Organic light emitting display device and method of driving the same

• US 9,728,123 B2
• Filed: 01/27/2014
• Issued: 08/08/2017
• Est. Priority Date: 07/08/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Park, Won-Sang, Kim, Il-Nam
• Primary Examiner(s): Yodichkas, Aneeta
• Application Number:
  US14/165,369
• Publication Number:
  US 20150009194A1
• Time in Patent Office: 1,289 Days
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• 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 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

An organic light emitting display device includes a plurality of pixels, each including a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixel; and an initialization power source configured to supply a plurality of initialization voltages to the pixels, wherein the first and second blue sub-pixels are adjacent to each other and are coupled to a same data line.

Claims

1. An organic light emitting display device comprising:

a plurality of pixels, each comprising a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixel; and

an initialization power source configured to supply a first initialization voltage to the red sub-pixel and to the green sub-pixel, to supply a second initialization voltage to the first blue sub-pixel, and to supply a third initialization voltage to the second blue sub-pixel,

wherein the first and second blue sub-pixels are adjacent to each other and are coupled to a same data line.

2. The organic light emitting display device of claim 1, wherein each of the red sub-pixel, the green sub-pixel, the first blue sub-pixel and the second blue sub-pixel comprises a driving transistor comprising a gate electrode configured to receive any one of the plurality of initialization voltages before a data signal is supplied.

3. The organic light emitting display device of claim 2, wherein the first initialization voltage is a voltage that is lower than the data signal.

4. The organic light emitting display device of claim 2, wherein the initialization power source is configured to supply a low second initialization voltage that is lower than the data signal, or a high second initialization voltage that is higher than the data signal.

5. The organic light emitting display device of claim 2, wherein the initialization power source is configured to supply a low third initialization voltage that is lower than the data signal, or a high third initialization voltage that is higher than the data signal.

6. The organic light emitting display device of claim 1, wherein the first blue sub-pixel comprises an organic light emitting diode formed of a sky blue organic light emitting material.

7. The organic light emitting display device of claim 1, wherein the second blue sub-pixel comprises an organic light emitting diode formed of a deep blue organic light emitting material.

8. The organic light emitting display device of claim 1, further comprising:

a scan driver configured to supply a scan signal to a plurality of scan lines coupled to the pixels at respective horizontal lines and supply an emission control signal to a plurality of emission control lines; and

a data driver configured to supply a data signal to a plurality of data lines coupled to the pixels at respective vertical lines.

9. The organic light emitting display device of claim 8, wherein each of the red sub-pixel, the green sub-pixel, the first blue sub-pixel and the second blue sub-pixel comprises:

an organic light emitting diode configured to generate light of a corresponding one of red, green and blue; and

a pixel circuit configured to control an amount of current supplied to the organic light emitting diode.

10. The organic light emitting display device of claim 9, wherein each pixel circuit comprises:

a driving transistor configured to control an amount of current flowing through the organic light emitting diode from a first power source coupled to the driving transistor via a first node;

a second transistor coupled between a gate electrode of the driving transistor and the initialization power source, the second transistor being configured to turn on when the scan signal is supplied to a previous scan line of the plurality of scan lines;

a third transistor coupled between the gate electrode and a second electrode of the driving transistor, the third transistor being configured to turn on when the scan signal is supplied to a current scan line of the plurality of scan lines; and

a fourth transistor coupled between the first node and a data line of the plurality of data lines, the fourth transistor being configured to turn on when the scan signal is supplied to the current scan line.

11. The organic light emitting display device of claim 10, wherein each pixel circuit further comprises:

a fifth transistor coupled between the first node and the first power source, the fifth transistor being configured to turn off when the emission control signal is supplied to a current emission control line of the plurality of emission control lines; and

a sixth transistor coupled between the second electrode of the driving transistor and the organic light emitting diode, the sixth transistor being configured to turn off when the emission control signal is supplied to the current emission control line.

12. The organic light emitting display device of claim 11, wherein the emission control signal supplied to the current emission control line overlaps with the scan signal supplied to the previous scan line and the current scan line.

13. A method of driving an organic light emitting display device which comprises a pixel comprising a red sub-pixel, a green sub-pixel, a first blue sub-pixel and a second blue sub-pixel, the method comprising:

controlling whether or not the first and second blue sub-pixels sharing a data line emit light;

supplying a data signal to the red sub-pixel, the green sub-pixel, the first blue sub-pixel and the second blue sub-pixel;

allowing the sub-pixel set in an emission state, by including the red and green sub-pixels, to emit light, corresponding to the data signal; and

supplying a first initialization voltage to the red and green sub-pixels, a second initialization voltage to the first blue sub-pixel, and a third initialization voltage to the second blue sub-pixel.

14. The method of claim 13, wherein the first blue sub-pixel comprises an organic light emitting diode formed of a sky blue organic light emitting material.

15. The method of claim 13, wherein the second blue sub-pixel comprises an organic light emitting diode formed of a deep blue organic light emitting material.

16. The method of claim 13, wherein each of the red sub-pixel, the green sub-pixel, the first blue sub-pixel and the second blue sub-pixel comprises a driving transistor diode-coupled during a period in which the data signal is supplied.

17. The method of claim 16, wherein the controlling comprises:

supplying, to a gate electrode of the driving transistor of the first blue sub-pixel, a high second initialization voltage higher than the data signal or a low second initialization voltage lower than the data signal, before the data signal is supplied; and

supplying, to a gate electrode of the driving transistor of the second blue sub-pixel, a high third initialization voltage higher than the data signal or a low third initialization voltage lower than the data signal, before the data signal is supplied.