Patent ID: 8405325

Claim:
An LED lighting power source for a headlamp that is provided for each of left and right headlamps of a vehicle, and independently light respective light-emitting units for the left and right headlamps, the light-emitting units each including one or a plurality of LEDs, said power source comprising: a supplying unit for supplying the electric power supplied from a battery to the light-emitting unit for a vehicle headlamp; a current detecting unit for detecting the current flowing to the light-emitting unit to which the electric power is supplied by the supplying unit; a current setting unit for setting a target current of the current flowing to the light-emitting unit; and a current control unit for controlling the supplying unit such that the current detected by the current detecting coincides with the target current, wherein the current setting unit increases the target with the passage of time by taking a period of 5 ms to 4000 ms, after the supplying unit has begun to supply electric power to the light-emitting unit, wherein the current control unit sequentially increases the current flowing to the light-emitting unit by controlling the supplying unit in accordance with the target current increasing with the passage of time to cause the current to attain the steady-state lighting current of the lighting-emitting unit.