发明授权
- 专利标题： Compact zoom lens with short back focal distance
- 专利标题（中）： 紧凑型变焦镜头具有短焦距
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申请号： US752139申请日： 1985-07-03
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公开(公告)号： US4652091A公开(公告)日： 1987-03-24
- 发明人: Kouji Oizumi , Yasuhisa Sato , Yasuyuki Yamada , Hiroki Nakayama
- 申请人： Kouji Oizumi , Yasuhisa Sato , Yasuyuki Yamada , Hiroki Nakayama
- 专利权人： Canon Kabushiki Kaisha
- 当前专利权人： Canon Kabushiki Kaisha
- 优先权： JPX59-142057 19840709
- 主分类号： G02B15/16
- IPC分类号： G02B15/16 ; G02B15/173 ; G02B15/20 ; G02B15/14
摘要：
A compact zoom lens is constructed with, from front to rear, first, second and third lens units of positive, negative and positive refractive powers, respectively. A diaphragm is positioned in or adjacent the second lens unit. The second lens unit and the diaphragm are stationary. When zooming from the wide angle end to the telephoto end, the first and third lens units are axially moved in such a manner that each of the separations between the first and second lens units and between the second and third lens units is increased monotonically.
公开/授权文献
- US5926183A Efficient rendering utilizing user defined rooms and windows 公开/授权日：1999-07-20