Patent ID: 6608970
Filing Date: 2003-08-19
Classification: G03B

Abstract:
A zoom optical system comprising a lens system, said lens system consisting of, in order from an object side:a first lens unit having a positive refracting power; and a second lens unit having a negative refracting power, in variable magnification change from a wide-angle end position through a telephoto end position, each of said first lens unit and said second lens unit being moved toward the object side in such a manner that a space between said first lens unit and said second lens unit decreases, wherein said first lens unit consists of, in order from the object side, a first lens component having a positive refracting power, a second lens component having a negative refracting power, and a third lens component having a positive refracting power, said third lens component consisting of one cemented-lens component, and wherein the following condition is satisfied: fT/fW>3 where fT is a focal length of the entire zoom optical system in the telephoto end position, and fW is a focal length of the entire zoom optical system in the wide-angle end position.