Patent ID: 7755848
Filing Date: 2010-07-13
Classification: G02B

Abstract:
1. A zoom lens system comprising in order from an object side thereof: a first lens unit having a positive refracting power; a second lens unit having a negative refracting power; a rear lens group having a positive refracting power which includes a third lens unit having a positive refracting power; and an aperture stop which is disposed between the second lens unit and the third lens unit, wherein at a time of zooming from a wide angle end to a telephoto end, when focused on an object at a longest distance, each of the first lens unit, the second lens unit, and the third lens unit moves such that a distance between the first lens unit and the second lens unit is increased and a distance between the second lens unit and the third lens unit is decreased, and the aperture stop moves such that a distance of the aperture stop from the second lens unit is decreased, and the second lens unit comprises in order from the object side, a first negative lens L the total number of lenses in the second lens unit is three, and satisfies the following conditional expressions where, f f f wherein a material of the positive lens in the second lens unit satisfies the following conditional expressions where, n ν