Patent ID: 6963446

Claim:
An epi-illumination apparatus comprising, in the following order from a light source device side: a first imaging lens which forms an image of the light source; and a field lens which projects said image of the light source toward an object to be illuminated; wherein either one of a first magnification varying unit or a second magnification varying unit is selectively disposed between said first imaging lens and said field lens in order to vary a magnification of said image of the light source, said first magnification varying unit including a first aperture stop and a second imaging lens that is disposed in the field lens side of the first aperture stop, and said second magnification varying unit including a second aperture stop and a third imaging lens that is disposed in the first imaging lens side of the second aperture stop; and wherein said first aperture stop in said first magnification varying unit is disposed at a focal point position of said first imaging lens, and said second aperture stop in said second magnification varying unit is disposed at a combined focal point position of said first and third imaging lenses.