发明名称 Zoom lens system and camera having the same
摘要 A zoom lens system, in that order from an object side to an image side, includes first to fourth lens units respectively having positive, negative, positive, and positive optical powers. The second and fourth lens units move along an optical axis during zooming. In the zoom lens system, the third lens unit includes a first lens subunit having a negative optical power, and a second lens subunit having a positive optical power, in that order from the object side to the image side. The first lens subunit has no more than a positive lens element and a negative lens element. The second lens subunit has no more than a positive lens element and a negative lens element. Accordingly, the arrangements of the third lens unit and other lens units are properly set.
申请公布号 US7595936(B2) 申请公布日期 2009.09.29
申请号 US20080108734 申请日期 2008.04.24
申请人 CANON KABUSHIKI KAISHA 发明人 HOSHI KOJI
分类号 G02B15/14 主分类号 G02B15/14
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