A light emitting device includes multiple light units each of which includes a semiconductor light source, and a current supply control means for controlling supply of current to the semiconductor light source. A control unit includes a control signal generation means for generating and providing a control signal. The light emitting device also includes switching means for controlling feeding from a DC power source to a corresponding one of the light units in response to the control signal. Each of the switching means is coupled to a corresponding one of the light units through a feed line.