Patent ID: 8203288
Filing Date: 2012-06-19
Classification: H05B,Y02B

Abstract:
1. A light emitting diode array driving apparatus for driving a light emitting diode array having a plurality of light emitting diodes connected in series, in parallel, or in a mixed manner of serial and parallel connections, said apparatus comprising: a direct current-direct current converting part for converting an input voltage into a voltage appropriate for driving the light emitting diode array; a current/voltage detecting part for detecting a magnitude of a first current flowing through a switching element of the direct current-direct current converting part to correspondingly output a first current detection voltage, detecting a magnitude of a voltage across the light emitting diode array to correspondingly output a light emitting diode array detection voltage, and detecting a magnitude of a current flowing through the light emitting diode array to correspondingly output a second current detection voltage; and a constant current controlling part for controlling an on/off duty of the switching element according to the first current detection voltage, the second current detection voltage, and the light emitting diode array detection voltage detected by the current/voltage detecting part, wherein the constant current controlling part includes a pulse width modulation integrated circuit including when an overvoltage is applied to the light emitting diode array or the light emitting diode array is to be turned off by an external dimming control signal, the comparison voltage setter sets the comparison voltage to a value lower than a lower limit of the sawtooth wave voltage.