Patent ID: 7242533
Filing Date: 2007-07-10
Classification: G02B

Abstract:
1. A two-unit zoom lens system comprising, in order from an object side to an image side: a first lens unit having a negative refractive power; and a second lens unit having a positive refractive power, wherein during change of magnification from a wide-angle end to a telephoto end, the first lens unit and the second lens unit are moved so as to reduce a space between the first lens unit and the second lens unit, the first lens unit comprises, in order from the object side, a negative sub-unit G the second lens unit comprises, in order from the object side, a first positive lens L the two-unit zoom lens system further comprising: an aperture stop disposed in an air space which comes into contact with the first positive lens L the following conditions (A), (B) being satisfied: in which r 21a denotes a paraxial radius of curvature of an object-side surface of the first positive lens L 21 , r 21b denotes a paraxial radius of curvature of an image-side surface of the first positive lens L 21 , r 22a denotes a paraxial radius of curvature of an object-side surface of the second negative lens L 22 , and r 22b denotes a paraxial radius of curvature of an image-side surface of the second negative lens L 22 .