Patent ID: 9383547
Filing Date: 2016-07-05
CPC Classification: G02B,H04N

Claim Text:
1. An imaging lens, comprising in an ordered way from an object side: a first lens having positive (+) refractive power; a second lens having negative (−) refractive power; a third lens having negative (−) refractive power; and a fourth lens having negative (−) refractive power; wherein the imaging lens meets a conditional expression of −0.5<f/f3<0 and −0.5<f/f4<0, where f is an entire focus distance of the imaging lens, f3: is a focus distance of the third lens, and f4 is a focus distance of the fourth lens; wherein the imaging lens meets conditional expressions of: a) 10<[(V1+V3)/2−V2]<20 and V3<30, and b) 10<[(V1+V4)/2−V2]<20 and V4<30; where V1, V2, V3, and V4 are Abbe's numbers of the first to fourth lenses, respectively; and wherein the second lens is concavely formed at an image side surface, and takes a meniscus form.