Patent ID: 6728047
Filing Date: 2004-04-27
Classification: G02B

Abstract:
A compact photographing lens, wherein;an aperture stop is arranged at a position closest to an object, a first lens group, a second lens group, and a third lens group are arranged sequentially from the object side, said first lens group is formed by arranging, sequentially from the object side, a first lens having a positive refracting power and a second lens having a negative refracting power and bonded to the first lens, the second lens being formed from a meniscus lens with a concave surface facing the object side, said second lens group is formed from only a third lens as a meniscus lens which has at least one aspherical refracting surface and a concave surface facing the object side, said third lens group is formed from only a fourth lens as a meniscus lens which has at least one aspherical refracting surface and a convex surface facing the object side, and said photographing lens satisfies conditions (1) to (5): 0.801,2<1.00â€ƒâ€ƒ(1) âˆ’0.104<0.45â€ƒâ€ƒ(2) 0.22-2|<1.6â€ƒâ€ƒ(3) 2.93-1|<4.4â€ƒâ€ƒ(4) 2.01<2.9â€ƒâ€ƒ(5) wheref: focal length of entire system f1,2: combined focal length of first and second lenses f4: focal length of fourth lens r2-2: radius of curvature of image-side surface of second lens r3-1: radius of curvature of object-side surface of third lens d1: central thickness of first lens.