Two of four light sources have canceling characteristics with respect to color nonuniformity, and the other two light sources have canceling characteristics with respect to color nonuniformity. A light emission stop detector detects that each of the light sources stops emitting light by blowing its value for example, and feeds, if a certain light source stops emitting light, information indicating that the light source stops emitting light to an energization controller. The energization controller stops, when it receives the information indicating that a certain light source stops emitting light, the energization to a light source paired with the certain light source and puts out the light source.