Patent ID: 6094313
Filing Date: 2000-07-25
Classification: G02B

Abstract:
A zoom lens system comprising:a first lens group having positive refracting power;a second lens group disposed nearer to an image side of said zoom lens system than said first lens group and having negative refracting power;a third lens group disposed nearer to the image side than said second lens group and having positive refracting power; anda fourth lens group disposed nearer to the image side than said third lens group and having negative refracting power,wherein for zooming from a wide-angle end to a telephoto end of a zooming area having a continuous zooming action, an intergroup space of each lens group is varied,at least one group of said four lens groups is moved to define an extended wide-angle point that is a discontinuous zooming point at a position where a focal length thereof becomes shorter than said wide-angle end of the zooming area, andat least one lens group of said four lens groups is moved to define an extended telephoto point that is a discontinuous zooming point at a position where a focal length thereof becomes longer than said telephoto end of the zooming area.