# US 11,443,694 B2 · Pixel circuit, method for driving the same, display panel and display device

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- Number: US 11,443,694 B2
- Document ID: US11443694B2
- Status: Granted
- Kind: B2
- Application number: 17/140,232
- Filed: 2021-01-04
- Published: 2021-04-29
- Granted: 2022-09-13
- Earliest claimed: 2018-08-30
- Assignees: Chengdu Boe Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Chengdu BOE Optoelectronics Technology Co., Ltd.; BOE Technology Group Co., Ltd.
- Inventors: Qian Li; Bing Zhang
- Web page: https://patentgrep.com/patent/US11443694B2

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element
- G09G 2230/00: Details of flat display driving waveforms
- G09G 2300/0452: Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
- 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 2310/06: Details of flat display driving waveforms
- G09G 2310/061: for resetting or blanking
- 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

A pixel circuit, a method for driving the same, a display panel and a display device are provided. The pixel circuit includes: a driving sub-circuit, a first light-emission controlling sub-circuit, a second light-emission controlling sub-circuit, an anode potential controlling sub-circuit, all of which operate in cooperation so that the pixel circuit drives a light-emitting element to emit light, where the second light-emission controlling sub-circuit provides voltage output by the driving sub-circuit to an anode of the light-emitting element in a light-emission period, and the anode potential controlling sub-circuit provides a signal of a first voltage signal terminal to the anode of the light-emitting element in a non-light-emission period.

## Claims

### Claim 1

A pixel circuit, comprising: a first light-emission controlling sub-circuit, a driving sub-circuit, and an anode potential controlling sub-circuit, wherein:
the first light-emission controlling sub-circuit is configured to provide a signal of a second voltage signal terminal to the driving sub-circuit under the control of a first control terminal;
the driving sub-circuit is configured to drive a light-emitting element to emit light, wherein a cathode of the light-emitting element is connected to a third voltage signal terminal; and
the anode potential controlling sub-circuit is configured to provide a signal of a fourth voltage signal terminal to an anode of the light-emitting element under the control of a second control terminal;
wherein in a light-emission period, the first light-emission controlling sub-circuit provides the signal of the second voltage signal terminal to the driving sub-circuit under the control of the first control terminal, to enable the driving sub-circuit output voltage to the anode of the light-emitting element, and in a non-light-emission period, the anode potential controlling sub-circuit provides the signal of the fourth voltage signal terminal to the anode of the light-emitting element under the control of the second control terminal;
wherein the non-light-emission period comprises a reset period and a data writing period, the signal of the second control terminal and the signal of the first control terminal are opposite level signals in phase in at least part time period of the reset period; and
the signal of the second control terminal and the signal of the first control terminal are opposite level signals in phase in at least part time period of the data writing period.

### Claim 2 (depends on 1)

The pixel circuit according to claim 1, wherein a time length of active level of the signal of the second control terminal is t, a time length of turn-off level of the signal of the first control terminal is m, m=c*t, 0.7<c<1.5.

### Claim 3 (depends on 1)

The pixel circuit according to claim 1, further comprising: a second light-emission controlling sub-circuit configured to provide voltage output by the driving sub-circuit to the anode of the light-emitting element under the control of the first control terminal in the light-emission period.

### Claim 4 (depends on 1)

The pixel circuit according to claim 1, further comprising: a resetting sub-circuit, a data writing sub-circuit, a capacitor sub-circuit; wherein:
the resetting sub-circuit is configured to provide a signal of a first voltage signal terminal to a control terminal of the driving sub-circuit under the control of a reset signal terminal in the reset period;
the data writing sub-circuit is configured to provide a data signal transmitted from a data signal terminal to the driving sub-circuit under the control of a scan signal terminal in the date writing period;
the driving sub-circuit is configured to drive the light-emitting element to emit light, under the control of a potential output by the resetting sub-circuit;
the capacitor sub-circuit is configured to maintain a stable voltage difference between the second voltage signal terminal and the control terminal of the driving sub-circuit.

### Claim 5 (depends on 4)

The pixel circuit according to claim 4, wherein the signal of the first voltage signal terminal is different from the signal of the fourth voltage signal terminal.

### Claim 6 (depends on 4)

The pixel circuit according to claim 4, wherein the signal of the first voltage signal terminal is V1, the signal of the fourth voltage signal terminal is V4, V4=a*V1, 2<a<10.

### Claim 7 (depends on 6)

The pixel circuit according to claim 6, wherein a=5.

### Claim 8 (depends on 4)

The pixel circuit according to claim 4, wherein the signal of the first voltage signal terminal is V1, the signal of the fourth voltage signal terminal is V4, a signal of the third voltage signal terminal is V3, V4=V1+b*V3, 0<b<2.

### Claim 9 (depends on 8)

The pixel circuit according to claim 8, wherein b=1.

