Illumination apparatus and projector type display apparatus using the same

An illumination apparatus comprising:

• a light source group in which a plurality of light source sections, each constituted by a luminous body and a reflector comprising a parabolic surface for emitting a luminous flux from said luminous body to a front side of an optical axis, are arranged;
• an integrator section, constituted by at least two integrator plates, for homogenizing in a cross section perpendicular to said optical axis a quantity of light emitted from said light source group, said integrator section being arranged in said optical axis direction;
• and
• a parallel luminous flux approaching optical system comprising a plurality of first lens groups corresponding to said plurality of light source sections in said light source group substantially one by one and functioning to cause each of said luminous fluxes from said plurality of light source sections to form a focal point once;
• and at least one second lens group, disposed downstream said focal point, for emitting said luminous fluxes from said light source group toward said integrator section as a substantially parallel luminous flux;
• wherein the optical axis of the whole illumination apparatus and optical axes of said light source section and first lens group forming a pair are substantially parallel to each other and satisfy the following conditional expression (1):
• Saxis>Faxis (1)
• where
• Saxis is the distance between the optical axis of the whole illumination apparatus and the optical axis of the light source section;
• and
• Faxis is the distance between the optical axis of the whole illumination apparatus and the optical axis of the first lens group.

An illumination apparatus comprising:

• a light source group in which a plurality of light source sections, each constituted by a luminous body and a reflector comprising an ellipsoidal surface having one focal point located near a center of gravity of said luminous body, are arranged;
• an integrator section, constituted by at least two integrator plates, for homogenizing a quantity of light emitted from said light source group, said integrator section being arranged in an optical axis direction of said light;
• and
• at least one mirror element, having a reflecting surface near the other focal point of said ellipsoidal surface of at least one said reflector, for reflecting a luminous flux from said light source group toward said integrator section;
• wherein said illumination apparatus as a whole has an optical axis forming a predetermined angle with an optical axis of said at least one reflector;
• wherein at least one lens for emitting said luminous flux from said mirror element toward said integrator section as a substantially parallel luminous flux is disposed on said mirror element side of said integrator section, and
• wherein said illumination apparatus as a whole has an optical axis intersecting an axis of the luminous flux from said at least one reflector from each other in the vicinity of the incident surface of said lens.