Pixel driver circuit, pixel driving method, display panel and display device

Patent metadata

Field	Value
Publication number	US-10262594-B2
Application number	US-201615519961-A
Country	US
Kind code	B2
Filing date	Aug 29, 2016
Priority date	Jan 4, 2016
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A pixel driver circuit includes a driving transistor, a first storage capacitor, a second storage capacitor, a threshold compensation unit, a data writing and a light-emitting control unit. The threshold compensation is configured to control the driving transistor to be turned on at a threshold compensation stage and discharge toward a resetting voltage line until the driving transistor is turned off. The data writing is configured to write a data voltage into a gate electrode of the driving transistor at a data writing stage. The light-emitting control is configured to enable the driving transistor to be turned on at a light-emitting stage, so as to drive a light-emitting element to emit light.

First claim

What is claimed is:

1. A pixel driver circuit, comprising a driving transistor, a first storage capacitor, a second storage capacitor, a threshold compensation circuit, a data writing circuit and a light-emitting control circuit, wherein
a gate electrode of the driving transistor is connected to a first end of the first storage capacitor, and a first electrode of the driving transistor is connected to a second end of the first storage capacitor;
a first end of the second storage capacitor is configured to receive a first power source voltage, and a second end of the second storage capacitor is connected to the second end of the first storage capacitor;
the threshold compensation circuit is configured to, at a threshold compensation stage of each display period, control the gate electrode of the driving transistor to receive a reference voltage and enable a second electrode of the driving transistor to be connected to a resetting voltage line, so as to enable the driving transistor to be turned on and discharge toward the resetting voltage line until the driving transistor is turned off;
the data writing circuit is configured to, at a data writing stage of each display period, write a data voltage into the gate electrode of the driving transistor;
the light-emitting control circuit is configured to, at a light-emitting stage of each display period, control the first electrode of the driving transistor to receive the first power source voltage and enable the second electrode of the driving transistor to be connected to a light-emitting element, so as to enable the driving transistor to be turned on and drive the light-emitting element to emit light;
a total amount of charges stored in the first storage capacitor and a total amount of charges stored in the second storage capacitor at the threshold compensation stage is equal to those at the data writing stage;
an amount of charges stored in the first storage capacitor at the data writing stage is equal to an amount of charges stored in the first storage capacitor at a light-emitting control stage;
within each display period, the threshold compensation stage further comprises a resetting stage;
the threshold compensation circuit is further configured to, at the resetting stage, control the gate electrode of the driving transistor to receive the reference voltage and control the second electrode of the driving transistor to receive a resetting voltage;
the light-emitting control circuit is further configured to, at the resetting stage, control the first electrode of the driving transistor to receive the first power source voltage and enable the second electrode of the driving transistor to be connected to the light-emitting element;
the driving transistor is in an amplified state or a saturation state at the resetting stage;
the light-emitting element comprises an organic light-emitting diode (OLED), an anode of the OLED is connected to the second electrode of the driving transistor through the light-emitting control circuit, and a cathode of the OLED is configured to receive a second power source voltage; and
at the resetting stage, a difference between the resetting voltage from the resetting voltage line and the second power source voltage is smaller than an on-state threshold voltage of the OLED.

2. The pixel driver circuit according to claim 1 , wherein the threshold compensation circuit comprises a first compensating transistor and a second compensating transistor;
a gate electrode of the first compensating transistor is configured to receive a resetting control signal, a first electrode of the first compensating transistor is connected to the second electrode of the driving transistor, and a second electrode of the first compensating transistor is connected to the resetting voltage line; and
a gate electrode of the second compensating transistor is configured to receive the resetting control signal, a first electrode of the second compensating transistor is connected to the gate electrode of the driving transistor, and a second electrode of the second compensating transistor is configured to receive the reference voltage.

3. The pixel driver circuit according to claim 1 , wherein the threshold compensation circuit comprises a first compensating transistor and a second compensating transistor;
a gate electrode of the first compensating transistor is configured to receive a resetting control signal, a first electrode of the first compensating transistor is connected to the second electrode of the driving transistor, and a second electrode of the first compensating transistor is connected to the resetting voltage line; and
a gate electrode of the second compensating transistor is configured to receive the resetting control signal, a first electrode of the second compensating transistor is connected to the gate electrode of the driving transistor, and a second electrode of the second compensating transistor is configured to receive the reference voltage.

4. The pixel driver circuit according to claim 2 , wherein the first compensating transistor and the second compensating transistor are both P-type transistors.

5. The pixel driver circuit according to claim 1 , wherein the data writing circuit comprises a data writing transistor, a gate electrode of the data writing transistor is configured to receive a scanning signal, a first electrode of the data writing transistor is connected to the gate electrode of the driving transistor, and a second electrode of the data writing transistor is configured to receive a data voltage.

6. The pixel driver circuit according to claim 5 , wherein the data writing transistor is a P-type transistor.

7. The pixel driver circuit according to claim 3 , wherein the data writing circuit comprises a data writing transistor, a gate electrode of the data writing transistor is configured to receive a scanning signal, a first electrode of the data writing transistor is connected to the gate electrode of the driving transistor, and a second electrode of the data writing transistor is configured to receive a data voltage.

8. The pixel driver circuit according to claim 1 , wherein the light-emitting control circuit comprises a first light-emitting control transistor and a second light-emitting control transistor;
a gate electrode of the first light-emitting control transistor is configured to receive a light-emitting control signal, a first electrode of the first light-emitting control transistor is configured to receive the first power source voltage, and a second electrode of the first light-emitting control transistor is connected to the first electrode of the driving transistor; and
a gate electrode of the second light-emitting control transistor is configured to receive the light-emitting control signal, a first electrode of the second light-emitting control transistor is connected to the second electrode of the driving transistor, and a second electrode of the second light-emitting control transistor is connected to the light-emitting element.

9. The pixel driver circuit according to claim 8 , wherein the first light-emitting control transistor and the second light-emitting control transistor are both P-type transistors.

10. The pixel driver circuit according to claim 7 , wherein the light-emitting control circuit comprises a first light-emitting control transistor and a second light-emitting control transistor;
a gate electrode of the first light-emitting control transistor is configured to receive a light-emitting control signal, a first electrode of the first light-emitting control transistor is configured to receive the first power source voltage, and a second electrode of the first light-emitting control transistor is connected

Assignees

• Boe Technology Group Co Ltd

Inventors

• Ma Zhanjie

Classifications

• G09G2310/0262

  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 · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2300/0852

  being a dynamic memory with more than one capacitor · CPC title

• G09G2310/0251

  Precharge or discharge of pixel before applying new pixel voltage · CPC title

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title