IMAGE-FORMING OPTICAL SYSTEM
3 Assignments
0 Petitions
Accused Products
Abstract
A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a single prism. When image-side three surfaces of the prism are defined as a surface A, a surface B and a surface C in order from the image plane side thereof, at least one of the surfaces B and C has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The optical system leads light rays from an object to the image plane without forming an image in the prism and has a pupil in the prism. The surface A is a transmitting surface through which rays exit from the prism. The surfaces B and C are internally reflecting surfaces, which are positioned to face each other to form a Z-shaped optical path.
4 Citations
30 Claims
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1-29. -29. (canceled)
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30. A catadioptric system comprising:
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at least one lens; and at least three reflecting surfaces; wherein when said three reflective surfaces are defined as a first reflecting surface, a second reflecting surface, and a third reflective surface in order along a light path, these reflecting surfaces are positioned so that a line connecting a point of reflection on the first reflecting surface, a point of reflection on the second reflecting surface and a point of reflection on the third reflecting surface does not intersect itself; at least one of the said first and second reflecting surfaces being a rotationally symmetric aspherical surface; said first reflecting surface and said third reflecting surface being connected to each other with a step interposed therebetween; said first reflecting surface and said third reflecting surface facing approximately in a same direction; and wherein a lens is positioned in an entrance-side light path entering a reflecting optical system formed from said three reflecting surfaces, and another lens is positioned in an exit-side light path exiting from said reflecting optical system.
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Specification