发明名称 |
Rear attachment lens and imaging optical system including the same |
摘要 |
<p>A rear attachment lens detachably attached to a main lens system at an image side thereof to lengthen a focal length includes a negative lens disposed such that, when L is a distance between a lens surface closest to an object side and a lens surface closest to an image side in the rear attachment lens, the negative lens is within an area in which a distance from the lens surface closest to the object side to the negative lens is in the range of 0.5L to 1.0L. When νdn1 is an Abbe number of a material of the negative lens with respect to the d-line and θgFn1 is a partial dispersion ratio of the material of the negative lens with respect to the g-line and the F-line, the following conditions are satisfied: 10<νdn1<230.020<θgFn1-0.6438+0.001682*νdn1<0.100.</p> |
申请公布号 |
EP2312341(A3) |
申请公布日期 |
2012.01.18 |
申请号 |
EP20100176325 |
申请日期 |
2010.09.13 |
申请人 |
CANON KABUSHIKI KAISHA |
发明人 |
SUGITA, SHIGENOBU;EGUCHI, KAORU |
分类号 |
G02B1/00;G02B15/08;G02B27/00 |
主分类号 |
G02B1/00 |
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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