (depends on 1) The pixel correction circuit of claim 1, wherein the reading circuit reads row by row first follow-up signals and second follow-up signals output by followers in each row of pixels, generate corresponding first read signals and second read signals, and then use the first signals, the second signals, the first read signals and the second read signals to calculate a compensation gain of the each row. ### Claim 9 (depends on 1) A display device comprising the pixel correction circuit of claim 1. ### Claim 10 A pixel correction circuit comprising: a signal input circuit; a follower; and a reading circuit; wherein the signal input circuit is configured to apply a first signal and a second signal to the follower in a correction mode; wherein an input terminal of the follower is coupled to the signal input circuit; the follower is configured to receive the first signal and the second signal sequentially, output a first follow-up signal dependent on the first signal when receiving the first signal, and output a second follow-up signal dependent on the second signal when receiving the second signal; wherein the reading circuit is coupled to an output terminal of the follower; the reading circuit reads the first follow-up signal and then generates a first read signal, and reads the second follow-up signal and then generates a second read signal; and wherein the reading circuit uses the first signal, the second signal, the first read signal and the second read signal to calculate a compensation gain, thereby enabling the reading circuit to perform compensation correction based on the compensation gain, wherein the signal input circuit includes: a first signal receiving terminal configured to receive the first signal; a second signal receiving terminal configured to receive the second signal; a switching circuit; and a mode selection circuit; wherein the switching circuit includes a first input terminal, a second input terminal and an output terminal; a first path is defined between the first input terminal and the output terminal of the switching circuit; a second path is defined between the second input terminal and the output terminal of the switching circuit; the first input terminal of the switching circuit is coupled to the first signal receiving terminal; the second input terminal of the switching circuit is coupled to the second signal receiving terminal; wherein the mode selection circuit is coupled to the output terminal of the switching circuit; the mode selection circuit is further coupled to the input terminal of the follower; the mode selection circuit is configured to enable the switching circuit to be coupled with the follower in the correction mode; and wherein when the first path is switched on, the follower receives the first signal; and when the second path is switched on, the follower receives the second signal. ### Claim 11 (depends on 10) The pixel correction circuit of claim 10, wherein the signal input circuit further includes a detection signal input terminal; the detection signal input terminal is configured to receive a detection signal; and the mode selection circuit is further coupled to the detection signal input terminal. ### Claim 12 (depends on 10) The pixel correction circuit of claim 10, wherein the follower includes a follower transistor; a control terminal of the follower transistor is taken as the input terminal of the follower and is coupled to the signal input circuit; a first terminal of the follower transistor is coupled to a first power supply; and a second terminal of the follower transistor is taken as the output terminal of the follower and is coupled to the reading circuit. ### Claim 13 (depends on 12) The pixel correction circuit of claim 12, wherein the reading circuit includes an amplifier; and the amplifier is coupled to the second terminal of the follower transistor. ### Claim 14 (depends on 12) The pixel correction circuit of claim 12, wherein the second terminal of the follower transistor is a source terminal. ### Claim 15 (depends on 12) The pixel correction circuit of claim 12, wherein the follower further includes a first transistor; a first terminal of the first transistor is coupled to the second terminal of the follower transistor; a second terminal of the first transistor is coupled to a second power supply; and a control terminal of the first transistor is coupled to a first transistor control terminal. ### Claim 16 (depends on 15) The pixel correction circuit of claim 15, wherein the reading circuit includes an amplifier, and the amplifier is coupled to the second terminal of the follower transistor and the first terminal of the first transistor. ### Claim 17 A pixel correction method comprising: outputting, by a follower, a first follow-up signal dependent on a first signal when the follower receives the first signal; reading, by a reading circuit, the first follow-up signal and then generating a first read signal; outputting, by the follower, a second follow-up signal dependent on a second signal when the follower receives the second signal; reading, by the reading circuit, the second follow-up signal and then generating a second read signal; and calculating a compensation gain according to the first signal, the second signal, the first read signal and the second read signal, thereby enabling the reading circuit to perform compensation correction based on the compensation gain, wherein the calculating a compensation gain according to the first signal, the second signal, the first read signal and the second read signal, includes: obtaining a first voltage difference of the first signal and the second signal; obtaining a second voltage difference of the first read signal and the second read signal; and taking a ratio of the first voltage difference to the second voltage difference as the compensation gain.