Patent ID: 8780458

Claim:
An imaging lens for forming a subject image on an imaging surface of a photoelectric conversion section of a solid state image sensor, the imaging lens comprising in order from an object side: a first lens having positive refractive power and a convex surface toward the object side; a second lens having negative refractive power and a concave surface toward an image side; a meniscus third lens having negative refractive power and a convex surface toward the object side; a fourth lens having positive refractive power and a convex surface toward the image side; and a fifth lens having negative refractive power and a concave surface toward the image side, wherein an image-side surface of the fifth lens has an aspherical shape and has a curvature changing point at a position other than an intersection point between the image-side surface and an optical axis, wherein the curvature changing point is a point on an aspherical surface and is a point at which a tangential plane of a crest of the aspherical surface is perpendicular to the optical axis; the first lens, the second lens, and the fifth lens are fixed with respect to the imaging surface; the third lens and the fourth lens are integrally moved in an optical axis direction to focus; and the following conditional expression is satisfied: 0.75 <f 34 /f< 1.30 (1) where: f34 is a combined focal length of the third lens and the fourth lens; and f is an overall focal length of the imaging lens.