CN-121999710-A - Display device, pixel driving circuit, and control method of pixel driving circuit

CN121999710ACN 121999710 ACN121999710 ACN 121999710ACN-121999710-A

Abstract

The application relates to a display device, a pixel driving circuit and a control method of the pixel driving circuit. The pixel driving circuit comprises a voltage writing circuit, a voltage holding circuit, a voltage compensation circuit and a light emitting circuit, wherein the input end of the voltage writing circuit is connected with a pulse amplitude modulation signal, the input end of the voltage holding circuit is connected with the output end of the voltage writing circuit, the input end of the voltage compensation circuit is connected with the output end of the voltage holding circuit, the voltage compensation circuit is configured to drive a light emitting device in the light emitting circuit, the input end of the light emitting circuit is connected with the pulse width modulation signal, and the light emitting device in the light emitting circuit emits light under the driving of the voltage compensation circuit and the control of the pulse width modulation signal. The pixel driving circuit can improve the uniformity of the display brightness of the light emitting device.

Inventors

ZHANG LIANGYU
HUANG FEI
XI WENYUAN

Assignees

海信视像科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (11)

1. A display device, the display device comprising a pixel driving circuit, the pixel driving circuit comprising: The input end of the voltage writing circuit is connected with the pulse amplitude modulation signal; the input end of the voltage holding circuit is connected with the output end of the voltage writing circuit; A voltage compensation circuit having an input connected to an output of the voltage holding circuit, the voltage compensation circuit configured to drive a light emitting device in the light emitting circuit; and the input end of the light-emitting circuit is connected with a pulse width modulation signal, and a light-emitting device in the light-emitting circuit emits light under the drive of the voltage compensation circuit and the control of the pulse width modulation signal.
2. The display device according to claim 1, wherein the voltage compensation circuit includes a first driving transistor, a first switching unit, and a second switching unit; the control end of the first driving transistor is connected with the output end of the voltage holding circuit, and the input end and the output end of the first driving transistor are both connected with the light-emitting circuit; The first end of the first switch unit is connected with a reference voltage grid line, the second end of the first switch unit is connected with the control end of the first driving transistor, and the third end of the first switch unit is connected with the input end of the first driving transistor; The second switching unit is connected with the light emitting device in parallel to the output end of the first driving transistor.
3. The display device according to claim 2, wherein the first switching unit turns on the reference voltage gate line and the control terminal of the first driving transistor under the control of a first enable control signal, the reference voltage signal output from the reference voltage gate line being written into the control terminal of the first driving transistor; Under the control of a first light-emitting control signal, the first switch unit is conducted with the control end and the input end of the first driving transistor, the second switch unit is synchronously conducted, the first driving transistor utilizes the reference voltage signal to conduct threshold voltage compensation, and the light-emitting device does not emit light when the first driving transistor conducts threshold voltage compensation.
4. The display device according to claim 2, wherein the first switching unit includes a second driving transistor; the input end of the second driving transistor is connected with the reference voltage grid line, the output end of the second driving transistor is connected with the control end of the first driving transistor, and the second driving transistor is conducted under the control of a first enabling control signal.
5. The display device according to claim 2, wherein the first switching unit includes a third driving transistor, and the second switching unit includes a fourth driving transistor; the input end of the third driving transistor is connected with the control end of the first driving transistor, and the output end of the third driving transistor is connected with the input end of the first driving transistor; the fourth driving transistor and the light emitting device are connected in parallel to the output end of the first driving transistor; The third driving transistor and the fourth driving transistor are synchronously turned on under the control of the first light emitting control signal.
6. The display device according to claim 2, wherein the second input terminal of the voltage writing circuit is connected to a reference voltage gate line; The voltage writing circuit is configured to write a pulse amplitude modulation signal and a reference voltage signal to the voltage holding circuit; The voltage compensation circuit is configured to write the reference voltage signal into a control terminal of the first driving transistor, and perform threshold voltage compensation by using the reference voltage signal, wherein the voltage signal of the control terminal of the first driving transistor is changed from the reference voltage signal to a first voltage signal; The voltage holding circuit is configured to adjust a control terminal voltage signal of the first driving transistor from the first voltage signal to a second voltage signal according to a signal change between the written pulse amplitude modulation signal and a reference voltage signal; And under the condition that the voltage signal of the control end of the first driving transistor is a second voltage signal, the light emitting device emits light under the driving of the first driving transistor and the control of a pulse width modulation signal.
