Patent ID: 8648545

Claim:
A control device of a light emitting diode (LED) light emitting device comprising a plurality of LED channels that are formed with a plurality of LED elements, comprising: a DC/DC converter that supplies an output voltage to the plurality of LED channels, the DC/DC converter comprising a power switch; and a reference voltage generator that generates a reference voltage for controlling the output voltage, wherein the reference voltage generator detects a plurality of channel voltages corresponding to an LED voltage drop by a plurality of LEDS of each of the plurality of LED channels and controls the reference voltage so that a minimum value of the plurality of channel voltages agrees with a predetermined minimum reference voltage, and wherein the reference voltage generator comprises a voltage detection unit that detects the plurality of channel voltages and that outputs the minimum value of the detected plurality of channel voltages; and a voltage controller that compares the minimum value and a level of the minimum reference voltage and that increases, if the minimum value is lower than the minimum reference voltage, the reference voltage, and that decreases, if the minimum value is higher than the minimum reference voltage, the reference voltage.