Organic light emitting display device including a sensing unit to measure at least one of current and voltage, and method of driving the same

An organic light emitting display device, comprising:

• pixels connected to scan lines, data lines, and emission control lines and configured to emit light in response to amounts of current that flow from a first driving power source to a second driving power source;
• a sensing unit connected between the first driving power source and the pixels or between the second driving power source and the pixels and configured to measure at least one of current and voltage;
• a controller configured to generate a control signal in response to at least one of the current and the voltage measured by the sensing unit;
• a timing controller configured to supply a plurality of emission start signals with different widths in a single frame period in response to the control signal when the organic light emitting display device is driven at a low frequency;
• and
• an emission driver configured to supply emission control signals to the emission control lines in response to the emission start signals,
• wherein, when the organic light emitting display device is driven at the low frequency, the single frame period is divided into a plurality of sub-periods with a same width and emission periods of the pixels in the plurality of sub-periods are set to be different from each other in response to the different widths of the emission start signals,
• wherein the sensing unit comprises a sensing resistor, and
• wherein the controller comprises:
• a converter configured to convert voltage values from the sensing resistor into current values;
• a comparator configured to accumulate the current values from the converter in an emission period of a first one of the plurality of sub-periods in the single frame period, to store the accumulated current values as a reference value, and to generate the control signal when the reference value is equal to the current values from the converter in other sub-periods of the plurality of sub-periods;
• and a storage unit configured to store the reference value.