发明授权
- 专利标题: Variable-focal-length projection lens system and projection apparatus
- 专利标题(中): 可变焦距投影透镜系统和投影仪
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申请号: US13483987申请日: 2012-05-30
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公开(公告)号: US08699139B2公开(公告)日: 2014-04-15
- 发明人: Katsuhiro Takamoto , Kazuhiko Inoue , Sadanobu Imamura , Kohei Wataru
- 申请人: Katsuhiro Takamoto , Kazuhiko Inoue , Sadanobu Imamura , Kohei Wataru
- 申请人地址: JP Tokyo
- 专利权人: Konica Minolta Advanced Layers, Inc.
- 当前专利权人: Konica Minolta Advanced Layers, Inc.
- 当前专利权人地址: JP Tokyo
- 代理机构: Cozen O'Connor
- 优先权: JP2011-120823 20110530
- 主分类号: G02B9/00
- IPC分类号: G02B9/00 ; G02B15/14 ; G02B13/16
摘要:
A variable-focal-length lens system for projection which achieves focusing by movement of the entire system has a second to a fourth lens group as focal-length-varying lens groups and a first lens group as a distance-compensation lens group. The second to fourth lens groups individually move in the optical axis direction to vary the group-to-group distances so as to vary the focal length of the entire system. During focusing, the first lens group moves in the optical axis direction such that, as the projection distance varies from a remote distance to a close distance, curvature of field varies to the under side.