发明名称 |
OPTICAL SYSTEM AND OPTICAL APPARATUS HAVING THE SAME |
摘要 |
An optical system includes at least one lens unit having a negative refractive power disposed closer to an object side than an aperture portion. The lens unit having a negative refractive power includes at least one positive lens and one negative lens. The ratio between the numbers of positive lenses and negative lenses included in the lens unit having a negative refractive power is appropriately set. The lens unit having a negative refractive power includes a plurality of negative lenses each having an appropriate Abbe number and relative partial dispersion and a positive lens having an appropriate Abbe number. A negative lens having the highest dispersion among the negative lenses is located in an appropriate position. |
申请公布号 |
US2012250168(A1) |
申请公布日期 |
2012.10.04 |
申请号 |
US201213436244 |
申请日期 |
2012.03.30 |
申请人 |
EGUCHI KAORU;HIASA NORIHITO;CANON KABUSHIKI KAISHA |
发明人 |
EGUCHI KAORU;HIASA NORIHITO |
分类号 |
G02B13/04 |
主分类号 |
G02B13/04 |
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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