US Patent 10288839 Imaging lens

An imaging lens includes a first lens having positive refractive power; a second lens; a third lens; a fourth lens; a fifth lens; and a sixth lens, arranged in this order from an object side to an image plane side. The second lens is formed in a shape so that an entire surface thereof on the object side is convex. The fifth lens is formed in a shape so that a surface thereof on the object side is convex toward the object side near an optical axis thereof, and a surface thereof on the image plane side is convex toward the image plane side near the optical axis thereof. The fourth lens has a specific Abbe's number.