PROBLEM TO BE SOLVED: To solve the following problem: an element for detecting a rotation position has to be managed with a close tolerance in a configuration for rotating a rotary filter.SOLUTION: A light source device includes: a light source； switching means for switching an optical path for irradiation light, which is emitted from the light source, between first and second optical paths； and an optical filter that is fixedly arranged in the first optical path to filter the irradiation light, which is propagated through the first optical path, to light in a specific wave range.SELECTED DRAWING: Figure 5【課題】回転フィルタを回転させる構成では、回転位置を検知する要素を厳しい公差で管理しなければならない。【解決手段】光源と、光源より射出される照射光の光路を第一の光路と第二の光路との間で切り替える切替手段と、第一の光路に固定配置されており、該第一の光路を伝播する照射光を特定の波長域の光にフィルタリングする光学フィルタとを備える光源装置を提供する。【選択図】図５
