Patent ID: 7576924
Filing Date: 2009-08-18
Classification: G02B

Abstract:
1. A two-unit zoom lens system comprising in order from an object side thereof: a first lens unit having a negative refracting power; a second lens unit having a positive refracting power; and an aperture stop which is disposed between the first lens unit and the second lens unit, and which moves integrally with the second lens unit, wherein at a time of zooming from a wide angle end to a telephoto end, a distance between the first lens unit and the second lens unit is narrowed, and at the time of zooming from the wide angle end to the telephoto end, the first lens unit, after moving toward an image side, moves toward an object side, and at the time of zooming from the wide angle end to the telephoto end, the second lens unit moves toward the object side, and the second lens unit comprises in order from the object side thereof, a front sub-unit having a positive refracting power and a rear sub-unit having a negative refracting power, with the longest air space in the second lens unit between the front sub-unit and the rear sub-unit, and there is no other lens unit in the second lens unit, and the two-unit zoom lens system satisfies the following conditional expressions where, f f d