Patent attributes
A light source device includes a discharge lamp and a reflection mirror having a plurality of concave curved surfaces. Each of the plurality of concave curved surfaces is an ellipsoidal surface. A first focal point of each of the ellipsoidal surfaces is disposed at the light emitting center of the discharge lamp. A second focal point of each of the ellipsoidal surfaces is disposed, when viewed from a predetermined first direction perpendicular to a system optical axis passing through the light emitting center, on the opposite side of the system optical axis to the ellipsoidal surface, and when viewed from a second direction perpendicular to the system optical axis and the first direction, on the side where the ellipsoidal surface is present with reference to the system optical axis.