Patent ID: 8941930
Filing Date: 2015-01-27
Classification: G02B

Abstract:
1. An imaging lens comprising: a first lens having positive refractive power; a second lens having positive refractive power; and a third lens having positive refractive power, arranged in an 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 is convex, said second lens is formed in a shape so that a surface thereof on the object side is concave and a surface thereof on the image plane side is convex, said third lens is formed in a shape so that a surface thereof on the object side is convex and a surface thereof on the image plane side is concave, said third lens is formed in the shape so that the surface thereof on the object side and the surface thereof on the image plane side are respectively formed as aspheric surfaces having inflexion points, said first lens has a focal length f where f is a focal length of a whole lens system, and said first lens has the surface on the image plane side situated away from the surface of the second lens on the object side by a distance D