Patent attributes
An imaging lens includes a first lens; a second lens; a third lens; a fourth lens; a fifth lens; and a sixth lens, arranged in this order from an object side to an image plane side. The first lens has a surface thereof on the object side having a positive curvature radius. The second lens has surfaces on the object side and the image plane side having positive curvature radii. The third lens has a surface on the object side having a positive curvature radius and a surface on the image plane side having a negative curvature radius. The fifth lens is formed has an aspheric shape surface on the object side. The sixth lens has an aspheric shape surface on the image plane side. The first to fourth lenses have refractive power weaker than that of the fifth and sixth lenses.