Invention Grant
- Patent Title: Zoom lens and image pickup apparatus having the same
- Patent Title (中): 具有相同的变焦镜头和摄像装置
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Application No.: US14645942Application Date: 2015-03-12
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Publication No.: US09588323B2Publication Date: 2017-03-07
- Inventor: Yuki Tatenuma , Masakazu Kodaira , Takahiro Yoshimi
- Applicant: CANON KABUSHIKI KAISHA
- Applicant Address: JP Tokyo
- Assignee: CANON KABUSHIKI KAISHA
- Current Assignee: CANON KABUSHIKI KAISHA
- Current Assignee Address: JP Tokyo
- Agency: Carter, DeLuca, Farrell & Schmidt, LLP
- Priority: JP2014-054785 20140318
- Main IPC: G02B15/17
- IPC: G02B15/17 ; G02B15/173 ; G02B15/177 ; G02B15/28 ; G02B15/26 ; G02B15/24

Abstract:
The zoom lens according to the present invention includes in order from an object side to an image side: a first lens unit; a second lens unit; a third lens unit; an aperture stop; and a fourth lens unit; wherein a partial dispersion ratio θLm of a material of a positive lens Lm formed of a material having a highest partial dispersion ratio, which is contained in a rear group, a distance d from the aperture stop to an image plane, a distance dLm from the aperture stop to a positive lens Lm, an average value νRfp of Abbe constants of materials of positive lenses contained in a front group, an average value θRfp of partial dispersion ratios thereof, an average value νRfn of Abbe constants of materials of negative lenses contained in the front group, and an average value θRfn of partial dispersion ratios thereof are each appropriately set.
Public/Granted literature
- US20150268456A1 ZOOM LENS AND IMAGE PICKUP APPARATUS HAVING THE SAME Public/Granted day:2015-09-24
Information query
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