Patent ID: 6751030
Filing Date: 2004-06-15
Classification: G02B

Abstract:
A zoom lens comprising in order from an object side:a first lens unit which has a positive optical power; a second lens unit which has a negative optical power; a third lens unit which has a positive optical power; and a fourth lens unit which has a positive optical power, wherein, during zooming from a wide angle end to a telephoto end, a spacing between the first lens unit and the second lens unit is increased, a spacing between the second lens unit and the third lens unit is decreased, a spacing between the third lens unit and the fourth lens unit is increased, and an aperture stop moves together with the third lens unit, and the following condition is satisfied: âˆ’1.0Cwâˆ’Ct)/f3where Cw represents a spacing between the third lens unit and the fourth lens unit on an optical axis at the wide angle end, Ct represents a spacing between the third lens unit and the fourth lens unit on the optical axis at the telephoto end, and f3 represents a focal length of the third lens unit.