Patent ID: 6940663
Filing Date: 2005-09-06
Classification: G02B

Abstract:
1. A zoom lens system comprising in order from an object side to an image side: a first lens unit having a positive optical power; a second lens unit having a positive optical power, the second lens unit having, in order from the object side to the image side, a first lens subunit having one of a positive optical power and a negative optical power, and a second lens subunit having a positive optical power; and a third lens unit having a negative optical power, wherein a spacing between the first lens unit and the second lens unit and a spacing between the second lens unit and the third lens unit are changed during zooming, and at least the first lens unit and the third lens unit are moved toward the object side, and in the second lens unit, the second lens subunit is moved toward the object side such that the spacing between the first lens subunit and the second lens subunit is changed during focusing on an object at a short distance from an object at infinity in at least one zoom position.