Invention Grant
- Patent Title: Zoom lens
- Patent Title (中): 变焦镜头
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Application No.: US13269298Application Date: 2011-10-07
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Publication No.: US08599492B2Publication Date: 2013-12-03
- Inventor: Ryotaro Izumi
- Applicant: Ryotaro Izumi
- Applicant Address: JP Tokyo
- Assignee: Konica Minolta Opto, Inc.
- Current Assignee: Konica Minolta Opto, Inc.
- Current Assignee Address: JP Tokyo
- Agency: Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
- Priority: JP2010-229388 20101012
- Main IPC: G02B15/00
- IPC: G02B15/00 ; G02B15/15

Abstract:
There is provided a zoom lens which is suitable for a digital still camera and a video camera and includes a small number of lenses, especially a zoom lens which has an angle of view of 75° or more at the wide-angle end and a variable power ratio of about ×10. The zoom lens includes a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and, a fourth lens group with positive refractive power. The zoom lens varies power by changing an interval of each neighboring lens groups. The first lens group is composed of a negative lens and a positive lens. The third lens group is composed of an aperture stop, a cemented lens formed by a positive lens in a biconvex shape and a negative lens, and a positive lens.
Public/Granted literature
- US20120087018A1 ZOOM LENS Public/Granted day:2012-04-12
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