Display device and driving method thereof

Patent metadata

Field	Value
Publication number	US-9576536-B2
Application number	US-201414218956-A
Country	US
Kind code	B2
Filing date	Mar 18, 2014
Priority date	Oct 10, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

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.

First claim

What is claimed is:

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,
wherein the sensor comprises:
an amplifier configured to generate an output voltage according to a voltage difference input to a plurality of input terminals;
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;
a current sensor coupled to the first node and configured to detect the sensing current;
a second transistor comprising a first terminal coupled to the current sensor, and a second terminal coupled to the first node; and
a switching element coupled to the first node and configured to be turned off in order to detect the sensing current according to the test signal.

2. The display device of claim 1 , 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.

3. 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.

4. The display device of claim 3 , wherein the 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.

5. The display device of claim 1 , wherein the current sensor comprises a current mirror.

6. The display device of claim 1 , wherein the current sensor comprises a sensing resistor, and is configured to detect a voltage of the sensing resistor according to the sensing current.

7. The display device of claim 1 , 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.

8. 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.

9. 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,
wherein a switching element of a sensor is turned off in order to detect the sensing current according to the test signal, and
wherein the sensor comprises:
the switching element;
an amplifier configured to generate an output voltage according to a voltage difference input to a plurality of input terminals;
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;
a current sensor coupled to the first node and configured to detect the sensing current; and
a second transistor comprising a first terminal coupled to the current sensor, and a second terminal coupled to the first node.

10. The method of claim 9 , 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.

11. The method of claim 10 , wherein the detecting the sensing current comprises stopping a driving of the 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.

12. The method of claim 9 , 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.

13. The method of claim 9 , 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.

14. The method of claim 9 , 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.

15. The method of claim 9 , further comprising compensating the data signal as a compensation value corresponding to a value of the sensing current.

Assignees

• Samsung Display Co Ltd
• Korea Advanced Inst Sci & Tech

Inventors

• Kwon Oh Jo
• Min Kyung Youl
• Shin Choong Sun
• Ahn Hee Sun
• Kim Hyun Sik
• Bang Jun Suk
• Cho Gyu Hyeong

Classifications

• G09G2320/0295

  by monitoring each display pixel · CPC title

• G09G2300/0819

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

• G09G2300/0814

  used for selection purposes, e.g. logical AND for partial update · CPC title

• G09G3/3291 Primary

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements · CPC title

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title