Patent ID: 7542212
Filing Date: 2009-06-02
Classification: G02B

Abstract:
1. A zoom lens comprising, in order and from the side of an object, a first lens group having a positive refractive power and fixed in position, a second lens group having a negative refractive power and movable in position for providing mainly zooming, a third lens group having a positive refractive power and fixed in position, a fourth lens group having a positive refractive power and movable in position for performing a focal position correction due to the zooming and for focusing, and a fifth lens group including a single lens fixed in position, wherein each of the lens groups from the third lens group to the fifth lens group has at least one aspheric surface, and conditional equations (1) and (2) below are satisfied, where f4 is a focal length of the fourth lens group, f5 is a focal length of the fifth lens group, and β5 is a transverse magnification of the fifth lens group.