Patent ID: 7736028

Claim:
A light source apparatus comprising: a lamp having a light emitting portion for generating light, the light emitting portion having a predetermined size; a first mirror, which is an ellipsoidal mirror with a first focus, a second focus, and an optical axis passing through the first focus and the second focus, having a first opening and a second opening, the first opening intersecting the optical axis at a point between the first focus and the second focus, the second opening intersecting the optical axis at a point between the first focus and a vertex of the first mirror that is nearer to the first focus, the light emitting portion being placed at the first focus, the first mirror being oriented to reflect the generated light so that the reflected light passes through the first opening and focuses on the second focus; and a second mirror having a size of a predetermined value or larger to substantially reflect all of a portion of the generated light transmitted out of the second opening to the first focus, wherein the second mirror is a spherical mirror, a center of which is placed at the first focus of the first mirror, and the size of the second opening is provided so that a sum of (i) a loss occurring due to the fact that a part of the light reflected by the first mirror fails to pass through a predetermined aperture placed at the second focus, because of the predetermined size of the light emitting portion, and (ii) a loss occurring when the light is reflected by the second mirror and passes through the light emitting portion, because of a predetermined reflectance of the second mirror and a predetermined transmittance of the light emitting portion, becomes substantially minimum.