7. The display device according to claim 5, wherein the light-emitting circuit further comprises a fifth driving transistor; the fifth driving transistor is connected between a power supply voltage output end and an input end of the first driving transistor, the fifth driving transistor is configured to be conducted under the control of a second light-emitting control signal, and the light-emitting device emits light after the fifth driving transistor is conducted; Wherein the first light emission control signal and the second light emission control signal are opposite in level when the voltage compensation circuit performs threshold voltage compensation and the light emitting device emits light.
8. The display device according to claim 7, wherein the first light emission control signal is a high-level signal and the second light emission control signal is a low-level signal when the voltage compensation circuit performs threshold voltage compensation, and wherein the first light emission control signal is a low-level signal and the second light emission control signal is a low-level signal when the light emitting device emits light.
9. A pixel driving circuit, the pixel driving circuit comprising: the input end of the voltage writing circuit is connected with the pulse amplitude modulation signal, and the control end of the voltage writing circuit is connected with the first enabling control signal; The input end of the voltage holding circuit is connected with the output end of the voltage writing circuit, and the control end is connected with a second enabling control signal; A voltage compensation circuit having an input connected to an output of the voltage holding circuit, the voltage compensation circuit configured to drive a light emitting device in the light emitting circuit; a first control end of the voltage compensation circuit is connected with a first enabling control signal, and a second control end of the voltage compensation circuit is connected with a first light emitting control signal; the control end of the light-emitting circuit is connected with a second light-emitting control signal, the input end of the light-emitting circuit is connected with a pulse width modulation signal, and a light-emitting device in the light-emitting circuit emits light under the drive of the voltage compensation circuit and the control of the pulse width modulation signal; in the first stage, a first enabling control signal is a high-level signal, the voltage writing circuit is conducted under the action of the first enabling control signal, and the voltage compensation circuit writes reference voltage; in the second stage, the first light-emitting control signal is a high-level signal, and the voltage compensation circuit performs threshold voltage compensation by using a reference voltage under the action of the first light-emitting control signal; In the third stage, the second enabling control signal is a high-level signal, and the voltage holding circuit is conducted under the action of the second enabling control signal; in the fourth stage, the second light-emitting control signal is a high-level signal, and the light-emitting circuit is turned on under the action of the second light-emitting control signal.
10. The pixel driving circuit according to claim 9, wherein the voltage compensation circuit includes a first driving transistor, a second driving transistor, a third driving transistor, and a fourth driving transistor; the control end of the first driving transistor is connected with the output end of the voltage holding circuit, and the input end and the output end of the first driving transistor are both connected with the light-emitting circuit; The input end of the second driving transistor is connected with a reference voltage grid line, the output end of the second driving transistor is connected with the control end of the first driving transistor, and the control end of the second driving transistor is connected with a first enabling control signal; The input end of the third driving transistor is connected with the control end of the first driving transistor, the output end of the third driving transistor is connected with the input end of the first driving transistor, and the control end of the third driving transistor is connected with a first light emitting control signal; the fourth driving transistor and the light emitting device are connected in parallel to the output terminal of the first driving transistor, the control end of the fourth driving transistor is connected with a first light emitting control signal; In the first stage, the second driving transistor is conducted under the action of the first enabling control signal, and in the second stage, the third driving transistor and the fourth driving transistor are conducted under the action of the first light emitting control signal.
11. A control method of a pixel driving circuit, which is applied to the display device according to any one of claims 1 to 8, comprising the steps of: In the first stage, the voltage writing circuit writes the pulse amplitude modulation signal into the voltage holding circuit, and the voltage compensating circuit writes the reference voltage signal into the control end of the first driving transistor; In the second stage, the voltage compensation circuit performs threshold voltage compensation by using the reference voltage signal, so that the control end voltage signal of the first driving transistor is changed into a first voltage signal; The voltage holding circuit adjusts the voltage signal of the control end of the first driving transistor from the first voltage signal to a second voltage signal according to the signal change between the written pulse amplitude modulation signal and the reference voltage signal; in the fourth stage, when the voltage signal at the control end of the first driving transistor is the second voltage signal, the light emitting device in the light emitting circuit emits light under the driving of the first driving transistor and under the control of the pulse width modulation signal.

