SUBMINIATURE OPTICAL SYSTEM

摘要

A subminiature optical system is provided to improve degradation of definition of a peripheral unit according to the serious astigmatism increment at an image outer and improve resolution by reducing TV distortion. A first lens element(L1) has a convex shape. A second lens element(L2) in which the side of an object is welded to the upper surface of the first lens element is formed. A third lens element(L3) in which the side of the object is welded to the upper surface of the second lens element is formed. The side of the object of the first lens element and the upper surface of the third lens element are made of aspherics. The upper surface of the third lens element is bulging from a central part to upper and has positive refractive power. The upper surface of the third lens element is concave from a peripheral unit to upper and has negative refractive power. The upper surface of the third lens element forms curve change point within the lens effective particle diameter.