Patent ID: 9025035
Filing Date: 2015-05-05
Classification: G02B,H04N

Abstract:
1. A zoom lens system for forming an optical image of an object on a light receiving surface with a diagonal length of 2Ymax of an image sensing device for converting the optical image into an electrical signal, the zoom lens system being composed of, from an object side, a first group having a positive optical power, a second group having a negative optical power, a third group having a negative optical power, an aperture stop, and a plurality of groups having a positive optical power as a whole, the zoom lens system achieving zooming by varying distances between the groups, wherein the zoom lens system achieves focusing by moving the third group, and wherein the zoom lens system fulfills conditional formulae (1) and (2) below: where, when the plurality of groups located to an image side of the aperture stop are referred to as rear groups, wherein the rear groups are composed of, from the object side, a fourth group having a positive optical power and a fifth group having a positive optical power.