# US 12,217,673 B2 · Pixel circuit, driving method and display device

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- Number: US 12,217,673 B2
- Document ID: US12217673B2
- Status: Granted
- Kind: B2
- Application number: 17/783,241
- Filed: 2021-06-23
- Published: 2024-05-23
- Granted: 2025-02-04
- Earliest claimed: 2021-06-23
- 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: Yao Huang; Tianyi Cheng; Ming Hu; Weiyun Huang; Benlian Wang; Doyoung Kim; Long Ma
- Web page: https://patentgrep.com/patent/US12217673B2

## CPC

- G09G 3/3208: organic, e.g. using organic light-emitting diodes [OLED]
- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
- 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 2310/0251: Precharge or discharge of pixel before applying new pixel voltage
- G09G 2310/0262: The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
- 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 includes a light-emitting element, a driving circuit, a first light-emitting control circuit, a compensation control circuit and a resetting circuit. The resetting circuit is configured to write an initial voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal, the first light-emitting control circuit is configured to control the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal, and the compensation control circuit is configured to control the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of a first scanning signal.

## Claims

### Claim 1

A pixel circuit, comprising a light-emitting element, a driving circuit, a first light-emitting control circuit, a compensation control circuit and a resetting circuit; wherein a refresh display period of the pixel circuit comprises a refresh resetting stage, and at least one display-maintaining period comprising a resetting-maintaining stage is set after the refresh display period; wherein,
the resetting circuit is electrically connected to a first light-emitting control line, an initial voltage terminal and a first electrode of the light-emitting element, and configured to write an initial voltage at the initial voltage terminal into the first electrode of the light-emitting element under the control of a first light-emitting control signal from the first light-emitting control line;
the first light-emitting control circuit is electrically connected to a second light-emitting control line, the first electrode of the light-emitting element and a first terminal of the driving circuit, and configured to control the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal from the second light-emitting control line;
the compensation control circuit is electrically connected to a first scanning line, a control terminal of the driving circuit and the first terminal of the driving circuit, and configured to control the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of a first scanning signal from the first scanning line;
the driving circuit is configured to control the generation of a driving current for driving the light-emitting element to emit light under the control of a potential at the control terminal of the driving circuit; and
a second electrode of the light-emitting element is electrically connected to a first voltage terminal;
wherein,
the resetting circuit is configured to write, within the refresh resetting stage, a first resetting voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal;
the first light-emitting control circuit is configured to control, within the refresh resetting stage, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal;
the compensation control circuit is configured to control, within the refresh resetting stage, the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of the first scanning signal, to write the first resetting voltage into the control terminal of the driving circuit;
the resetting circuit is further configured to write, within the resetting-maintaining stage, a second resetting voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal;
the first light-emitting control circuit is further configured to control, within the resetting-maintaining stage, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal, to write the second resetting voltage into the first terminal of the driving circuit;
the compensation control circuit is further configured to control, within the resetting-maintaining stage, the control terminal of the driving circuit to be electrically disconnected from the first terminal of the driving circuit under the control of the first scanning signal.

### Claim 2 (depends on 1)

The pixel circuit according to claim 1, further comprising a second light-emitting control circuit, a data written-in circuit and an energy storage circuit;
the second light-emitting control circuit is electrically connected to the first light-emitting control line, a second voltage terminal and a second terminal of the driving circuit, and configured to control the second voltage terminal to be electrically connected to the second terminal of the driving circuit under the control of the first light-emitting control signal;
the data written-in circuit is electrically connected to a second scanning line, a data line and the second terminal of the driving circuit, and configured to write a data voltage from the data line into the second terminal of the driving circuit under the control of a second scanning signal from the second scanning line; and
the energy storage circuit is electrically connected to the control terminal of the driving circuit, and configured to store an electrical energy.

### Claim 3 (depends on 1)

The pixel circuit according to claim 1, wherein the resetting circuit comprises a first transistor, the compensation control circuit comprises a second transistor, the first light-emitting control circuit comprises a third transistor, and the driving circuit comprises a driving transistor;
a control electrode of the first transistor is electrically connected to the first light-emitting control line, a first electrode of the first transistor is electrically connected to the initial voltage terminal, and a second electrode of the first transistor is electrically connected to the first electrode of the light-emitting element;
a control electrode of the second transistor is electrically connected to the first scanning line, a first electrode of the second transistor is electrically connected to the control terminal of the driving circuit, and a second electrode of the second transistor is electrically connected to the first electrode of the driving circuit;
a control electrode of the third transistor is electrically connected to the second light-emitting control line, a first electrode of the third transistor is electrically connected to the first terminal of the driving circuit, and a second electrode of the third transistor is electrically connected to the first electrode of the light-emitting element; and
a gate electrode of the driving transistor is electrically connected to the control terminal of the driving circuit, a first electrode of the driving transistor is electrically connected to the first terminal of the driving circuit, and a second electrode of the driving transistor is electrically connected to the second terminal of the driving circuit.

