Patent ID: 7848028

Claim:
A variable focal length lens system, comprising: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a negative refracting power; a fifth lens group having a negative refracting power; and a sixth lens group having a positive refracting power; said first to sixth lens groups being disposed in order from an object side; variation of a lens position state from a wide angle end state to a telephoto end state causing increase of the distance between said first and second lens groups, decrease of the distance between said second and third lens groups, increase of the distance between said third and fourth lens groups, decrease of the distance between said fourth and fifth lens groups, and variation of the distance between said fifth and sixth lens groups while said first lens group first moves to an image side once and then moves to the object side and said fourth lens group is fixed in the direction of the optical axis and besides said third and fifth lens groups move integrally with each other to the object side; said second lens group being positioned on the image side in the telephoto end state in comparison with the position thereof in the wide angle end state; said variable focal length lens system further including an aperture stop disposed in the proximity of said third lens group; and said sixth lens group being moved in the direction of the optical axis in response to variation of the position of an image pickup object.