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Real-image finder optical system and apparatus using the same

  • US 6,078,411 A
  • Filed: 02/25/1999
  • Issued: 06/20/2000
  • Est. Priority Date: 02/26/1998
  • Status: Expired due to Term
First Claim
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1. In a real-image finder optical system comprising:

  • an objective optical system for a finder;

    an image-inverting optical system for erecting an object image formed by said objective optical system; and

    an ocular optical system;

    wherein an optical path for the finder is separate from an optical path for photography;

    the improvement wherein said objective optical system has a plurality of lens units, wherein when zooming from a wide-angle end to a telephoto end is performed, a spacing between said plurality of lens units is changed, andsaid image-inverting optical system has a plurality of reflecting surfaces, wherein, of said plurality of reflecting surfaces, at least one reflecting surface that is placed closer to said ocular optical system than said object image is formed from a curved reflecting surface having a power, said image-inverting optical system having a rotationally asymmetric surface that corrects rotationally asymmetric decentration aberrations produced by said curved reflecting surface.

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