# US 2021/0241664 A1 · Method of detecting threshold voltage shift and threshold votage shift detection device

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- Number: US 2021/0241664 A1
- Document ID: US20210241664A1
- Status: Published application
- Kind: A1
- Application number: 17/040,913
- Filed: 2020-04-21
- Published: 2021-08-05
- Earliest claimed: 2019-05-30
- Assignees: Hefei Xinsheng Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Hefei Xinsheng Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Inventors: Guangyao LI; Dongfang WANG; Jun WANG; Haitao WANG; Chaowei HAO; Bo FENG; Rong LIU; Wei CAI; Biao LUO; Xuechao SUN; Xuehai GUI; Qibin LIANG; Yanfei WAN; Jin SU
- Web page: https://patentgrep.com/patent/US20210241664A1

## CPC

- 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 3/3225: using an active matrix
- G09G 2300/0426: Layout of electrodes and connections
- G09G 2300/0809: Several active elements per pixel in active matrix panels
- G09G 2320/0295: by monitoring each display pixel
- G09G 2320/041: Temperature compensation
- G09G 2320/0666: for control of colour parameters, e.g. colour temperature
- G09G 2330/02: Details of power systems and of start or stop of display operation
- G09G 2330/12: Test circuits or failure detection circuits included in a display system, as permanent part thereof
- 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 of detecting threshold voltage shift and a threshold voltage shift detection device are provided. The method is applied to a pixel driving circuit which I is electrically coupled to a control line, a voltage line and a detection node, respectively. The method includes: in a detection cycle including a setting phase and a detection phase, in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state; in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node.

## Claims

### Claim 1

A method of detecting threshold voltage shift, applied to a pixel driving circuit which is electrically coupled to a control line, a voltage line and a detection node, respectively, comprising: in a detection cycle including a setting phase and a detection phase,
in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state;
in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the pixel driving circuit includes a data writing circuit, a driving circuit and a compensation control circuit; the control line includes a gate line and a compensation control line; the voltage line includes a power supply voltage line, a data line, and an external compensation line;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes: in the setting phase, controlling a data writing transistor included in the data writing circuit, a driving transistor included in the driving circuit, or a compensation control transistor included in the compensation control circuit to be in the biased state.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the pixel driving circuit includes a data writing circuit, a driving circuit and a compensation control circuit; the control line includes a gate line and the compensation control line; the voltage line includes a power supply voltage line, a data line and an external compensation line;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes:
in the detection phase, providing a corresponding gate driving voltage signal to the gate line, providing a corresponding data voltage to the data line, providing a corresponding power supply voltage to the power supply voltage line, and determining a threshold voltage shift state of a data writing transistor included in the data writing circuit according to the electric potential of the detection node; or, providing a corresponding compensation control voltage signal to the compensation control line, providing a corresponding compensation voltage signal to the external compensation line, and determining a threshold voltage shift state of a compensation control transistor included in the compensation control circuit according to the electric potential of the detection node; or, providing a corresponding power supply voltage to the power supply voltage line, providing a corresponding gate driving voltage signal to the gate line, providing a corresponding data voltage to the data line, and determining a threshold voltage shift state of a driving transistor included in the driving circuit according to the electric potential of the detection node.

### Claim 4 (depends on 2)

The method according to claim 2, wherein a control electrode of the data writing transistor is electrically coupled to the gate line; a first electrode of the data writing transistor is electrically coupled to the data line; and a second electrode of the data writing transistor is electrically coupled to a control terminal of the driving circuit; the pixel driving circuit further includes an energy storage circuit; a first terminal of the energy storage circuit is electrically coupled to the control terminal of the driving circuit; a second terminal of the energy storage circuit is electrically coupled to the detection node;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, controlling providing a first voltage signal to the data line and providing a positive voltage signal or a negative voltage signal to the gate line, to control the data writing transistor to be in a forward biased state or a reverse biased state.

### Claim 5 (depends on 2)

The method according to claim 2, wherein the detection phase includes a first detection period, a second detection period and a third detection period that are sequentially set;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes:
in the detection phase, providing a preset first data voltage to the data line, and providing a preset first power supply voltage to the power supply voltage line;
in the first detection period, providing a first gate driving voltage signal to the gate line;
in the second detection period, providing a second gate driving voltage signal to the gate line;
in the third detection period, providing the first gate driving voltage signal to the gate line; after a first preset period, detecting the electric potential of the detection node, and determining the threshold voltage shift state of the data writing transistor according to the electric potential of the detection node.

