发明名称 Zoom lens
摘要 A zoom lens is disclosed comprising, from front to rear, a first lens unit of negative refractive power, a second lens unit of positive refractive power, a third lens unit of negative refractive power and a fourth lens unit of positive refractive power, zooming from a wide-angle end to a telephoto end being performed by moving at least the first, second and fourth lens units in such a way that an air separation between the first and second lens units decreases, an air separation between the second and third lens units increases and an air separation between the third and fourth lens units decreases, wherein the form and the construction and arrangement of the members of the lens units and, if an aspheric surface is in use, its shape, are appropriately determined.
申请公布号 US5576890(A) 申请公布日期 1996.11.19
申请号 US19950440980 申请日期 1995.05.15
申请人 CANON KABUSHIKI KAISHA 发明人 TANAKA, TSUNEFUMI;OGAWA, HIDEKI;ENDO, HIROSHI
分类号 G02B15/177;(IPC1-7):G02B15/14 主分类号 G02B15/177
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