Patent ID: 8014078

Claim:
A zoom lens consisting, in order from an object side thereof, of: a front side lens unit having a negative refracting power at a wide angle end; and a rear side lens unit having a positive refracting power at the wide angle end, wherein the front side lens unit consists of a first lens unit having a positive refracting power and a second lens unit having a negative refracting power, wherein the second lens unit consists, in order from the object side, of a first negative lens, a positive lens and a second negative lens, the rear side lens unit consists of a third lens unit having a positive refracting power and a rear lens unit on an image side of the third lens unit, during zooming from the wide angle end to the telephoto end, distances between the first lens unit, the second lens unit, the third lens unit and the rear lens unit respectively change, the distance between the first lens unit and the second lens unit is larger at the telephoto end than at the wide angle end, the distance between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide angle end, the distance between the third lens unit and the rear lens unit at the telephoto end is different from that at the wide angle end, the first lens unit is located closer to the object side at the telephoto end than at the wide angle end, the third lens unit is located closer to the object side at the telephoto end than at the wide angle end, the zoom lens satisfies the following condition: 0.05<(Σ D 12R )/ f t <0.19 (11) where ΣD 12R is the sum of thicknesses, on the optical axis, of the first lens unit, the second lens unit and the rear lens unit, the thickness of each lens unit referring to an actual distance from an object side surface of the lens located closest to the object side in that lens unit to an image side surface of the lens located closest to the image side in that lens unit, and f t is a focal length of the entire zoom lens system at the telephoto end, and an image side surface of the first negative lens in the second lens unit is a concave surface, an object side surface of the second negative lens in the second lens unit is a concave surface and an image side surface of the positive lens in the second lens unit is a convex surface.