发明名称 Retrofocus lens system and image-taking device
摘要 Providing a retrofocus lens system and an image-taking device having small variation in aberrations upon focusing on a close object with a high imaging magnification. The retrofocus lens system includes, in order from an object, a first lens group G1 having negative refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. Upon focusing from infinity to a close object, the first lens group G1, the second lens group G2, and the third lens group G3 are moved to the object such that a distance between the first lens group G1 and the second lens group G2 increases, and a distance between the second lens group G2 and the third lens group G3 decreases.
申请公布号 US7656591(B2) 申请公布日期 2010.02.02
申请号 US20070674003 申请日期 2007.02.12
申请人 NIKON CORPORATION 发明人 YAMAMOTO HIROSHI
分类号 G02B13/04;G02B11/34 主分类号 G02B13/04
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