Organic light emitting display panel and pixel compensation method
An organic light emitting display panel and a pixel compensation method are provided. The organic light emitting display panel includes: a pixel array including pixel regions divided into M rows and N columns; a plurality of pixel driving circuits, each includes a light emitting diode and a driving transistor for driving the light emitting diode, and the light emitting diodes are located in the pixel regions; and a plurality of pixel compensation circuits configured to sample an anode voltage of the light emitting diode are in at least one of the pixel driving circuits. A light emitting current flows through the light emitting diode, and generates a compensation signal based on the anode voltage and the light emitting current.
1. An organic light emitting display panel, comprising:
a pixel array comprising pixel regions divided into M rows and N columns;
a plurality of pixel driving circuits, each including a light emitting diode, a driving transistor for driving the light emitting diode, wherein each of the light emitting diodes is located in one of the pixel regions; and
a plurality of pixel compensation circuits each associated with one of the pixel driving circuits, configured to sample an anode voltage of the light emitting diode in one associated pixel driving circuits and a light emitting current flowing through the light emitting diode, and generate a compensation signal based on the anode voltage and the light emitting current,
wherein the pixel compensation circuit comprises a first voltage sampling unit, a second voltage sampling unit and a calculation unit,
wherein the first voltage sampling unit comprises a sampling resistor and a first differential amplifier, wherein the sampling resistor is arranged on a current path of the light emitting current, wherein two input terminals of the first differential amplifier are electrically connected to two ends of the sampling resistor respectively, and wherein the light emitting current is determined based on a voltage difference between the two ends of the sampling resistor,
wherein the second voltage sampling unit is configured to sample the anode voltage of the light emitting diode,
wherein the calculation unit is configured to determine the compensation signal based on the anode voltage and the light emitting current;
wherein the second voltage sampling unit comprises a first switching transistor and a second differential amplifier;
wherein a gate of the first switching transistor is electrically connected to a first control signal terminal, wherein a first electrode of the first switching transistor is electrically connected to an anode of the light emitting diode; wherein a second electrode of the first switching transistor is electrically connected to an output terminal of the second differential amplifier;
wherein the pixel compensation circuit further comprises a first compensation capacitor; and
wherein an end of the first compensation capacitor is grounded and the second end of the first compensation capacitor is electrically connected to the first electrode of the first switching transistor.
2. The organic light emitting display panel according to claim 1 ,
wherein the pixel driving circuit further comprises a first transistor, a second transistor and a first capacitor;
wherein a gate of the first transistor is electrically connected to a second control signal terminal, wherein a first electrode of the first transistor is electrically connected to a data voltage signal line, and wherein a second electrode of the first transistor is electrically connected to the gate of the driving transistor;
wherein a first electrode of the driving transistor is electrically connected to a first voltage signal terminal, and a second electrode of the driving transistor is electrically connected to the anode of the light emitting diode and a first electrode of the second transistor;
wherein a gate of the second transistor is electrically connected to the second control signal terminal, and a second electrode of the second transistor is electrically connected to the first electrode of the first switching transistor; and
wherein a cathode of the light emitting diode is electrically connected to a second voltage signal terminal.
3. The organic light emitting display panel according to claim 1 , wherein the sampling resistor is arranged between the first voltage signal terminal and the first electrode of the driving transistor.
4. The organic light emitting display panel according to claim 3 ,
wherein the pixel compensation circuit further comprises a second switching transistor,
wherein a gate of the second switching transistor is electrically connected to a third control signal terminal, wherein a first electrode of the second switching transistor is electrically connected to a reference voltage signal line, and wherein a second electrode of the second switching transistor is electrically connected to the first electrode of the first switching transistor.
5. The organic light emitting display panel according to claim 4 ,
Wherein the sampling resistor is arranged on a reference voltage signal line;
wherein the pixel compensation circuit further comprises a third switching transistor,
wherein a gate of the third switching transistor is electrically connected to a third control signal terminal, a first electrode of the third switching transistor is electrically connected to an end of the sampling resistor, and a second electrode of the third switching transistor is electrically connected the first electrode of the first switching transistor.
6. The organic light emitting display panel according to claim 1 , wherein
the pixel driving circuit further includes a first transistor, a second transistor and a first capacitor;
a gate of the first transistor is electrically connected to a second control signal terminal, a first electrode of the first transistor is electrically connected to a data voltage signal line, and a second electrode of the first transistor is electrically connected to the gate of the driving transistor;
a first electrode of the driving transistor is electrically connected to a first voltage signal terminal, and a second electrode of the driving transistor is electrically connected to the anode of the light emitting diode and a first electrode of the second transistor;
a gate of the second transistor is electrically connected to a fourth control signal terminal, and a second electrode of the second transistor is electrically connected to the first electrode of the first switching transistor; and
a cathode of the light emitting diode is electrically connected to a second voltage signal terminal.
7. The organic light emitting display panel according to claim 1 , wherein the pixel compensation circuits each is configured to sample the anode voltage and the light emitting current flowing through the light emitting diode, in the associated pixel region of the same column.
8. A pixel compensation method applied to the organic light emitting display panel according to claim 1 , comprising:
providing a reset signal to the anode of the light emitting diode and providing an initial data signal to the gate of the driving transistor;
providing, by the driving transistor, the light emitting current to the light emitting diode;
sampling the light emitting current and the anode voltage of the light emitting diode; and
determining a compensation signal based on the light emitting current, the anode voltage of the light emitting diode and the initial data signal.
9. The pixel compensation method according to claim 8 , further comprising:
providing a data voltage signal to the gate of the driving transistor to cause the light emitting diode to emit light, wherein the data voltage signal is a voltage signal compensated by the compensation signal.