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Single-lens reflex camera provided with eyepiece

  • US 20030156834A1
  • Filed: 11/13/2002
  • Published: 08/21/2003
  • Est. Priority Date: 11/16/2001
  • Status: Active Grant
First Claim
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1. A single-lens reflex camera provided with an eyepiece, comprising:

  • a screen on which an image of an object is projected;

    a plurality of reflecting surfaces for erecting said image projected on said screen; and

    an eyepiece with positive refracting power for observing said image, wherein said eyepiece comprises, in order from an object side, a first lens component with positive refracting power, a second lens component with positive refracting power, and a third lens component with negative refracting power and satisfies the following conditions;

    0.15<

    tan S<

    0.352.00<

    fb/Y<

    5.00−

    0.67<

    f3/f<



    0.25where S is an angle made by a most off-axis chief ray passing through a point on an optical axis with said optical axis, at a distance of 23 mm along said optical axis from an exit surface of said third lens component, and refers to an angle at a diopter of 0 m

    1
    when said eyepiece is moved;

    fb is a length, in terms of air, from said screen to an entrance surface of said first lens component, and refers to a length, in terms of air, at a diopter of 0 m

    1
    when said eyepiece is moved;

    Y is a diagonal length of an image plane on said screen;

    f3 is a focal length of said third lens component; and

    f is a focal length of an entire system extending from said screen to an exit surface of said eyepiece, and refers to a focal length of an entire system at the diopter of 0 m

    1
    when said eyepiece is moved.

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