A light source device has a light shielding member having an aperture, a light source arranged on one side of the light shielding member, and a converging member arranged relatively with respect to the light source and the light source to thereby converge light emitted from the light source in the aperture or in a vicinity of the aperture. Another type of light source device has a single light source, and a converging member for converging light from the light source to thereby distribute the light to at least two points. Still another type of light source device has a light source, and a reflecting mirror arranged to enclose a side of a light emission direction of the light source, the reflecting mirror reflecting light emitted from the light source in a direction except the light source so that the light is radiated outside.