Reflecting optical imaging apparatus using spherical reflectors and producing an intermediate image

A reflection reduction projection optical apparatus comprising:

• a first optical system for forming a virtual image of approximately magnification 1 of an object of an object plane;
• a second optical system for forming a reduced real image from the virtual image formed by said first optical system;
• and
• a third optical system for forming an image of approximately one-to-one magnification from the real image formed by said second optical system;
• said first optical system having a concave reflecting surface as a first reflecting surface and a convex reflecting surface as a second reflecting surface disposed substantially concentrically, and a predetermined optic axis;
• the object plane and image plane of said first optical system lying in a plane substantially containing the center of concentricity and perpendicular to the optic axis of said first optical system or a plane
• optically equivalent to said plane;
• said second optical system having a convex reflecting surface as a third reflecting surface and a concave reflecting surface as a fourth reflecting surface disposed substantially concentrically, a fifth reflecting surface disposed substantially at the image position by said third reflecting surface and said fourth reflecting surface, and a predetermined optic axis;
• said third optical system having a concave reflecting surface as a sixth reflecting surface, and a predetermined optic axis;
• the object plane and image plane of said third optical system lying in a plane substantially containing the center of curvature of said sixth reflecting surface and perpendicular to the optic axis of said third optical system or a plane optically equivalent to said plane.