发明名称 Zoom lens system
摘要 A zoom lens system includes, in order from the object side, a first lens unit that remains fixed during zooming and which has a positive power, a second lens unit that has a zooming capability, that moves during zooming and that has a negative power, a third lens unit that has a capability of compensating for the position of the focal point, that moves during zooming and that has a negative power, and a fourth lens unit that has an imaging capability, that remains fixed during zooming and that has a positive power, said fourth lens unit comprising a first sub-unit that comprises, in order from the object side, a positive lens element, a positive lens element and a negative lens element and that has a positive overall power, and a second sub-unit that comprises, in order from the object side, a positive lens element, a negative lens element and a positive lens element and that has a positive overall power. The zoom lens system satisfies the specified conditions.
申请公布号 US5371630(A) 申请公布日期 1994.12.06
申请号 US19920917314 申请日期 1992.07.23
申请人 ASAHI KOGAKU KABUSHIKI KAISHA;ASAHI SEIMITSU KABUSHIKI KAISHA 发明人 ITO, TAKAYUKI;SUGANO, YASUYUKI
分类号 G02B15/17;(IPC1-7):G02B15/14 主分类号 G02B15/17
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