Display device and driving method thereof

• US 20110279436A1
• Filed: 01/10/2011
• Published: 11/17/2011
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Chung, Ho-Ryun, Hyun, Chang-Ho, Komiya, Naoaki, Choi, In-Ho, Lee, Wang-Jo, Kim, Woung, Oh, Choon-Yul, Yoo, Myoung-Hwan, Jeong, Joo-Hyeon
• Granted Patent: US 8,508,525 B2
• Time in Patent Office: Days
• US Class Current: 345/212
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3283 in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements

Abstract

An organic light emitting diode (OLED) display includes a display unit including a plurality of pixels, a plurality of scan lines, and a plurality of data lines, a data driver transmitting a plurality of data signals to the plurality of data lines, a scan driver transmitting a plurality of scan signals to the plurality of scan lines, a compensation controller supplying a predetermined first current to each organic light emitting diode in each of the plurality of pixels during a sensing period for measuring a driving voltage of the organic light emitting diode for each of a plurality of pixels, receiving the driving voltage of the organic light emitting diode supplied with the first current, and outputting measuring data for the transmitted driving voltage; and a signal controller compensating an input video signal according to the measuring data to generate image data. The compensation controller is separate from and external to the data driver.

Claims

1. A display device, comprising:

a display unit including a plurality of pixels, a plurality of scan lines, and a plurality of data lines;

a data driver transmitting a plurality of data signals to the plurality of data lines;

a scan driver transmitting a plurality of scan signals to the plurality of scan lines;

a compensation controller supplying a predetermined test current to each organic light emitting diode in each of the plurality of pixels during a sensing period for measuring a driving voltage of the organic light emitting diode for each of the plurality of pixels, receiving the driving voltage of the organic light emitting diode supplied with the first current, and outputting measuring data for the transmitted driving voltage; and

a signal controller compensating an input video signal according to the measuring data to generate image data,

wherein the compensation controller is separate from and external to the data driver.

2. The display device as claimed in claim 1, wherein the compensation controller is connected to one data line of the plurality of data lines during the sensing period, and detects the driving voltage of at least one organic light emitting diode among the plurality of organic light emitting diodes connected to one data line.

3. The display device as claimed in claim 2, further comprising a selection unit including:

a plurality of compensating switches including a first terminal connected to the corresponding data line of the plurality of data lines and a second terminal connected to the compensation controller;

a plurality of data transmitting switches including a first terminal connected to the corresponding data line of the plurality of data lines and a second terminal connected to the data driver; and

a selection driver turning on the plurality of compensating switches during the sensing period, and turning on the plurality of data transmitting switches during the image display period in which the plurality of data lines are transmitted with the plurality of data signals.

4. The display device as claimed in claim 3, further comprising:

a plurality of sensing driving lines; and

a sensing driver respectively transmitting a plurality of detection signals to the corresponding sensing driving line according to the sensing control signal,

wherein the driving voltage of the organic light emitting diode (OLED) of each of the plurality of pixels is transmitted to the compensation controller during the sensing period of the plurality of detection signals.

5. The display device as claimed in claim 4, wherein the plurality of detection signals respectively have a pulse of a first level during the sensing period, and the plurality of first switches are turned on during a period in which the detection signal has the pulse of the first level.

6. The display device as claimed in claim 5, wherein the compensation controller includes:

a current source supplying the test current to the plurality of data lines during the sensing period; and

a converter digitally-converting the driving voltage of the organic light emitting diode (OLED) transmitted through the plurality of data lines during the sensing period to output the measuring data.

7. A display device, comprising:

a display unit including a plurality of pixels, a plurality of scan lines, and a plurality of data lines;

a first data driver transmitting a plurality of corresponding data signals to the plurality of first data lines of the plurality of data lines;

a second data driver transmitting a plurality of corresponding data signals to the plurality of second data lines of the plurality of data lines except for the plurality of first data lines;

a scan driver transmitting a plurality of scan signals to the plurality of scan lines;

a compensation controller supplying a predetermined test current to each organic light emitting diode in each of the plurality of pixels during a sensing period for measuring a driving voltage of the organic light emitting diode for each of the plurality of pixels, receiving the driving voltage of the organic light emitting diode supplied with the first current, and outputting measuring data for the transmitted driving voltage;

a first selection unit connecting the plurality of first data lines to the compensation controller during a first sensing period of the sensing period;

a second selection unit connecting the plurality of second data lines to the compensation controller during a second sensing period of the sensing period; and

a signal controller compensating an input video signal according to the measuring data to generate image data,

wherein the compensation controller is separate from and external to both the first and second data drivers.

