PIXEL DRIVING CIRCUIT AND OLED DISPLAY APPARATUS

• US 20200135104A1
• Filed: 01/27/2018
• Published: 04/30/2020
• Est. Priority Date: 12/20/2017
• Status: Abandoned Application

• Current Assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Ltd.
• Original Assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Ltd.
• Inventors: HOU, Xueshun, LI, Guang
• Application Number:
  US15/754,050
• Publication Number:
  US 20200135104A1
• Time in Patent Office: Days
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: 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
• CPC Class Codes: G09G 2310/0216 Interleaved control phases for different scan lines in the same sub-field, e.g. initialization, addressing and sustaining in plasma displays that are not simultaneous for all scan lines
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: 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
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

A pixel driving circuit and organic light-emitting diode (OLED) display apparatus having the pixel driving circuit is provided. The pixel driving circuit with 6T1C pixel structure effectively compensates the threshold voltage of the driving transistor, which drives the OLED display apparatus, to prevent the current flows through the OLED from being correlated with the threshold voltage of the driving transistor, so that the poor display image caused due to the threshold voltage shifting of the driving transistor is eliminated.

Claims

1. A pixel driving circuit, comprising:

a reset module configured to receive a reset signal from a reset signal line and a reference voltage signal from a reference voltage line in a reset stage, and generate a potential reset signal in accordance with the reset signal and the reference voltage signal;

a threshold voltage compensate module configured to receive a scan signal from a scan line and a data signal from a data line in a threshold voltage compensate stage, and generate a threshold voltage compensate signal in accordance with a scan signal and the data signal;

a light-emitting drive module configured to receive the potential reset signal and perform a potential reset operation in accordance with the received potential reset signal in the reset stage, receive the threshold voltage compensate signal and perform a threshold voltage compensate operation in accordance with the received threshold voltage compensate signal in the threshold voltage compensate stage, receive an enable signal from an enable signal line and a power voltage signal from a power line in a light-emitting drive stage, and generate a light-emitting drive signal in accordance with the enable signal and the power voltage signal; and

an organic light-emitting diode (OLED) configured to receive the light-emitting drive signal and emit light in accordance with the light-emitting drive signal.

2. The pixel driving circuit according to claim 1, wherein the reset signal is kept at low potential in the reset stage;

the reset signal is kept at low potential for a predetermined time period and changed to high potential from low potential after the predetermined time period in the threshold voltage compensate stage; and

the reset signal is kept at high potential in the light-emitting drive stage;

the enable signal is kept at high potential in the reset stage and the threshold voltage compensate stage, and is kept at low potential in the light-emitting drive stage;

the scan signal is kept at high potential in the reset stage, kept at low potential in the threshold voltage compensate stage, and kept at high potential in the light-emitting drive stage.

3. The pixel driving circuit according to claim 1, wherein the reset module comprises a fourth transistor;

a gate electrode of the fourth transistor is connected to the reset signal line to receive the reset signal;

a first electrode of the fourth transistor is connected to the reference voltage line to receive the reference voltage signal; and

a second electrode of the fourth transistor is connected to a first node.

4. The pixel driving circuit according to claim 2, wherein the reset module comprises a fourth transistor;

a gate electrode of the fourth transistor is connected to the reset signal line to receive the reset signal;

a first electrode of the fourth transistor is connected to the reference voltage line to receive the reference voltage signal; and

a second electrode of the fourth transistor is connected to a first node.

5. The pixel driving circuit according to claim 3, wherein the fourth transistor is configured to be conducted in the reset stage;

the fourth transistor is configured to be conducted within the predetermined time period and terminated after the predetermined time period in the threshold voltage compensate stage; and

the fourth transistor is configured to be terminated in the light-emitting drive stage.

6. The pixel driving circuit according to claim 4, wherein the fourth transistor is configured to be conducted in the reset stage;

the fourth transistor is configured to be conducted within the predetermined time period and terminated after the predetermined time period in the threshold voltage compensate stage; and

the fourth transistor is configured to be terminated in the light-emitting drive stage.

