Invention Grant
- Patent Title: Zoom lens system
- Patent Title (中): 变焦镜头系统
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Application No.: US12185215Application Date: 2008-08-04
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Publication No.: US07791819B2Publication Date: 2010-09-07
- Inventor: Masaru Eguchi
- Applicant: Masaru Eguchi
- Applicant Address: JP Tokyo
- Assignee: Hoya Corporation
- Current Assignee: Hoya Corporation
- Current Assignee Address: JP Tokyo
- Agency: Greenblum & Bernstein P.L.C.
- Priority: JP2007-202642 20070803
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
A zoom lens system includes a negative first lens group, a positive second lens group, and a positive third lens group, in this order from the object. Upon zooming from the short focal length extremity to the long focal length extremity, the distance between the negative first lens group and the positive second lens group decreases, and the distance between the positive second lens group and the positive third lens group increases. The negative first lens group includes a negative first lens element, a negative second lens element having a weaker negative refractive power, and a positive third lens element, in this order from the object. The second lens element of the negative first lens group satisfies the following condition: 0
Public/Granted literature
- US20090034092A1 ZOOM LENS SYSTEM Public/Granted day:2009-02-05
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