Imaging lens

Abstract

There is provided a compact and high-resolution imaging lens at a low cost. The imaging lens comprises in order from an object side to an image side, a first lens having positive refractive power and a convex surface facing the object side near an optical axis, a second lens having negative refractive power and a meniscus shape having the convex surface facing the object side near the optical axis, a third lens having the positive or the negative refractive power, a fourth lens having the convex surface facing the image side near the optical axis, a fifth lens having the positive refractive power, a sixth lens having the positive refractive power, and a seventh lens having the negative refractive power and a concave surface facing the image side near the optical axis, the image side surface of said seventh lens is formed as an aspheric surface which changes to the convex surface at a peripheral area, the object-side surface of said fifth lens has the convex surface facing the object side near the optical axis, all lenses are single lenses arranged with an interval between lenses adjacent to each other, and below conditional expressions (1), (2) and (3) are satisfied: 1.50<Nd1<1.60  (1) −8.0f2/f<−2.0  (2) 0.3<t2/t3<3.3  (3) where Nd1: refractive index at d-ray of the first lens, f: focal length of the overall optical system, f2: focal length of the second lens, t2: distance along the optical axis from the image-side surface of the second lens to the object-side surface of the third lens, and t3: distance along the optical axis from the image-side surface of the third lens to the object-side surface of the fourth lens.

Dependencies are inferred from the claim text.