Invention Grant
- Patent Title: Zoom lens, imaging device and information device
- Patent Title (中): 变焦镜头,成像设备和信息设备
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Application No.: US13046087Application Date: 2011-03-11
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Publication No.: US08405917B2Publication Date: 2013-03-26
- Inventor: Yoshifumi Sudoh
- Applicant: Yoshifumi Sudoh
- 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: JP2010-055377 20100312
- Main IPC: G02B15/14
- IPC: G02B15/14

Abstract:
A zoom lens includes, in order from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, the second lens group including, in order from the object side, a first negative lens and a cemented lens including a second negative lens having a convex shape on the object side and a positive lens, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and an aperture stop arranged between the second lens group and the third lens group, wherein when changing a magnification from a short focal end to a telephoto end, an interval between the first lens group and the second lens group is increased, an interval between the second lens group and the third lens group is decreased, an interval between the third lens group and the fourth lens group is increased, and the first lens group and the third lens group are moved to be located closer to the object side at the long focal end than the short focal end.
Public/Granted literature
- US20110222169A1 ZOOM LENS, IMAGING DEVICE AND INFORMATION DEVICE Public/Granted day:2011-09-15
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