Patent ID: 9146382
Filing Date: 2015-09-29
Classification: G02B

Abstract:
1. An imaging lens comprising: a first lens having positive refractive power; a second lens having negative refractive power; a third lens having negative refractive power; a fourth lens; and a fifth lens having negative refractive power, arranged in this order from an object side to an image plane side, wherein said first lens is formed in a shape so that a surface thereof on the object side has a positive curvature radius, said third lens is formed in a shape so that a surface thereof on the image plane side has a positive curvature radius, said fifth lens is formed in a shape so that a surface thereof on the object side has a negative curvature radius, and a surface thereof on the image plane side has a positive curvature radius, and said first lens has an Abbe's number νd1, said second lens has an Abbe's number νd2, said third lens has an Abbe's number νd3, 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: