发明名称 Zoom lens, imaging apparatus, and information device
摘要 A zoom lens includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power, which are disposed in order from an object side to an image side and an aperture stop disposed between the second and third lens groups. When changing the magnification of the zoom lens from a short focal end to a long focal end, an interval between the first and second lens groups increases, an interval between the second and third lens groups decreases, and an interval between the third and fourth lens groups increases. The first and third lens groups are moved so as to be positioned at object side positions at the long focal end relative to positions at the short focal end. The third lens group has two positive lenses. Predetermined conditions of the positive lenses of the third lens group are satisfied.
申请公布号 US8493665(B2) 申请公布日期 2013.07.23
申请号 US201113050552 申请日期 2011.03.17
申请人 SUDOH YOSHIFUMI;RICOH COMPANY, LTD. 发明人 SUDOH YOSHIFUMI
分类号 G02B15/14 主分类号 G02B15/14
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