Patent ID: 6175453
Filing Date: 2001-01-16
Classification: G02B

Abstract:
A zoom lens including a plurality of lenses of different focal length, comprising:a first lens group having a positive focal length, the first lens group including at least three lenses of different curvature radius in which one lens has a negative focal length and two lenses have positive focal lengths;a second lens group having a negative focal length;a third lens group having a positive focal length;a fourth lens group having a positive focal length;a filter located behind and spaced from the fourth lens group, andan image plane located behind and spaced from the filter;wherein the first and third lens group are stationary relative to the image plane, and the second and fourth lens groups are movable relative to the image plane for forming a high resolution image on the image plane, wherein the lenses include lenses of different curvature radius grouping to form the different lens group of different focal length.