8. The display device as claimed in claim 7, further comprising:

a plurality of sensing driving lines; and

a sensing driver transmitting a plurality of detection signals corresponding to the plurality of sensing driving lines during the sensing period.

9. The display device as claimed in claim 8, wherein the first selection unit includes:

a plurality of first compensating switches including a first terminal connected to the first data lines and a second terminal connected to the compensation controller; and

a plurality of first data transmitting switches including a first terminal connected to the first data lines and a second terminal receiving the corresponding data signal from the data driver.

10. The display device as claimed in claim 9, wherein the first selection unit turns on the plurality of first compensating switches during the first sensing period.

11. The display device as claimed in claim 9, wherein:

the sensing driver transmits a detection signal having a first level to measure the driving voltage of the organic light emitting diode corresponding to one sensing driving line of the plurality of sensing driving lines during the sensing period;

the period in which the corresponding detection signal is at the first level includes the first sensing period and the second sensing period; and

the first selection unit turns on the plurality of first compensating switches during the first sensing period.

12. The display device as claimed in claim 9, wherein:

the sensing driver transmits a plurality of detection signals at a first level to measure the driving voltage of the organic light emitting diode corresponding to the plurality of sensing driving lines during the first sensing period;

the sensing driver transmits a plurality of detection signals at the first level to measure the driving voltage of the organic light emitting diode corresponding to the plurality of sensing driving lines during the second sensing period; and

the first selection unit turns on the plurality of first compensating switches at least two times during the first sensing period.

13. The display device as claimed in claim 8, wherein the second selection unit includes:

a plurality of second compensating switches including a first terminal connected to the second data lines and a second terminal connected to the compensation controller; and

a plurality of second data transmitting switches including a first terminal connected to the second data lines and a second terminal receiving the corresponding data signal from the data driver.

14. The display device as claimed in claim 13, wherein the second selection unit turns on the plurality of second compensating switches during the second sensing period.

15. The display device as claimed in claim 13, wherein:

the sensing driver transmits a detection signal at a first level to measure the driving voltage of the organic light emitting diode corresponding to one sensing driving line of the plurality of sensing driving lines during the sensing period;

the period in which the corresponding detection signal is at the first level includes the first sensing period and the second sensing period; and

the second selection unit turns on the plurality of second compensating switches during the second sensing period.

16. The display device as claimed in claim 13, wherein:

the sensing driver transmits a plurality of detection signals at the first level to measure the driving voltage of the organic light emitting diode corresponding to the plurality of sensing driving lines during the first sensing period;

the sensing driver transmits a plurality of detection signals at the first level to measure the driving voltage of the organic light emitting diode corresponding to the plurality of sensing driving lines during the second sensing period; and

the second selection unit turns on the plurality of second compensating switches at least two times during the second sensing period.

17. The display device as claimed in claim 8, wherein:

the plurality of scan lines extend parallel to each other in a first direction, the plurality of data lines extend parallel to each other in a second direction intersecting the first direction, and

the plurality of sensing driving lines are parallel to the corresponding scan lines of the plurality of scan lines.

18. A method of driving a display device including a display panel having a plurality of scan lines, a plurality of data lines, a plurality of organic light emitting diodes (OLED) corresponding to the data lines and scan lines, and a converter, and displaying images according to an input video signal, comprising:

transmitting a predetermined test current to an organic light emitting diode corresponding to one data line through one data line of the plurality of data lines;

transmitting a driving voltage of the corresponding organic light emitting diode generated when a test current flows in the corresponding organic light emitting diode to the converter; and

repeating transmitting of the test current to the corresponding organic light emitting diode and transmitting of the driving voltage of the corresponding organic light emitting diode to the converter for the plurality of other data lines of the plurality of data lines.

19. The method as claimed in claim 18, further comprising:

transmitting a test current to the plurality of data lines corresponding to the plurality of organic light emitting diodes arranged in a direction in which a plurality of scan lines are formed; and

receiving each driving voltage of the plurality of organic light emitting diodes through the plurality of data lines.

20. The method as claimed in claim 18, further comprising:

receiving each driving voltage of the plurality of organic light emitting diodes;

compensating the input video signal using each driving voltage of the plurality of organic light emitting diodes; and

generating image data corresponding to the plurality of organic light emitting diodes using compensated input video signal.