### Claim 6 (depends on 2)

The method according to claim 2, wherein a control electrode of the compensation control transistor is electrically coupled to the compensation control line, a first electrode of the compensation control transistor is electrically coupled to the detection node, and a second electrode of the compensation control transistor is electrically coupled to the external compensation line;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, controlling providing a second voltage signal to the external compensation line and providing a positive voltage signal or a negative voltage signal to the compensation control line, to control the compensation control transistor to be in a forward biased state or a reverse biased state.

### Claim 7 (depends on 2)

The method according to claim 2, wherein the detection phase includes a first detection period, a second detection period and a third detection period that are sequentially set;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes:
in the detection phase, providing a preset compensation voltage signal to the external compensation line;
in the first detection period, providing a first compensation control voltage signal to the compensation control line;
in the second detection period, providing a second compensation control voltage signal to the compensation control line;
in the third detection period, providing the first compensation control voltage signal to the compensation control line; and after a second preset period, detecting the electric potential of the detection node, and determining the threshold voltage shift state of the compensation control transistor according to the electric potential of the detection node.

### Claim 8 (depends on 2)

The method according to claim 2, wherein a control electrode of the driving transistor is a control terminal of the driving circuit; a first electrode of the driving transistor is electrically coupled to the power supply voltage line; a second electrode of the driving transistor is electrically coupled to the detection node;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, providing a preset second data voltage to the data line and providing a third gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control writing the second data voltage into the control electrode of the driving transistor, and providing a preset second power supply voltage to the power supply voltage line to control the driving transistor to be in the biased state.

### Claim 9 (depends on 2)

The method according to claim 2, wherein a control electrode of the driving transistor is a control terminal of the driving circuit; a first electrode of the driving transistor is electrically coupled to the power supply voltage line; a second electrode of the driving transistor is electrically coupled to the detection node; the setting phase includes at least one resetting sub-phase, and the resetting sub-phase includes a first setting period, a second setting period and a third setting period that are sequentially set;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, providing a preset third data voltage to the data line, and providing a preset third power supply voltage to the power supply voltage line;
in the first setting period, providing a fourth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control writing the third data voltage to the control electrode of the driving transistor;
in the second setting period, providing a fifth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor;
in the third setting period, providing a third voltage signal to the gate line;
wherein a difference value between a voltage value of the third voltage signal and 0V is within a preset voltage difference range;
wherein a difference value between a duration of the first setting period and a duration of the second setting period is within a preset period difference range.

### Claim 10 (depends on 2)

The method according to claim 2, wherein the detection phase includes at least one detection sub-phase; the detection sub-phase includes a first detection period and a second detection period; the first detection period includes a first detection sub-period and a second detection sub-period; the second detection period includes a third detection sub-period and a fourth detection sub-period;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes: in the detection phase, providing a preset fourth power supply voltage to the power supply voltage line;
in the first detection sub-period, providing a fourth data voltage to the data line and providing a sixth gate driving voltage signal to the gate line, to control the data writing circuit to write the fourth data voltage into a control electrode of the driving transistor;
in the second detection sub-period, providing the fourth data voltage to the data line and providing a seventh gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor; after a third preset period, detecting an electric potential of the detection node, thereby obtaining a first detection electric potential;
in the third detection sub-period, providing a fifth data voltage to the data line and providing an eighth gate driving voltage signal to the gate line, to control the data writing circuit to write the fourth data voltage to the control electrode of the driving transistor;
in the fourth detection sub-period, providing the fifth data voltage to the data line and providing a ninth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor; after a fourth preset period, detecting an electric potential of the detection node, thereby obtaining a second detection electric potential;
according to a sum of the first detection electric potential and the second detection electric potential, determining a threshold shift state of the driving transistor.

### Claim 11

A threshold voltage shift detection device, applied to a pixel driving circuit which is electrically connected to a control line, a voltage line and a detection node, respectively, comprising a setter and a detector;
wherein the setter is configured to, in a setting phase, control a transistor included in the pixel driving circuit to be in a biased state;
the detector is configured to, in a detection phase, provide a preset control voltage signal to the control line, provide a preset voltage signal to the voltage line, and determine a threshold voltage shift state of the transistor according to an electric potential of the detection node.

### Claim 12 (depends on 3)

The method according to claim 3, wherein a control electrode of the data writing transistor is electrically coupled to the gate line; a first electrode of the data writing transistor is electrically coupled to the data line; and a second electrode of the data writing transistor is electrically coupled to a control terminal of the driving circuit; the pixel driving circuit further includes an energy storage circuit; a first terminal of the energy storage circuit is electrically coupled to the control terminal of the driving circuit; a second terminal of the energy storage circuit is electrically coupled to the detection node;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, controlling providing a first voltage signal to the data line and providing a positive voltage signal or a negative voltage signal to the gate line, to control the data writing transistor to be in a forward biased state or a reverse biased state.

