Patent ID: 7450316
Filing Date: 2008-11-11
Classification: G02B

Abstract:
1. A zoom lens system comprising, in order from an object side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; and a fourth lens unit having a positive refractive power, during zooming from a wide-angle end to a telephoto end, at least the first lens unit and the third lens unit being moved toward the object side so as to increase a space between the first lens unit and the second lens unit and decrease a space between the second lens unit and the third lens unit, the following conditions being satisfied: in which f w is a focal length of the zoom lens system in the wide-angle end, f I is a maximum image height of a formed image, f f f M M M M