摘要 |
A light source device includes: a light emitting tube; a reflecting mirror; and a tubular member disposed on a forward side of light emission of the reflecting mirror, and surrounding the light emitting tube, the tubular member has a pair of air circulating units communicating inside and outside of the tubular member and adapted to allow introduction of external air from the forward side toward a backward side of the light emission in a vertically symmetrical manner on a center axis of the light emitting tube, inside the air circulating unit there is disposed a air flow guide member, and the air flow guide member is pivoted rotatably around a predetermined rotational axis with respect to the air circulating unit under own weight of the air flow guide member, and rotates to thereby open and block at least a part of a flow passage inside the air circulating unit. |