| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact imaging lens at low cost, which materializes combining of low height with a wide angle, and is adaptable to brightness of F2.5 or brighter, and yet has well corrected aberrations.SOLUTION: The imaging lens comprises, in order from an object side to an image side; a first lens having a convex surface on the object side and positive refractive power; a second lens having a concave surface on the object side and negative refractive power; a third lens having convex surfaces on the object side and image side, of which at least one is an aspherical surface, and positive refractive power; a bi-aspherical fourth lens having a convex surface on the image side and positive refractive power; and a bi-aspherical fifth lens having a concave surface on the image side and negative refractive power. The imaging lens satisfies a conditional expression (1) below: 20<&ngr;d1-&ngr;d2<50 ...(1), where &ngr;d1 represents an Abbe number of the first lens for the d-ray, and &ngr;d2 represents an Abbe number of the second lens for the d-ray. |
