Patent attributes
In the zoom lens, the second lens group includes at least one surface that is an aspheric surface, and during changing magnification, the second lens group, the third lens group, and the fourth lens group are respectively capable of moving independently, with the position of the aperture moving along a convex trajectory on the optical axis from the image side to the object side during changing magnification. Through operation in this manner, the zoom lens of the invention is inexpensive and compact, and efficiently corrects various types of aberration. Thus, at a high magnification ratio of 5× or greater, the zoom lens of the invention affords a wide field exceeding approximately 78 degrees at the wide angle end, and affords a high performance compact zoom lens whose distortion is held to 3% or less.
