发明授权
- 专利标题: Real-image finder having variable power
- 专利标题(中): 具有可变功率的实像取景器
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申请号: US506633申请日: 1995-07-25
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公开(公告)号: US5694244A公开(公告)日: 1997-12-02
- 发明人: Tetsuya Abe , Takayuki Ito , Sachio Hasushita , Moriyasu Kanai
- 申请人: Tetsuya Abe , Takayuki Ito , Sachio Hasushita , Moriyasu Kanai
- 申请人地址: JPX Tokyo
- 专利权人: Asahi Kogaku Kogyo Kabushiki Kaisha
- 当前专利权人: Asahi Kogaku Kogyo Kabushiki Kaisha
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX6-178798 19940729
- 主分类号: G03B13/06
- IPC分类号: G03B13/06 ; G02B13/18 ; G02B15/16 ; G02B15/167 ; G02B15/173 ; G02B25/00 ; G02B23/00 ; G02B15/14
摘要:
A real-image finder having variable power includes an objective lens system of positive power, a condenser lens, and an ocular lens system. The objective lens system includes a first positive lens group, a second negative lens group, and a third positive lens group from an object side towards an image side. The second lens group is moved toward an image side and the third lens group is moved toward an object side, when the magnification changes from a wide angle side to a telephoto side. Thus, the distance between the first and second lens groups increases, the distance between the second and third lens groups decreases, and the distance between the third lens group and the condenser lens increases. The real-image finder meets the requirements defined by the relationships 0.5
公开/授权文献
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