Patent ID: 8427759
Filing Date: 2013-04-23
Classification: G02B

Abstract:
1. An imaging lens comprising: a first lens having positive refractive power; a second lens having negative refractive power; and a third lens arranged in this order from an object side to an image side, wherein said first lens is formed in a shape so that both a curvature radius of a surface thereof on the object side and a curvature radius of a surface thereof on the image side are positive, said second lens is formed in a shape so that a curvature radius of a surface thereof on the object side is negative and a curvature radius of a surface thereof on the image side is positive, said third lens is formed in a shape so that both a curvature radius of a surface thereof on the object side and a curvature radius of a surface thereof on the image side are positive, and a whole lens system has a focal length f, said first lens has a focal length f1, said second lens has a focal length f2, and said third lens has a focal length f3 so that the following conditional expressions are satisfied: said first lens, said second lens, and said third lens are arranged so that a distance between the first lens and the second lens on an optical axis is dA and a distance between the second lens and the third lens on the optical axis is dB, and the following conditional expression is satisfied: