Patent ID: 6809882
Filing Date: 2004-10-26
Classification: G02B

Abstract:
A wide-angle zoom lens having only two lens groups, of negative and positive refractive power, respectively, in order from the object side, whereinzooming is performed by moving the first lens group and the second lens group along the optical axis, the first lens group is formed of, in sequential order from the object side, a negative meniscus lens element with its convex surface on the object side, two negative lens elements, and a positive lens element; the second lens group is formed of, in sequential order from the object side, two positive lens elements, a biconcave lens element, and two positive lens elements; and the following conditions are satisfied: 0.431/f2|<0.85 0.351N/f1<0.75 0.302W|<0.48 wheref1 is the focal length of the first lens group, f2 is the focal length of the second lens group, f1N is the composite focal length of the first three lens elements in the first lens group, in order from the object side, and m2W is the longitudinal magnification of the second lens group, at the wide-angle end.