发明名称 Zoom lens system and projector having the same
摘要 A zoom lens system discloses a zoom lens system which is small in size and exhibits favorable optical performance. The zoom lens system, according to the present invention includes, in order from the front to the rear: a first lens unit having negative optical power; a second lens unit having positive optical power; a third lens unit having positive optical power; a fourth lens unit having positive optical power; and a fifth lens unit having positive optical power. Of these five lens units, at least three lens units move at the time of zooming. Further, the fifth lens unit is provided with a positive lens element having a relatively high refractive index.
申请公布号 US2004012860(A1) 申请公布日期 2004.01.22
申请号 US20030620909 申请日期 2003.07.15
申请人 WADA KEN 发明人 WADA KEN
分类号 G02B15/20;G02B13/18;G02B15/177;(IPC1-7):G02B15/14 主分类号 G02B15/20
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