发明名称 Zoom lens and information device
摘要 A zoom lens includes, in order from an object side, a first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, a fourth lens group having a positive refracting power, and the first lens group being moved to the object side during changing a magnification from a wide angle end to a telephoto end, and the fourth lens group comprises one positive lens, both surfaces of the positive lens are an aspheric surface, respectively, and total displacement of the first lens group during changing the magnification from the wide angle end to the telephoto end, X1 and an focal length of an entire system at the telephoto end, fT satisfy the following condition: (1) 0.30 < X1 / fT < 0.85.
申请公布号 EP1717626(A1) 申请公布日期 2006.11.02
申请号 EP20060252313 申请日期 2006.04.28
申请人 RICOH COMPANY, LTD. 发明人 OHASHI, KAZUYASU
分类号 G02B15/173;H04N1/00 主分类号 G02B15/173
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