### Claim 4 (depends on 3)

The pixel circuit according to claim 3, wherein the first transistor and the second transistor are each an n-type transistor, and the driving transistor and the third transistor are each a p-type transistor.

### Claim 5 (depends on 2)

The pixel circuit according to claim 2, wherein the energy storage circuit comprises a storage capacitor, a first terminal of the storage capacitor is electrically connected to the control terminal of the driving circuit, and a second terminal of the storage capacitor is electrically connected to the second voltage terminal.

### Claim 6 (depends on 2)

The pixel circuit according to claim 2, wherein the data written-in circuit comprises a fourth transistor, and the second light-emitting control circuit comprises a fifth transistor;
a control electrode of the fourth transistor is electrically connected to the second scanning line, a first electrode of the fourth transistor is electrically connected to the data line, and a second electrode of the fourth transistor is electrically connected to the second terminal of the driving circuit; and
a control electrode of the fifth transistor is electrically connected to the first light-emitting control line, a first electrode of the fifth transistor is electrically connected to the second voltage terminal, and a second electrode of the fifth transistor is electrically connected to the second terminal of the driving circuit.

### Claim 7 (depends on 6)

The pixel circuit according to claim 6, wherein the fourth transistor and the fifth transistor are each a p-type transistor.

### Claim 8 (depends on 1)

The pixel circuit according to claim 1, wherein the light-emitting element is an organic light emitting diode, the first electrode of the light-emitting element is an anode of the organic light emitting diode, and the second electrode of the light-emitting element is a cathode of the organic light emitting diode.

### Claim 9 (depends on 1)

A driving method for the pixel circuit according to claim 1, the pixel circuit being applied to a display panel, a refresh display period comprising a refresh resetting stage, and the driving method comprising:
within the refresh resetting stage, writing, by the resetting circuit, a first resetting voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal, controlling, by the first light-emitting control circuit, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal, and controlling, by the compensation control circuit, the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of the first scanning signal, to write the first resetting voltage into the control terminal of the driving circuit.

### Claim 10 (depends on 9)

The driving method according to claim 9, wherein the refresh display period further comprises a charging stage and a refresh light-emitting stage after the refresh resetting stage, the pixel circuit further comprises a data written-in circuit and a second light-emitting control circuit, and the driving method further comprises:
within the charging stage, writing, by the data written-in circuit, the data voltage from the data line into the second terminal of the driving circuit under the control of a second scanning signal, and controlling, by the compensation control circuit, the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of the first scanning signal, to charge the energy storage circuit via the data voltage; and
within the refresh light-emitting stage, controlling, by the first light-emitting control circuit, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of the second light-emitting control signal, controlling, by the second light-emitting control circuit, the second voltage terminal to be electrically connected to the second terminal of the driving circuit under the control of the first light-emitting control signal, and driving, by the driving circuit, the light-emitting element to emit light.

### Claim 11 (depends on 10)

The driving method according to claim 10, wherein the display-maintaining period comprises the resetting-maintaining stage and a light-emitting-maintaining stage arranged one after another, the driving method comprises:
within the resetting-maintaining stage, writing, by the resetting circuit, a second resetting voltage into the first electrode of the light-emitting element under the control of the first light-emitting control signal; and
within the light-emitting-maintaining stage, controlling, by the first light-emitting control circuit, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of the second light-emitting control signal, controlling, by the second light-emitting control circuit, the second voltage terminal to be electrically connected to the second terminal of the driving circuit under the control of the first light-emitting control signal, and driving, by the driving circuit, the light-emitting element to emit light.

### Claim 12 (depends on 10)

The driving method according to claim 10, further comprising:
detecting a display brightness range of the display panel, and in a case that a maximum brightness value corresponding to the display brightness range is less than or equal to a predetermined brightness value, increasing a frequency of the first light-emitting control signal, to enable the frequency of the first light-emitting control signal to be greater than a predetermined frequency.

### Claim 13 (depends on 9)

The driving method according to claim 9, further comprising: increasing duration of the refresh resetting stage, to enable the duration of the refresh resetting stage to be greater than a predetermined time period.

### Claim 14 (depends on 11)

The driving method according to claim 11, further comprising: controlling the second resetting voltage to be less than the first resetting voltage.

