| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens achieving not only excellent optical performance but also reduction in size and wide angle property. SOLUTION: A negative first lens group G1, a positive second lens group G2, an aperture, and a positive third lens group G3 are arranged in this order from the object side. The first lens group G1 has at least two lenses. The second lens L12 of the first lens group G1 from the object side has a convex face directing the object side, and all of the lenses composing the first lens group G1 are negative. The second lens group G2 has at least one lens L21 of biconvex shape. The third lens group G3 has at least a negative lens L33 of meniscus shape and a positive lens L32 in this order from the closest side to the image. Abbe's numberν<SB>2</SB>of a lens L21 of the second lens group G2 to a d line satisfies the conditional expression (1),ν<SB>2</SB><43. COPYRIGHT: (C)2009,JPO&INPIT
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