| 摘要 |
This invention is related to 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, the 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, the 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, the 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 the photographing lens satisfies conditions (1) to (5): 0.80<f/f1,2<1.00 (1) -0.10<f/f4<0.45 (2) 0.2<|f/r2-2|<1.6 (3) 2.9<|f/r3-1|<4.4 (4) 2.0<f/d1<2.9 (5) where f: 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
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