### Claim 15

A display device comprising a pixel circuit, wherein the pixel circuit comprises a light-emitting element, a driving circuit, a first light-emitting control circuit, a compensation control circuit and a resetting circuit; wherein a refresh display period of the pixel circuit comprises a refresh resetting stage, and at least one display-maintaining period comprising a resetting-maintaining stage is set after the refresh display period; wherein,
the resetting circuit is electrically connected to a first light-emitting control line, an initial voltage terminal and a first electrode of the light-emitting element, and configured to write an initial voltage at the initial voltage terminal into the first electrode of the light-emitting element under the control of a first light-emitting control signal from the first light-emitting control line;
the first light-emitting control circuit is electrically connected to a second light-emitting control line, the first electrode of the light-emitting element and a first terminal of the driving circuit, and configured to control the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal from the second light-emitting control line;
the compensation control circuit is electrically connected to a first scanning line, a control terminal of the driving circuit and the first terminal of the driving circuit, and configured to control the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of a first scanning signal from the first scanning line;
the driving circuit is configured to control the generation of a driving current for driving the light-emitting element to emit light under the control of a potential at the control terminal of the driving circuit; and
a second electrode of the light-emitting element is electrically connected to a first voltage terminal;
wherein,
the resetting circuit is configured to write, within the refresh resetting stage, a first resetting voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal;
the first light-emitting control circuit is configured to control, within the refresh resetting stage, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal;
the compensation control circuit is configured to control, within the refresh resetting stage, the control terminal of the driving circuit to be electrically connected to the first terminal of the driving circuit under the control of the first scanning signal, to write the first resetting voltage into the control terminal of the driving circuit;
the resetting circuit is further configured to write, within the resetting-maintaining stage, a second resetting voltage into the first electrode of the light-emitting element under the control of a first light-emitting control signal;
the first light-emitting control circuit is further configured to control, within the resetting-maintaining stage, the first electrode of the light-emitting element to be electrically connected to the first terminal of the driving circuit under the control of a second light-emitting control signal, to write the second resetting voltage into the first terminal of the driving circuit;
the compensation control circuit is further configured to control, within the resetting-maintaining stage, the control terminal of the driving circuit to be electrically disconnected from the first terminal of the driving circuit under the control of the first scanning signal.

### Claim 16 (depends on 15)

The display device according to claim 15, further comprising a second light-emitting control circuit, a data written-in circuit and an energy storage circuit;
the second light-emitting control circuit is electrically connected to the first light-emitting control line, a second voltage terminal and a second terminal of the driving circuit, and configured to control the second voltage terminal to be electrically connected to the second terminal of the driving circuit under the control of the first light-emitting control signal;
the data written-in circuit is electrically connected to a second scanning line, a data line and the second terminal of the driving circuit, and configured to write a data voltage from the data line into the second terminal of the driving circuit under the control of a second scanning signal from the second scanning line; and
the energy storage circuit is electrically connected to the control terminal of the driving circuit, and configured to store an electrical energy.

### Claim 17 (depends on 15)

The display device according to claim 15, wherein the resetting circuit comprises a first transistor, the compensation control circuit comprises a second transistor, the first light-emitting control circuit comprises a third transistor, and the driving circuit comprises a driving transistor;
a control electrode of the first transistor is electrically connected to the first light-emitting control line, a first electrode of the first transistor is electrically connected to the initial voltage terminal, and a second electrode of the first transistor is electrically connected to the first electrode of the light-emitting element;
a control electrode of the second transistor is electrically connected to the first scanning line, a first electrode of the second transistor is electrically connected to the control terminal of the driving circuit, and a second electrode of the second transistor is electrically connected to the first electrode of the driving circuit;
a control electrode of the third transistor is electrically connected to the second light-emitting control line, a first electrode of the third transistor is electrically connected to the first terminal of the driving circuit, and a second electrode of the third transistor is electrically connected to the first electrode of the light-emitting element; and
a gate electrode of the driving transistor is electrically connected to the control terminal of the driving circuit, a first electrode of the driving transistor is electrically connected to the first terminal of the driving circuit, and a second electrode of the driving transistor is electrically connected to the second terminal of the driving circuit.

### Claim 18 (depends on 17)

The display device according to claim 17, wherein the first transistor and the second transistor are each an n-type transistor, and the driving transistor and the third transistor are each a p-type transistor.

### Claim 19 (depends on 16)

The display device according to claim 16, wherein the energy storage circuit comprises a storage capacitor, a first terminal of the storage capacitor is electrically connected to the control terminal of the driving circuit, and a second terminal of the storage capacitor is electrically connected to the second voltage terminal.

### Claim 20 (depends on 16)

The display device according to claim 16, wherein the data written-in circuit comprises a fourth transistor, and the second light-emitting control circuit comprises a fifth transistor;
a control electrode of the fourth transistor is electrically connected to the second scanning line, a first electrode of the fourth transistor is electrically connected to the data line, and a second electrode of the fourth transistor is electrically connected to the second terminal of the driving circuit; and
a control electrode of the fifth transistor is electrically connected to the first light-emitting control line, a first electrode of the fifth transistor is electrically connected to the second voltage terminal, and a second electrode of the fifth transistor is electrically connected to the second terminal of the driving circuit.