Patent ID: 7636205

Claim:
A wide-angle imaging lens comprising, in order from an object: a first lens having a negative refractive power, the first lens being a double concave lens, or a negative meniscus shape with a concave face directed to the object, or a negative meniscus shape with a convex face directed to the object; a second lens having a positive refractive power with a convex face directed to the object; an aperture diaphragm; a third lens having a positive refractive power with a convex face directed to an image; and a fourth lens having a positive refractive power with a convex face directed to the object, wherein the following conditional expressions are satisfied, N2≧1.7 (1) N3≧1.7 (2) N4≧1.7 (3) when N 2 : a refractive index of the second lens at the d-line N 3 : a refractive index of the third lens at the d-line N 4 : a refractive index of the fourth lens at the d-line.