# US 12,217,671 B2 · Pixel driving circuit, driving method thereof, and display panel

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- Number: US 12,217,671 B2
- Document ID: US12217671B2
- Status: Granted
- Kind: B2
- Application number: 17/756,647
- Filed: 2022-04-22
- Published: 2024-05-16
- Granted: 2025-02-04
- Earliest claimed: 2022-04-11
- Assignees: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
- Applicants: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
- Inventors: Wei Dou
- Web page: https://patentgrep.com/patent/US12217671B2

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3225: using an active matrix
- 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 2310/0248: Precharge or discharge of column electrodes before or after applying exact column voltages
- G09G 2310/0294: Details of sampling or holding circuits arranged for use in a driver for data electrodes
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- 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

The present disclosure provides a pixel driving circuit, a driving method thereof, and a display panel. A switching transistor and a sensing transistor are controlled with the same scanning line. In a detection stage, a voltage of a scanning signal line is adjusted to enable the sensing transistor to be turned on and the switching transistor to be turned off, so that a gate and a source of the driving transistor are in a floating state. A storage capacitor maintains a gate-source potential difference of the driving transistor to be stable, thereby it can accurately compensate for the mobility of the driving transistor.

## Claims

### Claim 1

A pixel driving circuit, comprising a scanning line, a data line, a sensing line, a reset line, a driving transistor, a switching transistor, a sensing transistor, a storage capacitor, and a reset switch, wherein a gate of the driving transistor is respectively connected to a drain of the switching transistor and a first terminal of the storage capacitor, a drain of the driving transistor is connected to an input terminal of a power supply, a source of the driving transistor is respectively connected to a drain of the sensing transistor and a second terminal of the storage capacitor, both a gate of the switching transistor and a gate of the sensing transistor are connected to the scanning line, a source of the switching transistor is connected to the data line, a source of the sensing transistor is connected to the sensing line, a first terminal of the reset switch is connected to the source of the sensing transistor, and a second terminal of the reset switch is connected to the reset line;
in a pre-charging stage, the reset switch is closed, and a first scanning voltage provided to the scanning line, a data voltage provided to the data line, and a reset voltage provided to the reset line enable both the switching transistor and the sensing transistor to be turned on; and
in a detection stage following the pre-charging stage, the reset switch is opened, a second scanning voltage provided to the scanning line enables the switching transistor to be turned off and the sensing transistor to be turned on, so that both the gate of the driving transistor and the source of the driving transistor are in a floating state.

### Claim 2 (depends on 1)

The pixel driving circuit of claim 1, further comprising a sampling switch and a processor, wherein a first terminal of the sampling switch is connected to the sensing line, and a second terminal of the sampling switch is connected to the processor.

### Claim 3 (depends on 2)

The pixel driving circuit of claim 2, wherein, in the detection stage, the driving transistor is turned on and the sampling switch is turned off.

### Claim 4 (depends on 2)

The pixel driving circuit of claim 2, wherein, in a sampling stage following the detection stage, the sampling switch is closed, the reset switch is opened, the switching transistor remains to be turned off, and both the driving transistor and the sensing transistor remains to be turned on.

### Claim 5 (depends on 1)

The pixel driving circuit of claim 1, wherein, in the case that the switching transistor is an N-type thin film transistor, the second scanning voltage is less than the first scanning voltage.

### Claim 6 (depends on 1)

The pixel driving circuit of claim 1, wherein, in the case that the switching transistor is a P-type thin film transistor, the second scanning voltage is greater than the first scanning voltage.