Light emitting display and method of driving thereof

Abstract

There are provided a light emitting display comprising at least a light emitting unit comprising at least two light emitting diodes which are electrically connected to the same driving unit to emit light, and a plurality of voltage sources whereby one voltage source supplies a voltage different from the other voltage(s) supplied from the other voltage source(s) to each of the light emitting diodes.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a circuit diagram illustrating a related art active matrix organic light emitting display;

FIG. 2 is a circuit diagram illustrating an active matrix light emitting display according to an embodiment of the present invention;

FIG. 3 is a circuit diagram illustrating a driving unit, a light emitting unit and three voltage sources of the active matrix organic light emitting display according to another embodiment of the present invention;

FIG. 4 is a circuit diagram illustrating the active matrix light emitting display of FIG. 2;

FIG. 5 is a view illustrating subfields depending on one frame for driving the active matrix light emitting display of FIG. 4;

FIG. 6 is a waveform diagram illustrating a selection signal for driving the active matrix light emitting display of FIG. 4;

FIG. 7 is a view illustrating subfields depending on one frame for driving the active matrix light emitting display of FIG. 6;

FIG. 8 is another view illustrating subfields depending on one frame for driving the active matrix light emitting display of FIG. 4;

FIG. 9 is another waveform diagram illustrating a selection signal for driving the active matrix light emitting display of FIG. 4; and

FIG. 10 is a circuit diagram illustrating an active matrix light emitting display according to another embodiment of the present invention.

Claims

1. A light emitting display, comprising: a driving unit being electrically connected to a data line and a scan line;a light emitting unit comprising at least two light emitting diodes which are electrically connected to the same driving unit to emit a light;a plurality of voltage sources whereby one voltage source supplies a voltage different from another voltage supplied from another voltage source to a respective one of the light emitting diodes; anda selection unit between the voltage sources and the light emitting diodes and selectively connecting the light emitting diodes to the voltage sources.

2. The light emitting display of claim 1, wherein the selection unit includes at least one transistor between each of the voltage sources and one of the light emitting diodes.

3. The light emitting display of claim 1, wherein the light emitting unit comprises three light emitting diodes each of which emits one of red, green and blue light and is electrically connected to one of at least two of the voltage sources.

4. The light emitting display of claim 1, wherein the light emitting diodes are organic light emitting diodes comprising organic light emitting layers.

5. The light emitting display of claim 1, wherein a selection unit sequentially connects the light emitting diodes to the voltage sources.

6. The light emitting display of claim 3, wherein each of the three light emitting diodes is connected to a different one of the at least two voltage sources.

7. A light emitting display, comprising: a driving unit electrically connected to a data line and a scan line;a light emitting unit comprising at least two light emitting diodes electrically connected to the same driving unit to emit light;a plurality of ground sources whereby one ground source supplies a ground voltage different from another ground source supplied from another ground source to a respective one of the light emitting diodes; anda selection unit between the ground sources and the light emitting diodes and selectively connecting the light emitting diodes to the ground sources.

8. The light emitting display of claim 7, wherein the selection unit includes at least one transistor between one of the light emitting diodes and each of the ground sources.

9. The light emitting display of claim 7, wherein the light emitting unit comprises three light emitting diodes each of which emits one of red, green and blue light and is electrically connected to one of at least two of the ground sources.

10. The light emitting display of claim 7, wherein the light emitting diodes are organic light emitting diodes comprising organic light emitting layers.

11. The light emitting display of claim 7, wherein a selection unit sequentially connects the light emitting diodes to the ground sources.

12. The light emitting display of claim 9, wherein each of the three light emitting diodes is connected to a different one of the at least two ground.

13. A method of driving a light emitting display, comprising; sequentially supplying a data signal through a data line depending on a scan signal that is sequentially supplied through a scan line to a driving unit; andselectively and sequentially supplying different voltages from different voltage sources respectively to each of at least two light emitting diodes electrically connected to the same driving unit.

14. The method of claim 13, wherein the light emitting diodes comprise three light emitting diodes each of which emits one of red, green and blue light and are electrically connected to one of at least two of the different voltage sources.

15. The method of claim 13, wherein the light emitting diodes are organic light emitting diodes comprising organic light emitting layers.

16. The method of claim 14, wherein the voltages of three voltage sources supplied to three emitting diodes are different from each other.

17. The method of claim 13, further comprising: providing a selection signal for a respective color of light emitting diode substantially during a respective subfield and a part of next subfield, wherein a frame includes a subfield for each respective color of light emitting diode; andwherein the amplitude of the K-th data signal is substantially defined by the equation:

18. The method of claim 17, wherein amplitude of a last-supplied data signal is equal to the unit data signal.

19. The method of claim 13, further comprising: providing a selection signal for a respective color of light emitting diode substantially only during a respective subfield, wherein a frame includes a subfield for each respective color of light emitting diode; andwherein the scan signals are provided to a plurality of the scan lines for a respective color of light emitting diodes sequentially in a first scan direction in a first frame, and the plurality of the scan lines for the respective color in a second scan direction in a second frame, the second scan direction reverse of the first scan direction.

20. The method of claim 19, wherein the scan signals are supplied in a first direction for a first subfield and in a second direction for a second subfield subsequent to the first subfield of the same frame.

21. The method of claim 20, wherein the scan signals for a third subfield subsequent to the second subfield of the same frame are supplied in the first direction.

22. The method of claim 21, wherein one of the first and second direction is upward and the other of the first and second direction is downward.

23. The method of claim 20, wherein scan signals for a last subfield of a first frame are supplied in a first direction and scan signals for a first subfield of a second frame are supplied in a second direction, wherein the first direction is opposite the second directions.