Patent attributes
An imaging lens is provided and includes: in order from the object side, a first lens having a convex surface on the object side and having a positive power; an aperture diaphragm; a second lens having a concave surface on the object side and having a negative power; a third lens having a positive power; and a fourth lens having a convex surface on the object side near the optical axis, the fourth lens having a meniscus shape. The imaging lens satisfies conditional expressions:0.2<D2/f<0.4 (1)TL/f<1.3 (2)where f represents a focal distance of the imaging lens; D2 represents an air interval between the first lens and second lens along an optical axis of the imaging lens; and TL represents a distance (along the optical axis) from an object-side surface of the first lens to an image forming surface.