### Claim 13 (depends on 3)

The method according to claim 3, wherein the detection phase includes a first detection period, a second detection period and a third detection period that are sequentially set;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes:
in the detection phase, providing a preset first data voltage to the data line, and providing a preset first power supply voltage to the power supply voltage line;
in the first detection period, providing a first gate driving voltage signal to the gate line;
in the second detection period, providing a second gate driving voltage signal to the gate line;
in the third detection period, providing the first gate driving voltage signal to the gate line; after a first preset period, detecting the electric potential of the detection node, and determining the threshold voltage shift state of the data writing transistor according to the electric potential of the detection node.

### Claim 14 (depends on 3)

The method according to claim 3, wherein a control electrode of the compensation control transistor is electrically coupled to the compensation control line, a first electrode of the compensation control transistor is electrically coupled to the detection node, and a second electrode of the compensation control transistor is electrically coupled to the external compensation line;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, controlling providing a second voltage signal to the external compensation line and providing a positive voltage signal or a negative voltage signal to the compensation control line, to control the compensation control transistor to be in a forward biased state or a reverse biased state.

### Claim 15 (depends on 3)

The method according to claim 3, wherein the detection phase includes a first detection period, a second detection period and a third detection period that are sequentially set;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes:
in the detection phase, providing a preset compensation voltage signal to the external compensation line;
in the first detection period, providing a first compensation control voltage signal to the compensation control line;
in the second detection period, providing a second compensation control voltage signal to the compensation control line;
in the third detection period, providing the first compensation control voltage signal to the compensation control line; and after a second preset period, detecting the electric potential of the detection node, and determining the threshold voltage shift state of the compensation control transistor according to the electric potential of the detection node.

### Claim 16 (depends on 3)

The method according to claim 3, wherein a control electrode of the driving transistor is a control terminal of the driving circuit; a first electrode of the driving transistor is electrically coupled to the power supply voltage line; a second electrode of the driving transistor is electrically coupled to the detection node;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, providing a preset second data voltage to the data line and providing a third gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control writing the second data voltage into the control electrode of the driving transistor, and providing a preset second power supply voltage to the power supply voltage line to control the driving transistor to be in the biased state.

### Claim 17 (depends on 3)

The method according to claim 3, wherein a control electrode of the driving transistor is a control terminal of the driving circuit; a first electrode of the driving transistor is electrically coupled to the power supply voltage line; a second electrode of the driving transistor is electrically coupled to the detection node; the setting phase includes at least one resetting sub-phase, and the resetting sub-phase includes a first setting period, a second setting period and a third setting period that are sequentially set;
wherein in the setting phase, controlling a transistor included in the pixel driving circuit to be in a biased state, includes:
in the setting phase, providing a preset third data voltage to the data line, and providing a preset third power supply voltage to the power supply voltage line;
in the first setting period, providing a fourth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control writing the third data voltage to the control electrode of the driving transistor;
in the second setting period, providing a fifth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor;
in the third setting period, providing a third voltage signal to the gate line;
wherein a difference value between a voltage value of the third voltage signal and 0V is within a preset voltage difference range;
wherein a difference value between a duration of the first setting period and a duration of the second setting period is within a preset period difference range.

### Claim 18 (depends on 3)

The method according to claim 3, wherein the detection phase includes at least one detection sub-phase; the detection sub-phase includes a first detection period and a second detection period; the first detection period includes a first detection sub-period and a second detection sub-period; the second detection period includes a third detection sub-period and a fourth detection sub-period;
wherein in the detection phase, providing a preset control voltage signal to the control line, providing a preset voltage signal to the voltage line, and determining a threshold voltage shift state of the transistor according to an electric potential of the detection node, includes: in the detection phase, providing a preset fourth power supply voltage to the power supply voltage line;
in the first detection sub-period, providing a fourth data voltage to the data line and providing a sixth gate driving voltage signal to the gate line, to control the data writing circuit to write the fourth data voltage into a control electrode of the driving transistor;
in the second detection sub-period, providing the fourth data voltage to the data line and providing a seventh gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor; after a third preset period, detecting an electric potential of the detection node, thereby obtaining a first detection electric potential;
in the third detection sub-period, providing a fifth data voltage to the data line and providing an eighth gate driving voltage signal to the gate line, to control the data writing circuit to write the fourth data voltage to the control electrode of the driving transistor;
in the fourth detection sub-period, providing the fifth data voltage to the data line and providing a ninth gate driving voltage signal to the gate line, thereby enabling the data writing circuit to control the data line to be decoupled from the control electrode of the driving transistor; after a fourth preset period, detecting an electric potential of the detection node, thereby obtaining a second detection electric potential;
according to a sum of the first detection electric potential and the second detection electric potential, determining a threshold shift state of the driving transistor.