Patent ID: 8791935

Claim:
An organic electroluminescent display device comprising: a pixel unit comprising a plurality of scan lines arranged in a row direction, a plurality of data lines arranged in a column direction, and a plurality of pixels formed at intersections between the plurality of scan lines and the plurality of data lines; a power supply unit to generate and to output a direct current (DC) power supply from an external power source; and a DC-DC converter to receive the DC power supply from the power supply unit, to generate a first power supply voltage and a second power supply voltage, and to supply the first power supply voltage and the second power supply voltage to the pixel unit, wherein the DC-DC converter comprises: a boost converter to receive the DC power supply from the power supply unit and to generate the first power supply voltage comprising a first capacitor having a first terminal electrically connected to a first power supply voltage output terminal and a second terminal; a buck-boost converter to receive the DC power supply from the power supply unit and to generate the second power supply voltage comprising a second capacitor having a first terminal electrically connected to a second power supply voltage output terminal and a second terminal electrically connected to the second terminal of the first capacitor such that the first power supply is coupled to the second power supply through the first and second capacitors; and an output control unit to measure a temperature of the DC-DC converter, to compare the temperature of the DC-DC converter with a reference temperature, to stop output of the first power supply voltage of the boost converter and the second power supply voltage of the buck-boost converter if the temperature of the DC-DC converter is equal to or greater than the reference temperature, and to maintain a state where the output of the first and second power supply voltages are stopped.