发明名称 Zoom lens
摘要 A zoom lens 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 positive refractive power and a fourth lens unit of negative refractive power, totaling four lens units, wherein, when zooming from the wide-angle end to the telephoto end, the lens units move axially in such relation that the air separation between the first lens unit and the second lens unit increases, the air separation between the second lens unit and the third lens unit increases and the air separation between the third lens unit and the fourth lens unit decreases.
申请公布号 US5587840(A) 申请公布日期 1996.12.24
申请号 US19950505911 申请日期 1995.07.24
申请人 CANON KABUSHIKI KAISHA 发明人 ITOH, YOSHINORI
分类号 G02B15/177;(IPC1-7):G02B15/14 主分类号 G02B15/177
代理机构 代理人
主权项
地址