Patent ID: 8000038

Claim:
An image pickup lens comprising: a lens group arranged at a closest position to an object side in the image pickup lens; and an optical member being a parallel flat plate, arranged at an image side of the lens group with a predetermined distance, wherein the lens group comprises: a first lens substrate being a parallel flat plate; a first lens with an Abbe number v 1 and a positive refractive power, formed on an object side surface of the first lens substrate, an object side surface of the first lens being a convex surface facing the object side; and a second lens with an Abbe number v 2 and a negative refractive power, formed on an image side of the first lens substrate, the image side surface of the second lens being a concave surface facing the image side, a difference of the Abbe numbers v 1 and v 2 satisfies the following expression (1), and the optical member satisfies the following expression(2): 10 < ( v ⁢ ⁢ 1 - v ⁢ ⁢ 2 ) < 70 ( 1 ) 0.13 > l 2 - l 1 f , ( 2 ) where 1 1 is an optical path length of an axial ray from the second lens to an image plane, 1 2 is an optical path length of a principal ray at a maximum image height from the second lens to the image plane, and f is a focal length of a total lens system of the image pickup lens.