Patent ID: 7712921

Claim:
A light source unit, comprising: an arc tube including, electrodes, sealed sections and a light emitting section in which discharging emission is performed between the electrodes and the sealed sections which are provided at both ends of the light emitting section, the light emitting section having a front side and a rear side; an elliptic reflector including a reflecting surface to reflect a luminous flux radiated from the arc tube in a certain uniform direction; and a secondary reflecting mirror having a reflecting surface disposed so as to oppose the reflecting surface of the elliptic reflector, covering the front side of the light emitting section, and reflecting the luminous flux radiated from the light emitting section toward the elliptic reflector, the sealed sections being provided on the front side and the rear side of the light emitting section, the secondary reflecting mirror being mounted on the front side sealed section of the arc tube as a separate member from the arc tube, and the secondary reflecting mirror being provided with translucency so that an adhering surface can be seen from an outer peripheral surface.