Patent ID: 7495397

Claim:
A drive device for a light emitting diode element, the device comprising: a light emitting diode element circuit part configured to be formed by connecting at least one light emitting diode element based on a predetermined connection form; a power supply unit configured to generate a direct-current (DC) supply voltage for driving the at least one light emitting diode element of the light emitting diode element circuit part for light emission of the light emitting diode element, and apply the DC supply voltage to the light emitting diode element circuit part; a power-supply application on/off unit configured to be provided to turn on/off application of the DC supply voltage to the light emitting diode element circuit part; and a current control circuit part configured to be caused to switch its operation so as to carry out constant current operation if application of the DC supply voltage is in an on-state and carry out voltage keeping operation if application of the DC supply voltage is in an off-state, the constant current operation being to implement variation control of an amount of a drive current that flows through the light emitting diode element circuit part by an amplified output voltage dependent upon a difference between a voltage detection value detected depending on the amount of the drive current and a predetermined reference voltage value, the voltage keeping operation being to keep the amplified output voltage at a predetermined value of which difference from the reference voltage value is within a predetermined range.