Invention Grant
- Patent Title: Zoom lens and information device incorporating the same
- Patent Title (中): 变焦镜头和包含相机的信息设备
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Application No.: US13564287Application Date: 2012-08-01
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Publication No.: US08638503B2Publication Date: 2014-01-28
- Inventor: Yohei Takano , Hiromichi Atsuumi
- Applicant: Yohei Takano , Hiromichi Atsuumi
- Applicant Address: JP Tokyo
- Assignee: Ricoh Company, Ltd.
- Current Assignee: Ricoh Company, Ltd.
- Current Assignee Address: JP Tokyo
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2011-172375 20110805; JP2011-172376 20110805
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
A zoom lens includes first to fifth lens groups having positive, negative, negative, positive, and positive refractive power, respectively. The third lens group includes a single negative meniscus lens with a concave surface on an object side, to move along the optical axis for focusing. When zooming from a wide angle end to a telephoto end, an interval between the first and second lens groups increases, an interval between the second and third lens groups increases, an interval between the third and fourth lens groups decreases, and an interval between the fourth and fifth lens groups decreases. The fourth and fifth lens groups are set to have a combined lateral magnification β45T to satisfy the following condition, when an object distance is infinite at a telephoto end: −0.041
Public/Granted literature
- US20130033759A1 ZOOM LENS AND INFORMATION DEVICE INCORPORATING THE SAME Public/Granted day:2013-02-07
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