发明名称 Zoom lens system
摘要 A zoom lens system is disclosed which includes a first lens unit with negative optical power, a second lens element with positive optical power, and a third lens element with positive optical power, arranged in that order from an object side to an image side. The zoom lens system performs zooming by changing distances between the lens units. By configuring the first lens unit of a meniscus-shaped negative lens element whose convex surface faces the object side and a positive lens element, and by setting the refractive indices of the lens elements to appropriate values, a zoom lens system is realized, which has a small number of constituent lenses, which is compact and which has an excellent optical performance.
申请公布号 US6943962(B2) 申请公布日期 2005.09.13
申请号 US20040839145 申请日期 2004.05.05
申请人 CANON KABUSHIKI KAISHA 发明人 SEKITA MAKOTO
分类号 G02B15/20;G02B13/18;G02B15/177;(IPC1-7):G02B15/14 主分类号 G02B15/20
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