Organic light emitting display

An organic light emitting display comprising:

• a display panel;
• a data driver supplying a data signal to the display panel;
• a gamma unit supplying a gamma reference voltage to the data driver;
• a timing controller controlling the data driver;
• a power source supply unit converting an external voltage supplied from an outside and outputting a high potential voltage and a low potential voltage through a first power source line and a second power source line;
• a measurement unit measuring a current or a voltage flowing through the first power source line and the second power source line and outputting a measured value;
• and
• a compensation coefficient calculator matching the measured value and a reference value stored in the compensation coefficient calculator to a driving signal supplied from the timing controller and comparing the measured value and the reference value to judge a degree of noise occurring at an output end of the power source supply unit, and calculating first and second compensation coefficients used to distinguishably correct the data signal and the gamma reference voltage according to the degree of noise.