Patent ID: 7724448

Claim:
A zoom lens comprising, in order from an object side thereof: a first lens unit having a positive refracting power; a second lens unit having a negative refracting power; a third lens unit having a positive refracting power; and a fourth lens unit having a refracting power, wherein the zoom lens further comprises an aperture stop disposed closer to the image side than the second lens unit and closer to the object side than a lens surface closest to the image side in the third lens unit, during zooming from a wide angle end to a telephoto end in a state in which the zoom lens is focused at the farthest distance, a distance between the first lens unit and the second lens unit is larger at the telephoto end than at the wide angle end, a distance between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide angle end, a distance between the third lens unit and the fourth lens unit changes, the first lens unit, the third lens unit and the aperture stop move in such a way that they are located closer to the object side at the telephoto end than at the wide angle end, when a lens component is defined as a lens member whose surfaces that are in contact with air on an optical axis include only two surfaces, one being an incidence side surface and the other being an exit side surface, the first lens unit comprises one lens component, and the total number of lens components included in the first lens unit is one, the third lens unit comprises a positive lens and a negative lens, and the zoom lens satisfies the following conditions: 0.8 <ΔG 1 /ΔG 3 <1.6 0.15<φ3/φ<0.35 8.0< f t /f w <25.0 where, ΔG 1 is an amount of displacement, on the optical axis, of the position of the first lens unit at the telephoto end with respect to the position thereof at the wide angle end, wherein displacements toward the object side at the telephoto end are represented by positive values, ΔG 3 is an amount of displacement, on the optical axis, of the position of the third lens unit at the telephoto end with respect to the position thereof at the wide angle end, wherein displacements toward the object side at the telephoto end are represented by positive values, φ3 is a lens size in the third lens unit represented by the maximum value of a length from one edge to another of the lens measured along a straight line containing a point through which the optical axis passes and perpendicular to the optical axis, φ4 is a lens size in the fourth lens unit represented by the maximum value of a length from one edge to another of the lens measured along a straight line containing a point through which the optical axis passes and perpendicular to the optical axis, f w is a focal length of the entire zoom lens system at the wide angle end, and f t is a focal length of the entire zoom lens system at the telephoto end.