7. The pixel driving circuit according to claim 3, wherein the threshold voltage compensate module comprises a second transistor, a third transistor and a capacitor;

a gate electrode of the second transistor is connected to the scan line to receive the scan signal;

a first electrode of the second transistor is connected to the data line to receive the data signal; and

a second electrode of the second transistor is connected to a first terminal of the capacitor,

a gate electrode of the third transistor is connected to the scan line to receive the scan signal;

a first electrode of the third transistor is connected to the first node; and

a second electrode of the third transistor is connected to a third node;

a second terminal of the capacitor is connected to the first node.

8. The pixel driving circuit according to claim 4, wherein the threshold voltage compensate module comprises a second transistor, a third transistor and a capacitor;

a gate electrode of the second transistor is connected to the scan line to receive the scan signal;

a first electrode of the second transistor is connected to the data line to receive the data signal; and

a second electrode of the second transistor is connected to a first terminal of the capacitor,

a gate electrode of the third transistor is connected to the scan line to receive the scan signal;

a first electrode of the third transistor is connected to the first node; and

a second electrode of the third transistor is connected to a third node;

a second terminal of the capacitor is connected to the first node.

9. The pixel driving circuit according to claim 7, wherein the second transistor and the third transistor are configured to be terminated in the reset stage;

the second transistor and the third transistor are configured to be conducted in the threshold voltage compensate stage; and

the second transistor and the third transistor are configured to be terminated in the light-emitting drive stage.

10. The pixel driving circuit according to claim 8, wherein the second transistor and the third transistor are configured to be terminated in the reset stage;

the second transistor and the third transistor are configured to be conducted in the threshold voltage compensate stage; and

the second transistor and the third transistor are configured to be terminated in the light-emitting drive stage.

11. The pixel driving circuit according to claim 7, wherein the light-emitting drive module comprises a first transistor, a fifth transistor and a sixth transistor;

a gate electrode of the first transistor is connected to the first node, a first electrode of the first transistor is connected to a second node, the power line is connected to the second node, and a second electrode of the first transistor is connected to the third node;

a gate electrode of the fifth transistor is connected to the enable signal line to receive the enable signal;

a first electrode of the fifth transistor is connected to the second node; and

a second electrode of the fifth transistor is connected to the first terminal of the capacitor;

a gate electrode of the sixth transistor is connected to the enable signal line to receive the enable signal;

a first electrode of the sixth transistor is connected to the third node; and

a second electrode of the sixth transistor is connected to the OLED.

12. The pixel driving circuit according to claim 8, wherein the light-emitting drive module comprises a first transistor, a fifth transistor and a sixth transistor;

a gate electrode of the first transistor is connected to the first node, a first electrode of the first transistor is connected to a second node, the power line is connected to the second node, and a second electrode of the first transistor is connected to the third node;

a gate electrode of the fifth transistor is connected to the enable signal line to receive the enable signal;

a first electrode of the fifth transistor is connected to the second node; and

a second electrode of the fifth transistor is connected to the first terminal of the capacitor;

a gate electrode of the sixth transistor is connected to the enable signal line to receive the enable signal;

a first electrode of the sixth transistor is connected to the third node; and

a second electrode of the sixth transistor is connected to the OLED.

13. The pixel driving circuit according to claim 11, wherein the first transistor is configured to be terminated in the reset stage;

the first transistor is configured to be conducted in the threshold voltage compensate stage; and

the first transistor is configured to be conducted in the light-emitting drive stage;

the fifth transistor and the sixth transistor are configured to be terminated in the reset stage;

the fifth transistor and the sixth transistor are configured to be terminated in the threshold voltage compensate stage; and

the fifth transistor and the sixth transistor are configured to be conducted in the light-emitting drive stage.

14. The pixel driving circuit according to claim 12, wherein the first transistor is configured to be terminated in the reset stage;

the first transistor is configured to be conducted in the threshold voltage compensate stage; and

the first transistor is configured to be conducted in the light-emitting drive stage;

the fifth transistor and the sixth transistor are configured to be terminated in the reset stage;

the fifth transistor and the sixth transistor are configured to be terminated in the threshold voltage compensate stage; and

the fifth transistor and the sixth transistor are configured to be conducted in the light-emitting drive stage.

15. The pixel driving circuit according to claim 11, wherein each of the first to sixth transistors is p channel transistor.

16. The pixel driving circuit according to claim 12, wherein each of the first to sixth transistors is p channel transistor.

17. An organic light-emitting diode display apparatus comprising a pixel driving circuit of claim 1.