DISPLAY DEVICE AND DRIVING METHOD THEREOF

• US 20150103062A1
• Filed: 03/18/2014
• Published: 04/16/2015
• Est. Priority Date: 10/10/2013
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology, Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Korea Advanced Institute of Science and Technology, Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kwon, Oh Jo, Min, Kyung Youl, Shin, Choong Sun, Ahn, Hee Sun, Kim, Hyun Sik, Bang, Jun Suk, Cho, Gyu Hyeong
• Granted Patent: US 9,576,536 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• 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

Abstract

A display device according to an embodiment of the present invention includes: a pixel configured to emit light according to a data signal supplied to a data line, a power source voltage supplier configured to supply a power source voltage to the pixel, a driving transistor configured to drive the pixel to be emitted according to the data signal and the power source voltage, and a sensor configured to supply a test signal to a data line and to detect a sensing current flowing to the data line through the driving transistor according to the test signal.

Claims

1. A display device comprising:

a pixel configured to emit light according to a data signal supplied to a data line;

a power source voltage supplier configured to supply a power source voltage to the pixel;

a driving transistor configured to drive the pixel according to the data signal and the power source voltage; and

a sensor configured to supply a test signal to the data line and to detect a sensing current flowing to the data line through the driving transistor according to the test signal.

2. The display device of claim 1, wherein the sensor comprises:

an amplifier configured to generate an output voltage according to a voltage difference input to a plurality of input terminals;

an output terminal coupled to the amplifier and configured to supply the test signal to the data line through a plurality of transistors configured to be driven according to the output voltage;

a current sensor coupled to the output terminal and configured to detect the sensing current; and

a switching element coupled to the output terminal and configured to drive the sensing current.

3. The display device of claim 2, wherein the plurality of transistors comprise:

a first transistor comprising a first terminal coupled to a voltage source, and a second terminal coupled to the data line and to the input terminal of the amplifier at a first node; and

a second transistor comprising a first terminal coupled to the current sensor, and a second terminal coupled to the first node.

4. The display device of claim 3, wherein the first transistor is configured to operate according to the output voltage and is configured to supply a current supplied from the voltage source to the first node.

5. The display device of claim 1, further comprising:

a first switching transistor comprising a first terminal coupled to the data line, and a second terminal coupled to a gate of the driving transistor and configured to operate according to a scanning signal supplied to a scan line; and

a second switching transistor comprising a first terminal coupled to the driving transistor, and a second terminal coupled to the first switching transistor at a second node and configured to operate according to the scanning signal.

6. The display device of claim 5, wherein a switching element, which is configured to drive the sensing current, is configured to be turned off when a voltage of the second node is substantially equivalent to a voltage of the test signal.

7. The display device of claim 2, wherein the current sensor comprises a current mirror.

8. The display device of claim 2, wherein the current sensor comprises a sensing resistor, and is configured to detect a voltage of the sensing resistor according to the sensing current.

9. The display device of claim 2, wherein the current sensor comprises a sensing capacitor, and is configured to detect a charged voltage of the sensing capacitor corresponding to the sensing current.

10. The display device of claim 1, further comprising a data compensator configured to compensate the data signal as a compensation value corresponding to a value of the sensing current.

11. A method for driving a display device comprising a pixel configured to emit a light according to a data signal supplied to a data line, a power source voltage supplier configured to supply a power source voltage to the pixel, and a driving transistor configured to drive the pixel according to the power source voltage, the method comprising:

supplying a test signal to the driving transistor through the data line; and

detecting a sensing current flowing to the data line according to the test signal through the driving transistor.

12. The method of claim 11, wherein the supplying the test signal comprises:

applying voltages to a plurality of input terminals of an amplifier;

supplying an output voltage, which is generated in the amplifier according to a difference of the voltages applied to the plurality of input terminals, to a gate of a plurality of transistors; and

applying the test signal to the data line from a voltage source coupled to at least one terminal of one of the plurality of transistors according to the output voltage supplied to the gate.

13. The method of claim 12, wherein the plurality of transistors comprise:

a first transistor comprising a first terminal coupled to the voltage source, and a second terminal coupled to the data line and to at least one of the input terminals of the amplifier at a first node; and

a second transistor comprising a first terminal coupled to a current sensor and a second terminal coupled to the first node.

14. The method of claim 13, wherein the supply of the test signal further comprises:

supplying a scanning signal to a scan line coupled to a gate of a first switching transistor comprising a first terminal coupled to the data line, and a second terminal coupled to a gate of the driving transistor, and supplying the scanning signal to the scan line coupled to a gate of a second switching transistor comprising a first terminal coupled to the driving transistor, and a second terminal coupled to the first switching transistor at a second node.

15. The method of claim 14, wherein the detecting the sensing current comprises stopping a driving of a switching element coupled to the first terminal of the second transistor to supply the sensing current to the current sensor when a voltage of the second node is substantially equivalent to a voltage of the test signal.

16. The method of claim 13, wherein the current sensor comprises a current mirror, and

wherein a current output from the current mirror is detected in the detecting of the sensing current.

17. The method of claim 13, wherein the current sensor comprises a sensing resistor, and

wherein a voltage value of the sensing resistor corresponding to the sensing current is detected in the detecting of the sensing current.

18. The method of claim 13, wherein the current sensor comprises a sensing capacitor, and

wherein a charged voltage value of the sensing capacitor corresponding to the sensing current is detected in the detecting of the sensing current.

19. The method of claim 11, further comprising compensating the data signal as a compensation value corresponding to a value of the sensing current.