| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize a whole lens system and to obtain wide view angle by composing a 3rd group of a meniscus negative 31st lens, a stop and a bond lens of positive and negative lenses and satisfying a specified condition between the focal distance of the 31st lens and the focal distance of the wide angle end of the whole system. SOLUTION: This zoom lens has four lens groups of a 1st group L1 of positive refraction power, a 2nd group L2 of negative refraction power, a 3rd group L3 of positive refraction power and a 4th group L4 of positive refraction power successively from the side of an object. The 1st group L1 has at least two meniscus negative lenses turning a concave face toward the side of an image surface and three positive lenses and one of three positive lenses is composed of the bond lens of negative and positive lenses. The 3rd group L3 is composed of a meniscus negative 31st lens turning a concave face toward the image surface side, stop and the bond lens of positive and negative lenses. When the focal distance of the 31st lens is defined as f31 and the focal distance of the wide angle end of the entire system is defined as fw, the conditional expression of 6.5<|f31/fw|<25 is satisfied.
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