Pixel and organic light emitting display device using the same

Patent metadata

Field	Value
Publication number	US-9196196-B2
Application number	US-87315310-A
Country	US
Kind code	B2
Filing date	Aug 31, 2010
Priority date	Feb 9, 2010
Publication date	Nov 24, 2015
Grant date	Nov 24, 2015

Abstract

There is provided an organic light emitting display device for providing a compensation period of a threshold voltage. The organic light emitting display device includes: a scan driver configured to supply a plurality of scan signals to a plurality of scan lines, each of the scan signals having a width greater than two horizontal periods; a data driver configured to supply a plurality of data signals to a plurality of data lines; and a pixel including an organic light emitting diode, a pixel circuit having a first transistor for controlling an amount of current supplied to the organic light emitting diode, and a compensation circuit configured to control a voltage of a gate electrode of the first transistor to compensate for deterioration of the organic light emitting diode; wherein the scan driver is configured to supply a current scan signal which partially overlaps in time with a previous scan signal.

First claim

What is claimed is:

1. An organic light emitting display device comprising:
a scan driver configured to sequentially supply a plurality of scan signals to a plurality of scan lines, each of the scan signals having a width greater than two horizontal periods;
a data driver configured to supply a plurality of data signals to a plurality of data lines; and
a pixel comprising an organic light emitting diode, a pixel circuit comprising a first transistor configured to control an amount of current supplied to the organic light emitting diode, and a compensation circuit comprising a first compensation transistor and a second compensation transistor and configured to control a voltage of a gate electrode of the first transistor to compensate for deterioration of the organic light emitting diode,
wherein the scan driver is configured to supply a current scan signal of the scan signals, which partially overlaps in time with a previous scan signal of the scan signals, and
wherein a gate of the first compensation transistor is controlled by the previous scan signal, and
wherein the second compensation transistor is controlled by a subsequent scan signal.

2. The organic light emitting display device as claimed in claim 1 , wherein the scan driver supplies each of the scan signals for a period having a time length of three horizontal periods.

3. The organic light emitting display device as claimed in claim 2 , wherein the current scan signal overlaps with the previous scan signal for a period having a time length of one horizontal period.

4. The organic light emitting display device as claimed in claim 2 , wherein the scan driver is configured to sequentially supply a plurality of light emission control signals to a plurality of light emission control lines extending in a direction parallel to the scan lines, and to supply an ith light emission control signal of the light emission control signals to an ith light emission control line of the light emission control lines such that the ith light emission control signal overlaps in time with scan signals supplied to an (i−2)th scan line to an (i+3)th scan line, from among the scan signals, wherein i is an integer greater than 2.

5. An organic light emitting display device comprising:
a scan driver configured to sequentially supply a plurality of scan signals to a plurality of scan lines, each of the scan signals having a width greater than two horizontal periods;
a data driver configured to supply a plurality of data signals to a plurality of data lines; and
a pixel comprising an organic light emitting diode, a pixel circuit comprising a first transistor configured to control an amount of current supplied to the organic light emitting diode, and a compensation circuit configured to control a voltage of a gate electrode of the first transistor to compensate for deterioration of the organic light emitting diode,
wherein the scan driver is configured to supply a current scan signal of the scan signals, which partially overlaps in time with a previous scan signal of the scan signals,
wherein the scan driver is configured to sequentially supply a plurality of light emission control signals to a plurality of light emission control lines extending in a direction parallel to the scan lines, and to supply an ith light emission control signal of the light emission control signals to an ith light emission control line of the light emission control lines such that the ith light emission control signal overlaps in time with scan signals supplied to an (i−2)th scan line to an (i+3)th scan line, from among the scan signals, wherein i is an integer greater than 2, and
wherein the pixel circuit comprises:
a second transistor coupled between a first node at a gate electrode of the first transistor and a first electrode of the first transistor and configured to be turned on when the scan signal is supplied to the ith scan line;
a third transistor coupled to a data line of the data lines and a second node and configured to be turned on when a corresponding one of the scan signals is supplied to the (i+3)th scan line;
a first capacitor coupled to the first node and the second node;
a fourth transistor coupled to the second node and a reference power source and configured to be turned on when a corresponding one of the scan signals is supplied to the ith scan line;
a fifth transistor coupled between the first electrode of the first transistor and the first power source and turned off when a corresponding one of the light emission control signals is supplied to the ith light emission control line;
a sixth transistor coupled between the first node and the first power source and configured to be turned on when the scan signal is supplied to the (i−2)th scan line; and
a second capacitor for storing a voltage corresponding to the data signal supplied for a period during which the third transistor is turned on.

6. The organic light emitting display device as claimed in claim 5 , wherein the second capacitor is coupled between an anode electrode of the organic light emitting diode and the first node.

7. The organic light emitting display device as claimed in claim 5 , wherein the second capacitor is coupled between an anode electrode of the organic light emitting diode and the second node.

8. The organic light emitting display device as claimed in claim 5 , wherein the reference power source has a voltage higher than a voltage of a data signal corresponding to a black gray level from among the data signals and lower than a voltage of a data signal corresponding to a white gray level from among the data signals.

9. The organic light emitting display device as claimed in claim 5 , wherein a seventh transistor is coupled between a control power source and a fourth node, and wherein the compensation circuit further comprises:
an eighth transistor coupled between the fourth node and an anode electrode of the organic light emitting diode; and
a third capacitor for controlling a voltage of a gate electrode of the first transistor in response to a voltage change of the fourth node as a common node of the seventh transistor and the eighth transistor,
wherein the scan driver is configured to control the seventh and eighth transistors such that at most one of the seventh and eighth transistors is turned on at any time.

10. The organic light emitting display device as claimed in claim 9 , wherein the third capacitor is coupled between the fourth node and the first node.

11. The organic light emitting display device as claimed in claim 9 , wherein the third capacitor is coupled between the fourth node and the second node.

12. The organic light emitting display device as claimed in claim 9 , wherein a voltage of the control power source is substantially equal to that of the reference power source.

13. The organic light emitting display device as claimed in claim 9 , wherein the control power source has a voltage lower than a threshold voltage of the organic light emitting diode.

14. The organic light emitting display device as claimed in claim 9 , wherein the control power source has a voltage higher than a threshold voltage of the organic light emitting diode.

15. The organic light emitting display device as claimed in claim 9 , wherein the seventh transistor is configured to be turned on when the scan signal is supplied to the (i−2)th scan line and the eighth transistor is configured to be turned on when the scan signal is supplied to the (i+3)th scan line.

16. The organic light emitting display device as claimed in claim 1 , wherein the data driver is configured to supply the data signal

Assignees

• Chung Bo-Yong
• Park Yong-Sung
• Samsung Display Co Ltd

Inventors

• Chung Bo-Yong
• Park Yong-Sung

Classifications

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G2300/0861

  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 title

• H05B45/44

  with an active control inside an LED matrix · CPC title

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• H05B45/60

  Circuit arrangements for operating LEDs comprising organic material, e.g. for operating organic light-emitting diodes [OLED] or polymer light-emitting diodes [PLED] · CPC title