Invention Grant
US08873161B2 Zoom lens, camera apparatus, information device and mobile information terminal apparatus
有权
变焦镜头,相机装置,信息装置和移动信息终端装置
- Patent Title: Zoom lens, camera apparatus, information device and mobile information terminal apparatus
- Patent Title (中): 变焦镜头,相机装置,信息装置和移动信息终端装置
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Application No.: US12968993Application Date: 2010-12-15
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Publication No.: US08873161B2Publication Date: 2014-10-28
- Inventor: Takahiro Nakayama
- Applicant: Takahiro Nakayama
- 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: JP2009-284551 20091215; JP2010-058463 20100315
- Main IPC: G02B15/16
- IPC: G02B15/16 ; G02B15/173 ; G02B27/00

Abstract:
A zoom lens includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, an aperture stop, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power, which are disposed in order from an object side. The first lens group has a negative lens and a positive lens having a convex surface at an object side, which are disposed in order from the object side. An interval between the first lens group and the second lens group is increased and an interval between the second lens group and the third lens group is decreased when changing a magnification of the zoom lens from a wide angle end to a telephoto end. The first lens group and the third lens group are moved from positions at the wide angle end toward positions, which are at object sides thereof, at the telephoto end, respectively. Parameters are set so as to successfully correct chromatic aberration while achieving compact size, wide half field angle at the wide angle end, good performance, and a high magnification ratio.
Public/Granted literature
- US20110141578A1 ZOOM LENS, CAMERA APPARATUS, INFORMATION DEVICE AND MOBILE INFORMATION TERMINAL APPARATUS Public/Granted day:2011-06-16
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