发明授权
- 专利标题: Wide-angle type zoom lens
- 专利标题(中): 广角式变焦镜头
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申请号: US919770申请日: 1978-06-28
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公开(公告)号: US4200358A公开(公告)日: 1980-04-29
- 发明人: Sadahiko Tsuji , Yasuhisa Sato
- 申请人: Sadahiko Tsuji , Yasuhisa Sato
- 申请人地址: JPX Tokyo
- 专利权人: Canon Kabushiki Kaisha
- 当前专利权人: Canon Kabushiki Kaisha
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX52/81570 19770708
- 主分类号: G02B15/167
- IPC分类号: G02B15/167 ; G02B15/17 ; G02B15/18
摘要:
A zoom lens having a focal length range of about 1:9.5 with a relative aperture of 1:1.4 and whose minimum focal length is made shorter than has heretofore been possible to correspond to an image angle of 56.degree. or more, while good stability of aberration correction is maintained throughout the extended zooming range at the increased relative aperture with limitation of the overall dimensions to a minimum. The lens is suitable for cine cameras of small size and includes a positive first group of four lens elements movable for focusing, negative second and negative third groups axially movable to effect zooming, a positive fourth group acting in afocal manner, and a positive fifth group having an image forming function, the first, fourth and fifth groups being stationary during zooming.
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