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41. 发明授权

US07042651B2 Vari-focal optical system 有权
标题翻译：变焦光学系统
公开(公告)号：US07042651B2
公开(公告)日：2006-05-09
申请号：US10885859
申请日：2004-07-08
申请人： Keiichi Kuba , Hiroyuki Minakata
发明人： Keiichi Kuba , Hiroyuki Minakata
IPC分类号： G02B15/14
CPC分类号： G02B15/177
摘要： A vari-focal optical system having a composition comprising at least a first negative lens unit, a second positive lens unit, a third negative lens unit and a fourth positive lens unit, and changes a magnification from a wide position to a tele position by moving at least the second lens unit and the third lens unit. This optical system is configured to have a short total length and reserve sufficient airspaces for the magnification change by locating a front principal point of the second lens unit on the object side of the second lens unit.
摘要翻译：具有至少包括第一负透镜单元，第二正透镜单元，第三负透镜单元和第四正透镜单元的组合的变焦光学系统，并且通过移动来将宽广位置的倍率改变为远摄位置至少第二透镜单元和第三透镜单元。该光学系统被配置为具有短的总长度，并且通过将第二透镜单元的前主点定位在第二透镜单元的物体侧上来为放大率改变保留足够的空间。

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