Organic light emitting display device and driving method of the same

An OLED display device comprising:

• a plurality of pixels, each of the pixels including an organic light emitting diode and a pixel driving circuit that drives the organic light emitting diode,
• each of the pixel driving circuit including:
• a driving TFT configured to control driving of the organic light emitting diode and including a gate node as a first node, a drain node as a second node, and a source node as a third node;
• first, second, third, fourth, and fifth switching TFTs electrically connected to the driving TFT;
• a storage capacitor connected to a fourth node as a drain node of the fifth switching TFT and configured to store a voltage to be applied to the driving TFT;
• and
• a coupling capacitor configured to supply a bootstrapped voltage to the first node as the gate node of the driving TFT,
• the pixel driving circuit operates in a period that includes:
• an initialization period in which an initialization voltage Vinit is supplied to the fourth node and a high-potential voltage VDD is supplied to the first node;
• a sampling period in which a data voltage Vdata is supplied to the third node and a threshold voltage Vth of the driving TFT is scanned when the high-potential voltage VDD is decreased to the data voltage Vdata in the first node;
• a voltage holding section in which the first through fifth switching TFTs are turned off and each of the first through fourth nodes are floated;
• a connection section in which the third node and the fourth node are electrically connected to each other and the data voltage Vdata held in the third node is supplied to the fourth node;
• and
• an emission section in which a voltage of the first node is rapidly increased by the coupling capacitor and a voltage of the source node of the driving TFT is also increased according to the increased voltage of the first node, so that a delay of a current involved in emission by the organic light emitting diode is minimized.