发明名称 Zoom lens and image pickup apparatus
摘要 A zoom lens of a novel configuration suitable for a collapsible lens barrel is disclosed. More specifically, here is disclosed a zoom lens, comprising four lens units which are, in the order from an object side toward an image side, positive, negative, positive and positive in optical power, and performing zooming by varying distances between each lens units. In this zoom lens, the fourth lens unit has a positive lens element and a negative lens element, and satisfies the following conditional expression: 1<nun-nup<30 where nun is the Abbe number of the negative lens element of the fourth lens unit, and nup is the Abbe number of the positive lens element of the fourth lens unit.
申请公布号 US2003063395(A1) 申请公布日期 2003.04.03
申请号 US20020209683 申请日期 2002.07.31
申请人 SARUWATARI HIROSHI 发明人 SARUWATARI HIROSHI
分类号 G02B15/20;G02B15/173;(IPC1-7):G02B15/14;G02B9/34 主分类号 G02B15/20
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