Patent ID: 6771431
Filing Date: 2004-08-03
Classification: G02B

Abstract:
A zoom lens comprising, in order from an object side to an image side:a first lens unit having a negative optical power, the first lens unit including a meniscus negative lens element having a concave lens surface on the image side, and a meniscus positive lens element having a convex lens surface on the object side; a second lens unit having a positive optical power, the second lens unit consisting of, in the order from the object side to the image side, a lens element having a convex lens surface, or a cemented lens having a convex lens surface, on the object side of an aperture stop, and one or two lens elements; and a third lens unit having a positive optical power, wherein a distance between the first lens unit and the second lens unit upon the telephoto end is shorter than that on the wide angle end and a distance between the second lens unit and the third lens unit upon the telephoto end is longer than that upon the wide angle end, and said zoom lens satisfies the following condition, 0.6D12Wâˆ’D12T)/(D23Tâˆ’D23W)<2.0, where D12W is the distance between the first lens unit and the second lens unit upon the wide angle end, D23W is the distance between the second lens unit and the third lens unit upon the wide angle end, D12T is the distance between the first lens unit and the second lens unit upon the telephoto end, and D23T is the distance between the second lens unit and the third lens unit upon the telephoto end.