# US 12,112,689 B2 · Display panel, driving method, and display device

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- Number: US 12,112,689 B2
- Document ID: US12112689B2
- Status: Granted
- Kind: B2
- Application number: 18/071,449
- Filed: 2022-11-29
- Published: 2023-03-23
- Granted: 2024-10-08
- Earliest claimed: 2020-10-20
- Assignees: Xiamen Tianma Micro-Electronics Co., Ltd.
- Applicants: Xiamen Tianma Micro-Electronics Co., Ltd.
- Inventors: Jieliang Li; Jiaxian Liu
- Web page: https://patentgrep.com/patent/US12112689B2

## CPC

- G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED]
- G09G 3/2092: {Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto (suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165)}
- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 2300/0417: Special arrangements specific to the use of low carrier mobility technology
- 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 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 2310/0278: Details of driving circuits arranged to drive both scan and data electrodes
- G09G 2320/0238: Improving the black level
- G09G 2320/043: Preventing or counteracting the effects of ageing
- 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 display panel includes a pixel circuit and a light-emitting element. The pixel circuit includes a data-writing module, a driving module, and a compensation module. The driving module is configured to provide a driving current for the light-emitting element, wherein the driving module includes a driving transistor, and the driving transistor is an NMOS transistor. The data-writing module is configured to selectively provide a data signal for the driving module. The compensation module is configured to compensate a threshold voltage of the driving transistor. An operational process of the pixel circuit includes a bias stage. In the bias stage, the compensation module is turned off, the driving transistor receives a bias signal, and the bias signal is configured to adjust a bias state of the driving transistor.

## Claims

### Claim 1

A display panel, comprising a pixel circuit and a light-emitting element, wherein:
the pixel circuit includes a data-writing module, a driving module, and a compensation module;
the driving module is configured to provide a driving current for the light-emitting element, wherein the driving module includes a driving transistor, and the driving transistor is an NMOS transistor and is a double gate transistor that includes a first gate and a second gate, wherein the first gate is a control terminal of the driving transistor and the second gate is set to be electrically connected to an output terminal of the data-writing module;
the data-writing module is configured to selectively provide a data signal for the driving module; and
the compensation module is configured to compensate a threshold voltage of the driving transistor;
wherein:
the data-writing module is multiplexed as a bias module;
in one image frame of the display panel, an operational process of the pixel circuit includes a pre-stage when the light-emitting element does not emit light and a light-emitting stage when the light-emitting element emits light, wherein the pre-stage includes a bias stage and a data-writing stage;
in the bias stage, the compensation module is turned off, the driving transistor receives a bias signal through the data-writing module, and the bias signal is configured to adjust a bias state of the driving transistor; and
in the data-writing stage, the compensation module is turned on, and the driving transistor receives the data signal through the same data-writing module.

### Claim 2 (depends on 1)

The display panel according to claim 1, wherein:
in the data-writing stage, a data signal input terminal connected to the data-writing module receives the data signal, and in the bias stage, the data signal input terminal receives the bias signal;
in the data-writing stage, each of the data-writing module, the driving module, and the compensation module is turned on, and the driving transistor receives the data signal; and
in the bias stage, the compensation module is turned off, the data-writing module and the driving module are turned on, and the bias signal is written into the driving transistor.

### Claim 3 (depends on 2)

The display panel according to claim 2, wherein:
the pixel circuit includes k rows of light-emitting elements;
during the operational process of the pixel circuit corresponding to the light-emitting element in an i-th row, in the bias stage, the data-writing module is turned on, and the bias signal written into a second terminal of the driving transistor is a present data signal on a data signal line connected to the data signal input terminal; and
the present data signal is the data signal of the pixel circuit corresponding to the light- emitting element in a j-th row, written in the data-writing stage,
wherein:
k≥1, 1≤i≤k, and 1≤j≤k.

### Claim 4 (depends on 1)

The display panel according to claim 1, wherein:
at the end of the bias stage, the data-writing module remains turned on, the compensation module is turned on, and the pixel circuit enters the data-writing stage.

### Claim 5 (depends on 1)

The display panel according to claim 1, wherein:
at the end of the bias stage, the data-writing module is turned off, and the pixel circuit enters a fifth interval stage; and
at the end of the fifth interval stage, the data-writing module and compensation module both are turned on, and the pixel circuit enters the data-writing stage.

### Claim 6 (depends on 5)

The display panel according to claim 5, wherein:
a duration of the fifth interval stage is shorter than a duration of the bias stage; or
the duration of the fifth interval stage is shorter than a duration of the data-writing stage.

### Claim 7

A method of driving a display panel, wherein:
the display panel includes a pixel circuit and a light-emitting element;
the pixel circuit includes a data-writing module, a driving module, and a compensation module;
the driving module is configured to provide a driving current for the light-emitting element, wherein the driving module includes a driving transistor, and the driving transistor is an NMOS transistor and is a double gate transistor that includes a first gate and a second gate, wherein the first gate is a control terminal of the driving transistor and the second gate is set to be electrically connected to an output terminal of the data-writing module;
the data-writing module is configured to selectively provide a data signal for the driving module; and
the compensation module is configured to compensate a threshold voltage of the driving transistor;
wherein:
in one image frame of the display panel, an operational process of the pixel circuit includes a pre-stage when the light-emitting element does not emit light and a light-emitting stage when the light-emitting element emits light, wherein the pre-stage includes a bias stage and a data-writing stage;
in the bias stage, the compensation module is turned off, the driving transistor receives a bias signal through the data-writing module, and the bias signal is configured to adjust a bias state of the driving transistor; and
in the data-writing stage, the compensation module is turned on, and the driving transistor receives the data signal through the same data-writing module.