公开(公告)号：US20120307371A1

公开(公告)日：2012-12-06

申请号：US13483987

申请日：2012-05-30

申请人： Katsuhiro TAKAMOTO ,  Kazuhiko INOUE ,  Sadanobu IMAMURA ,  Kohei WATARU

发明人： Katsuhiro TAKAMOTO ,  Kazuhiko INOUE ,  Sadanobu IMAMURA ,  Kohei WATARU

IPC分类号： G02B15/14

CPC分类号： G02B13/16 ,  G02B15/14

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.

摘要翻译： 通过整个系统的移动实现聚焦的可变焦距透镜系统具有作为焦距变化透镜组的第二至第四透镜组和作为距离补偿透镜组的第一透镜组。 第二至第四透镜组在光轴方向上分别移动以改变组与组的距离，从而改变整个系统的焦距。 在聚焦期间，第一透镜组沿光轴方向移动，使得当投射距离从远距离变化到近距离时，曲率变化到下侧。