LIGHT SOURCE DEVICE

摘要

A light source device (10) comprising a short arc discharge lamp (20) having a pair of electrodes (23, 24) arranged opposite within a light emitting bulb (21) of a discharge container, and a concave reflector (11) arranged in such a way that its optical axis is coincident with an arc direction of the discharge lamp (20), wherein a distance between the electrodes in the short arc discharge lamp (20) is 4.0 mm or less; the light emitting bulb (21) of the short arc discharge lamp (20) is made such that its inner surface (26a) and outer surface (26b) are spherical surfaces with the center (A) of the arc being applied as a center in at least a specific portion; and said specific portion is a region in which a solid angle with the center (A) of the arc being applied as an apex and the optical axis (L) of the concave reflector (11) being applied as a central axis is at least 3 sr or more in the front region positioned in front of a critical straight line (D) connecting a point (Y), where an extension line of a virtual straight line (N) connecting any point (M) on the front outer edge of the concave reflector (11) with the center (A) of the arc intersects the outer surface (26b) of the bulb wall in the light emitting bulb (21), with the center (A) of the arc. <IMAGE>