Patent ID: 7675692

Claim:
A pickup lens, comprising: an aperture diaphragm S 1 , a first lens L 1 , a second lens L 2 , and a third lens L 3 , and being configured by arranging in order, from an object side to an image side, said aperture diaphragm S 1 , said first lens L 1 , said second lens L 2 , and said third lens L 3 , and wherein said first lens L 1 is a lens having positive refractive power, with convex surfaces directed toward the object side and toward the image side; said second lens L 2 is a lens having negative refractive power, in a meniscus shape with the convex surface directed toward the image side; said third lens L 3 is a lens having negative refractive power, in a meniscus shape with a convex surface directed toward the object side; both surfaces of said first lens L 1 are aspherical, both surfaces of said second lens L 2 are aspherical, and both surfaces of said third lens L 3 are aspherical; and the following conditions are satisfied: 0.01<| r 2 /r 3 |<0.05 (1-1) 0.05 <D/f≦ 0.1 (1-2) 0.6< L/ 2 Y< 0.9 (1-3) 0.5< f 1 /f< 0.7 (1-4) where, f: combined focal length of said pickup lens r 2 : radius of curvature of the object-side surface of said first lens L 1 in the vicinity of the optical axis r 3 : radius of curvature of the image-side surface of said first lens L 1 in the vicinity of the optical axis D: interval between said second lens L 2 and said third lens L 3 along the optical axis L: distance in air along the optical axis from the object-side surface of said first lens L 1 to the image plane (optical length) 2Y: length of a diagonal line in an effective picture area of a solid-state image pickup element installed at an image plane of said pickup lens f 1 : focal length of said first lens L 1 .