Organic light emitting display and image compensating method thereof

1. An organic light emitting display device comprising:

a plurality of pixels, each of the pixels comprising:

an organic light emitting diode; and

a pixel circuit comprising a driving transistor for driving the organic light emitting diode and a switching transistor for switching a current flowing through the driving transistor in response to a sensing signal; and

a sensing circuit for sensing the current, converting the current into sensing data, and performing mura correction and image compensation for image sticking based on the sensing data and a lookup table, wherein the lookup table is generated by comparing the sensing data with previously sensed sensing data,

wherein the sensing circuit comprises:

an analog-digital converting circuit for converting the current into the sensing data;

a mura correction circuit for comparing the sensing data with original data provided from the pixel circuit to generate mura correction data; and

an image compensating circuit for generating image compensation data to compensate for image sticking in accordance with the mura correction data and the lookup table

wherein the sensing circuit further comprises a current source configured to provide a constant current at a front end of the analog-digital converting circuit.

2. The organic light emitting display device of claim 1 , wherein the sensing circuit is separated from the pixels.

3. The organic light emitting display device of claim 1 , wherein the pixel circuit is configured to apply a voltage to a cathode electrode of the organic light emitting diode such that the organic light emitting diode is reverse-biased when the sensing signal is applied to turn on the switching transistor.

4. An organic light emitting display device comprising:

a plurality of pixels, each of the pixels comprising:

an organic light emitting diode;

a pixel circuit comprising a driving transistor for driving the organic light emitting diode, and a switching transistor for switching a current flowing through the driving transistor in response to a sensing signal;

a current source for providing a current for adjusting a gate-source voltage of the driving transistor;

an analog-digital converting circuit for converting the current into sensing data;

a mura correction circuit for comparing the sensing data with original data provided from the pixel circuit to generate mura correction data; and

an image compensating circuit for generating image compensation data to compensate for image sticking in accordance with the mura correction data and a lookup table, wherein the lookup table is generated by comparing the sensing data with previously sensed sensing data;

wherein the current source is configured to provide a constant current at a front end of the analog-digital converting circuit.

5. A method of compensating for an image displayed by an organic light emitting display device comprising an organic light emitting diode and a pixel circuit comprising a driving transistor for driving the organic light emitting diode, the method comprising:

providing a constant current for adjusting a gate-source voltage of the driving transistor;

sensing a current supplied by the driving transistor and converting the current into sensing data;

comparing the sensing data with original data to generate mura correction data; and

generating image compensation data to compensate for image sticking of the organic light emitting display device in accordance with the mura correction data and a lookup table that is generated by comparing the sensing data with previously sensed sensing data.

6. The method of claim 5 , further comprising reverse-biasing the organic light emitting diode by applying a voltage to a cathode electrode of the organic light emitting diode.

7. The method of claim 6 , further comprising sensing the current supplied by the driving transistor by turning on a switching transistor coupled to the driving transistor in response to a sensing signal.

8. The method of claim 5 , wherein the sensed current corresponds to an amplitude of the constant current provided by a current source at a front end of an analog-digital converting circuit configured to convert the sensed current into the sensing data.