发明名称 |
Vari-focal optical system |
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.
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申请公布号 |
US2005030641(A1) |
申请公布日期 |
2005.02.10 |
申请号 |
US20040885859 |
申请日期 |
2004.07.08 |
申请人 |
KUBA KEIICHI;MINAKATA HIROYUKI |
发明人 |
KUBA KEIICHI;MINAKATA HIROYUKI |
分类号 |
G02B15/167;G02B13/00;G02B13/18;G02B15/177;H04N5/225;(IPC1-7):G02B15/14 |
主分类号 |
G02B15/167 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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