Patent ID: 8710417

Claim:
A stable light source device comprising: a light source that emits light; a pinhole that constricts optical flux emitted from the light source; a first integrating element inside which optical flux from the pinhole is multiply reflected; a light detection sensor that monitors a light amount; a control section that controls the light source on the basis of the light amount monitored by the light detection sensor and that makes the light amount to be consistent; an aperture that is formed in the first integrating element and that emits light outside the first integrating element; a diffusion-transmission member that is disposed at a light emission side of the aperture; a branching section that is disposed at a light emission side of the diffusion-transmission member, and that branches incident light towards a plurality of light emission portions; and neutral density filters that are provided at the plurality of light emission portions, transmitted light amounts of the neutral density filters respectively differing such that light amounts at the light emission portions are respectively different.