### Claim 10

A pixel circuit, comprising: a resetting sub-circuit, a data writing sub-circuit, a driving sub-circuit, a first light-emission controlling sub-circuit, a second light-emission controlling sub-circuit, an anode potential controlling sub-circuit, a capacitor sub-circuit, and a light-emitting element, wherein:
the resetting sub-circuit is configured to provide a signal of a first voltage signal terminal to a control terminal of the driving sub-circuit under the control of a reset signal terminal;
the data writing sub-circuit is configured to provide a data signal transmitted from a data signal terminal to the driving sub-circuit under the control of a scan signal terminal;
the driving sub-circuit is configured to drive the light-emitting element to emit light, under the control of a potential output by the resetting sub-circuit, wherein a cathode of the light-emitting element is connected to a third voltage signal terminal;
the first light-emission controlling sub-circuit is configured to provide a signal of a second voltage signal terminal to the driving sub-circuit under the control of a first control terminal;
the capacitor sub-circuit is configured to maintain a stable voltage difference between the second voltage signal terminal and the control terminal of the driving sub-circuit;
the second light-emission controlling sub-circuit is configured to provide voltage output by the driving sub-circuit to an anode of the light-emitting element under the control of the first control terminal; and
the anode potential controlling sub-circuit is configured to provide a signal of a fourth voltage signal terminal to the anode of the light-emitting element under the control of a second control terminal, wherein the anode potential controlling sub-circuit comprises a sixth transistor, and wherein the sixth transistor has a gate connected with the second control terminal, a first electrode connected with the fourth voltage signal terminal, and a second electrode connected with the anode of the light-emitting element;
wherein in a light-emission period, the second light-emission controlling sub-circuit provides the voltage output by the driving sub-circuit to the anode of the light-emitting element under the control of the first control signal terminal, and in a non-light-emission period, the sixth transistor is turned on under the control of the second control terminal, and provides the signal of the fourth voltage signal terminal to the anode of the light-emitting element;
wherein the second control terminal is a different terminal from the scan signal terminal, and a signal of the first control terminal and a signal of the second control terminal are substantially opposite level signals in phase.

### Claim 11 (depends on 10)

The pixel circuit according to claim 10, wherein the signal of the first voltage signal terminal is different from the signal of the fourth voltage signal terminal.

### Claim 12 (depends on 11)

The pixel circuit according to claim 11, wherein the signal of the first voltage terminal and the signal of the fourth voltage signal terminal are negative voltages.

### Claim 13 (depends on 12)

The pixel circuit according to claim 12, wherein the signal of the first voltage signal terminal is greater than the signal of the fourth voltage signal terminal.

### Claim 14 (depends on 10)

The pixel circuit according to claim 10, wherein the signal of the first voltage signal terminal is V1, the signal of the fourth voltage signal terminal is V4, V4=a*V1, 2<a<10.

### Claim 15 (depends on 10)

The pixel circuit according to claim 10, wherein the signal of the first voltage signal terminal is V1, the signal of the fourth voltage signal terminal is V4, a signal of the third voltage signal terminal is V3, V4=V1+b*V3, 0<b<2.

### Claim 16 (depends on 10)

The pixel circuit according to claim 10, wherein a time length of active level of the signal of the second control terminal is t, a time length of turn-off level of the signal of the first control terminal is m, m=c*t, 0.7<c<1.5.

### Claim 17 (depends on 10)

A method for driving the pixel circuit according to claim 10, comprising:
in a reset period, providing, by the resetting sub-circuit, the signal of the first voltage signal terminal to the driving sub-circuit under the control of the reset signal terminal, and providing, by the anode potential controlling sub-circuit, the signal of the fourth voltage signal terminal to the anode of the light-emitting element under the control of the second control terminal;
in a data writing period, providing, by the data writing sub-circuit, the signal of the data signal terminal to the driving sub-circuit under the control of the scan signal terminal, maintaining, by the capacitor sub-circuit, a stable voltage difference between the control terminal of the driving sub-circuit and the second voltage signal terminal, and providing, by the anode potential controlling sub-circuit, the signal of the fourth voltage signal terminal to the anode of the light-emitting element under the control of the second control terminal; and
in a light-emission period, providing, by the first light-emission controlling sub-circuit, the signal of the second voltage signal terminal to the driving sub-circuit under the control of the first control terminal, maintaining, by the capacitor sub-circuit, a stable voltage difference between the control terminal of the driving sub-circuit and the second voltage signal terminal, to control the driving sub-circuit to provide a driving signal to the second light-emission controlling sub-circuit; and providing, by the second light-emission controlling sub-circuit, the potential output by the driving sub-circuit to the anode of the light-emitting element under the control of the first control terminal.

### Claim 18 (depends on 10)

A light-emitting diode display panel, comprising a plurality of sub-pixels arranged in a matrix, each of the sub-pixel comprises the pixel circuit according to claim 10.

### Claim 19 (depends on 18)

The light-emitting diode display panel according to claim 18, wherein the sub-pixels comprises a first sub-pixel and a second sub-pixel, the first sub-pixel and the second sub-pixel corresponding to light-emitting elements in different colors,
wherein a signal of a fourth voltage signal terminal in the pixel circuit of the first sub-pixel is different from a signal of a fourth voltage signal terminal in the pixel circuit of the second sub-pixel.

### Claim 20 (depends on 19)

The light-emitting diode display panel according to claim 19, wherein the first sub-pixel is a blue sub-pixel, the second sub-pixel is a green sub-pixel or red sub-pixel; the signal of the fourth voltage signal terminal in the pixel circuit of the first sub-pixel is greater than the signal of the fourth voltage signal terminal in the pixel circuit of the second sub-pixel.