| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging lens of small size and high performance in which an internal space for arranging a shutter mechanism can be sufficiently assured while maintaining high aberration performance corresponding to high pixels by using a lens material advantageous to productivity and cost reduction. SOLUTION: The imaging lens is provided with a first lens which has positive refractive power, a second lens which turns a concave surface toward an object side and has negative refractive power and a third lens which has a positive meniscus shape turning a convex face toward the object side near an optical axis, in this order from the object side. Further following conditional expressions: (1) 0.7<f1/f<1.3, (2) 0.25<D2/f<0.50, (3) 55<ν123, (4) ¾ν123-ν2¾<5 are satisfied, wherein (f) denotes focal length of a whole system, (f1) denotes focal length of the first lens G1, D2 denotes an interval between the first lens G1 and the second lens G2 on the optical axis Z1, (ν123) denotes an average of Abbe's numbers of the first lens, the second lens and the third lens and (ν2) denotes Abbe's number of the second lens. COPYRIGHT: (C)2008,JPO&INPIT
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