发明名称 |
Zoom lens and image pickup apparatus including the same |
摘要 |
A zoom lens includes a first lens unit having a positive refractive power which does not move for zooming; a second lens unit having a negative refractive power which moves during zooming; a third lens unit having a negative refractive power which moves during zooming; a fourth lens unit having a positive refractive power which moves during zooming; and a fifth lens unit having a positive refractive power which does not move for zooming. Air intervals (L2w and L2t) between the second lens unit and the third lens unit at a wide-angle end and at a telephoto end, respectively, an air interval (L3w) between the third lens unit and the fourth lens unit at the wide-angle end, a focal length (f1) of the first lens unit, and a combined focal length (f23w) of the second lens unit and the third lens unit at the wide-angle end are appropriately set. |
申请公布号 |
US8743469(B2) |
申请公布日期 |
2014.06.03 |
申请号 |
US201213446234 |
申请日期 |
2012.04.13 |
申请人 |
Canon Kabushiki Kaisha |
发明人 |
Nakamura Tomoyuki;Takemoto Shoichi |
分类号 |
G02B15/14 |
主分类号 |
G02B15/14 |
代理机构 |
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代理人 |
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主权项 |
1. A zoom lens, comprising, in order from an object side to an image side:
a first lens unit having a positive refractive power which does not move for zooming; a second lens unit having a negative refractive power which moves during zooming; a third lens unit having a negative refractive power which moves during zooming; a fourth lens unit having a positive refractive power which moves during zooming; and a fifth lens unit having a positive refractive power which does not move for zooming, wherein the following conditions are satisfied:
5<L2w/L2t<50;0.6<L2w/L3w<2.5; and10<|f1/f23w|<25,where L2w and L2t represent air intervals between the second lens unit and the third lens unit at a wide-angle end and at a telephoto end, respectively, L3w represents an air interval between the third lens unit and the fourth lens unit at the wide-angle end, f1 represents a focal length of the first lens unit, and f23w represents a combined focal length of the second lens unit and the third lens unit at the wide-angle end.
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地址 |
JP |