发明名称 Zoom lens system
摘要 A zoom lens system includes a positive first lens group, a negative second lens group, a positive third lens group and a positive fourth lens group, in that order from the object side. Upon zooming from the short to long focal length extremities, the distance between the first and second lens groups increases, the distance between the second and third lens groups decreases, and the distance between the third and fourth lens groups changes. The second lens group includes a negative lens element having a concave surface on the image side, a negative lens element having a concave surface on the image side, and a plastic positive lens element having an aspherical surface on at least one side and having a convex surface on the object side, in that order from the object side.
申请公布号 US8699146(B2) 申请公布日期 2014.04.15
申请号 US201213435279 申请日期 2012.03.30
申请人 EGUCHI MASARU;HAYAKAWA KOICHIRO;HOYA CORPORATION 发明人 EGUCHI MASARU;HAYAKAWA KOICHIRO
分类号 G02B15/14;G02B3/02;G02B15/173 主分类号 G02B15/14
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