Light source device and projection type display capable of enclosing fragment herein in case of burst of discharge lamp during lighting

Abstract

It is an object to obtain a light source device and a projection type display device in which a fragment can be completely enclosed therein even if a discharge lamp bursts during lighting. During normal lighting of a discharge lamp ( ), an internal space of a light source device ( ) and an external space are spatially connected to each other through a vent hole ( ) formed on a cutoff valve mechanism ( ) and a vent hole ( ) formed on a concave reflecting mirror ( ). Cooling air is introduced and discharged between the internal space and the external space so that the discharge lamp ( ) is cooled down. When the discharge lamp ( ) bursts during lighting for some reason, a very strong impulsive pressure wave is generated in a moment of the burst. The pressure wave presses a movable valve ( ) provided in the cutoff valve mechanism ( ) through the vent hole ( ). By the pressing carried out with the pressure wave, the movable valve ( ) is pushed up in a direction of an arrow (K ), thereby closing the vent hole ( ).