Patent ID: 6185049
Filing Date: 2001-02-06
Classification: G02B

Abstract:
A zoom lens system comprising, from the object side:a first lens unit having a positive optical power;a second lens unit having a positive optical power and provided at the image side of the first lens unit with a first variable air space between the first and second lens units, anda third lens unit having a negative optical power and provided at the image side of the second lens unit with a second variable air space between the second and third lens units,wherein a zooming operation is performed by varying the first and second air spaces, andwherein the zooming fulfills the following conditions:1.7<.beta.3W<2.0, and0.40<LBW/Y'<0.71where.beta.3W represents a lateral magnification of the third lens unit in a shortest focal length condition,LBW represents a lens back length in the shortest focal length condition (the lens back length is defined as a distance between a summit of a most image side surface of the zoom lens system and an image plane), andY' represents a maximum image height.