Patent ID: 9134509
Filing Date: 2015-09-15
Classification: G02B

Abstract:
1. An imaging lens comprising: a first lens having negative refractive power; a stop; a second lens having positive refractive power; a third lens having negative refractive power; and a fourth lens having positive 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 is concave and a surface thereof on the image plane side is convex, said second 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 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 fourth lens is formed in a shape so that a surface thereof on the object side is convex, and said first lens has a focal length f