Light source device and projector

Abstract

In one embodiment, a light source device comprises an arc tube having a first sealing portion extending from a light emission portion. A reflection mirror is attached to neighbor the first sealing portion and has a concave reflection surface. A container accommodates the arc tube and the reflection mirror. A branch portion has a first opening which branches a part of a cooling air flowing within the container to guide the cooling air to the arc tube. First and second duct portions are each connected to the branch portion. The first and second duct portions extend along a center axis of a light reflected by the reflection mirror such that the air flows in a direction opposite to a traveling direction of the light reflected by the reflection surface. A guiding member directs the air toward the first or second duct portion by moving by its own weight.

What is claimed is: 
     
         1 . A light source device comprising:
 an arc tube having a light emission portion and a first sealing portion extending from an end of the light emission portion;   a reflection mirror attached to neighbor the first sealing portion and having a substantially concave reflection surface for reflecting a light emitted from the light emission portion;   a container which accommodates the arc tube and the reflection mirror;   a branch portion having a first opening which branches a part of a cooling air flowing within the container to guide the part of the cooling air to the arc tube;   a first duct portion and a second duct portion each connected to the branch portion, wherein the first duct portion and the second duct portion extend along a center axis of a light reflected by the reflection mirror such that the cooling air can flow in a direction opposite to a traveling direction of the light reflected by the reflection surface; and   a guiding member which directs the cooling air toward the first duct portion or the second duct portion positioned above the arc tube by moving by its own weight.   
     
     
         2 . The light source device according to  claim 1 , wherein the first duct portion and the second duct portion are disposed opposed to each other with a center of the arc tube interposed between the first duct portion and the second duct portion. 
     
     
         3 . The light source device according to  claim 1 , further comprising:
 a second opening that is open to the arc tube and disposed at a position shifted toward a traveling direction side from an opening end of the reflection mirror; and   a metal plate-shaped member attached to an upper surface over the second opening such that the cooling air is reflected by the metal plate-shaped member toward the light emission portion.   
     
     
         4 . A projector comprising:
 the light source device according to  claim 1 ;   a light modulation device which modulates a light emitted from the light source device and forms an image light; and   a projection device which projects the image light.