Patent ID: 6069751
Filing Date: 2000-05-30
Classification: G02B

Abstract:
A photographic lens comprising, in order from an object side to an image side:a first lens of positive refractive power having a meniscus shape convex toward the object side, said first lens being made from plastic material;a second lens of negative refractive power having a bi-concave shape, said second lens being made from plastic material;a third lens of positive refractive power having a bi-convex shape, said third lens being made from glass material; anda stop,wherein the following conditions are satisfied:0.8<f1/f<1.180.95<(td+sk)/f<1.121.45<N1<1.551.55<N2<1.65where f1 is a focal length of said first lens, f is a focal length of the entire photographic lens, td is a distance from a lens surface on the object side of said first lens to a lens surface on the image side of said third lens, sk is a back focal distance during focusing on an infinitely distant object, and N1 and N2 are refractive indices of materials of said first lens and said second lens, respectively.