Patent ID: 6433939
Filing Date: 2002-08-13
Classification: G02B

Abstract:
A zoom lens system comprising a positive first lens group, a positive second lens group, and a negative third lens group, in this order from an object,wherein zooming is performed by moving said first through said third lens groups in the optical axis direction, and wherein said zoomlens system satisfies the following conditions: 0.62dT12âˆ’dW12)/fW<1.0 4T/f12T<6 5T/|f3G|<8 wherein dT12 designates the distance between said first lens group and said second lens group at the long focal length extremity; dW12 designates the distance between said first lens group and said second lens group at the short focal length extremity; fW designates the focal length of the entire zoom lens system at the short focal length extremity; fT designates the focal length of the entire zoom lens system at the long focal length extremity; f12T designates the combined focal length of said first lens group and said second lens group at the long focal length extremity; and f3G designates the focal length of said negative third lens group.