Organic light emitting diode display and driving method thereof

A method of driving an organic light emitting diode display, the display including a light emitting cell connected between a high-level voltage source and a first node, and a driving transistor connected between the first node and a ground voltage source to control current flow in the light emitting cell by using a voltage applied to a gate terminal of the driving transistor, the method comprising:

• applying a data voltage of first polarity to the gate terminal of the driving transistor to shift a threshold voltage of the driving transistor from a reference value to the voltage of first polarity;
• shifting the threshold voltage of the driving transistor from the voltage of first polarity to a voltage of second polarity by supplying a compensation voltage of second polarity different from the first polarity, to the gate terminal of the driving transistor;
• and
• restoring the threshold voltage of the driving transistor to the reference value by supplying a constant current to the gate terminal of the driving transistor from a constant current source.

An organic light emitting diode display, comprising:

• a light emitting cell connected between a high-level voltage source and a first node;
• a driving transistor connected between the first node and a ground voltage source to control a current flow at the light emitting cell, using a voltage applied to a gate terminal of the driving transistor;
• a data driving circuit configured to apply a data voltage to the gate terminal of the driving transistor to increase a threshold voltage of the driving transistor to a value greater than a reference value;
• a compensation circuit configured to supply a compensation voltage, which is different from the data voltage, to the gate terminal of the driving transistor to reduce the threshold voltage of the driving transistor to a value less than the reference value;
• and
• the compensation circuit configured to supply a constant current to the gate terminal of the driving transistor to restore the threshold voltage of the driving transistor to the reference value.