| 摘要 |
PROBLEM TO BE SOLVED: To provide a wide angle imaging lens for achieving an excellent optical performance while attaining further cost reduction, miniaturization, and lightweight. SOLUTION: The wide angle imaging lens includes, in the order starting from the object side, a negative meniscus lens L1 having a convex surface on the object side, a negative lens L2, having concave surfaces on its both sides and constituting at least one of both surfaces by an aspherical surface, a positive lens L3 having a convex surface on the object side and constituting at least one of both the surfaces by an aspherical surface, and a lens L4, having a convex surface on an image side and constituting at least one of both the surfaces by an aspherical surface. Furthermore, the Abbe number for the negative meniscus lens L1, with respect to d line is set equal to, or larger than Abbe number of the positive lens L3, with respect to the d line, Abbe numbers of the negative lens L2 and the lens L4 with respect to the d line are set to be larger than the Abbe number of the positive lens L3 with respect to the d line, and an aperture diaphragm 5 is arranged between the positive lens L3 and the lens L4. COPYRIGHT: (C)2011,JPO&INPIT
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