Organic light emitting display and method for driving the same

An organic light emitting display, comprising:

• a first transistor including a gate electrode connected to a scan line, a first electrode connected to a data line, and a second electrode connected to a first node;
• a first capacitor including a first electrode connected to the first node and a second electrode connected to a second node;
• a second transistor including a gate electrode connected to the second node, a first electrode connected to a first power voltage, and a second electrode connected to a third node;
• a third transistor including a gate electrode connected to a compensation control line, a first electrode connected to the second node, and a second electrode connected to the third node;
• a fourth transistor including a gate electrode connected to a sensing control line, a first electrode connected to the third node, and a second electrode connected to a sensing line;
• and
• an organic light emitting element including an anode electrode connected to the third node and a cathode electrode connected to a second power voltage.

A method for driving an organic light emitting display, the display including a plurality of pixels, each of the pixels including a first node to which a data voltage is applied through a switching transistor that is turned on by a scan signal of a gate-on voltage, a third node connected to an anode electrode of an organic light emitting element, a second node connected to a gate electrode of a drive transistor that controls drive current transferred from a first power voltage to the third node, and a first capacitor connected between the first node and the second node, the method comprising:

• initializing a voltage of the third node;
• compensating a threshold voltage of the drive transistor by connecting the third node to the second node;
• applying a sensing voltage to the first node and sensing drive information of the drive transistor based on sensing current formed at the third node by the sensing voltage;
• and
• applying a data voltage according to compensated image data in which the sensed drive information is reflected, wherein the organic light emitting element emits light based on the applied data voltage.