Description

Display device, pixel driving circuit, and control method of pixel driving circuit Technical Field The present application relates to the field of pixel driving technologies, and in particular, to a display device, a pixel driving circuit, and a control method of the pixel driving circuit. Background Micro LEDs (light-emitting diodes) are becoming a commonly used light-emitting device for display devices due to their self-luminous properties. Currently, the current level through Micro LEDs is controlled, usually by PAM (Pulse Amplitude Modulation ) or PWM (Pulse width modulation, pulse width modulation), so as to achieve the light emission luminance control of the Micro LEDs. However, since the light-emitting current of the Micro LED is generally small, it is difficult to control the display luminance of the Micro LED by precisely controlling the current level of the Micro LED, which results in poor uniformity of the display luminance of the Micro LED. Disclosure of Invention Based on this, it is necessary to provide a display device, a pixel driving circuit, and a control method of the pixel driving circuit that can improve uniformity of display luminance of a light emitting device. In a first aspect, a display device is provided, the display device including a pixel driving circuit, the display device including The pixel driving circuit includes: The input end of the voltage writing circuit is connected with the pulse amplitude modulation signal; the input end of the voltage holding circuit is connected with the output end of the voltage writing circuit; A voltage compensation circuit having an input connected to an output of the voltage holding circuit, the voltage compensation circuit configured to drive a light emitting device in the light emitting circuit; and the input end of the light-emitting circuit is connected with a pulse width modulation signal, and a light-emitting device in the light-emitting circuit emits light under the drive of the voltage compensation circuit and the control of the pulse width modulation signal. The application discloses a pixel driving circuit, which comprises a voltage writing circuit, a voltage holding circuit, a voltage compensating circuit and a light emitting circuit, wherein the input end of the voltage writing circuit is connected with a pulse amplitude modulation signal, the input end of the voltage holding circuit is connected with the output end of the voltage writing circuit, and the input end of the voltage compensating circuit is connected with the output end of the voltage holding circuit, so that the voltage information of the pulse amplitude modulation signal can be transmitted to the voltage compensating circuit, the voltage compensating circuit can drive a light emitting device in the light emitting circuit according to the voltage information of the pulse amplitude modulation signal, so that the light emitting device can be controlled based on the pulse amplitude modulation signal, and the light emitting device can be controlled based on the pulse width modulation signal. In one embodiment, the voltage compensation circuit further includes a first driving transistor, a first switching unit, and a second switching unit; the control end of the first driving transistor is connected with the output end of the voltage holding circuit, and the input end and the output end of the first driving transistor are both connected with the light-emitting circuit; The first end of the first switch unit is connected with a reference voltage grid line, the second end of the first switch unit is connected with the control end of the first driving transistor, and the third end of the first switch unit is connected with the input end of the first driving transistor; The second switching unit is connected with the light emitting device in parallel to the output end of the first driving transistor. The voltage compensation circuit also comprises a first driving transistor, a first switching unit and a second switching unit, wherein the control end of the first driving transistor is connected with the output end of the voltage holding circuit, the input end and the output end of the first driving transistor are both connected with the light-emitting circuit, the first end of the first switching unit is connected with the reference voltage grid line, the second end of the first switching unit is connected with the control end of the first driving transistor, and the third end of the first switching unit is connected with the input end of the first driving transistor. In one embodiment, under the control of a first enable control signal, the first switch unit turns on the reference voltage gate line and the control terminal of the first driving transistor, and the reference voltage signal output by the reference voltage gate line is written into the control terminal of the first driving transistor; Under the control of a first light-emitting control signal, the first switch un