Patent ID: 6515803
Filing Date: 2003-02-04
Classification: G02B

Abstract:
A zoom lens system, comprising, sequentially from an enlargement side thereof to a reduction side thereof:a first lens unit having a negative optical power; a second lens unit having a positive optical power; a third lens unit having a positive optical power; a fourth lens unit having a negative optical power; and a fifth lens unit having a positive optical power, wherein, during a zoom operation from a longest focal length condition to a shortest focal length condition the following conditions are satisfied: âˆ’2.01/fW1.1â€ƒâ€ƒ(1) 1.52/fW<2.7â€ƒâ€ƒ(2) 3.53/fW<20â€ƒâ€ƒ(3) 0.65/fW<1.2â€ƒâ€ƒ(4) where,fW represents a focal length of the zoom lens system at the shortest focal length condition; f1 represents a focal length of said first lens unit; f2 represents a focal length of said second lens unit; f3 represents a focal length of said third lens unit; and f5 represents a focal length of said fifth lens unit.