Patent ID: 9638896
Date: 2017-05-02
CPC Classifications: G02B

Claim:
1. An imaging lens with a fixed focal length which forms an image of an object on a solid-state image sensor, in which lenses are arranged in order from an object side to an image side of the imaging lens, comprising: a first lens group with positive refractive power, the first lens group including, in order from the object side: a first lens with positive refractive power having a convex object-side surface, and a second lens; a second lens group with positive refractive power, the second lens group including, in order from the object side: a third lens, and a fourth lens, each having at least one aspheric surface; and a third lens group with negative refractive power, the third lens group including, in order from the object side: a fifth lens, a sixth lens that is a double-sided aspheric lens, and a seventh lens having a concave image-side surface near an optical axis of the imaging lens, wherein the lenses are not joined to each other, the image-side surface of the seventh lens has an aspheric surface whose shape changes from concave to convex as a distance from the optical axis increases, and an F-number is less than 1.8.