Patent ID: 7446944
Filing Date: 2008-11-04
Classification: G02B

Abstract:
1. An objective lens having a housing, an iris diaphragm, and a plurality of lens groups, wherein, for focusing said objective lens while minimizing a variation of an image angle, at least two lens groups are adapted to be moved relative to said housing, one of said two lens groups being arranged in front of said iris diaphragm, and the other of said two lens groups being arranged at least partially behind said iris diaphragm; wherein in said objective lens the condition: is fulfilled with a maximum deviation of less than 10%, wherein f′(e) is the focal length of said objective lens when a distance e to an object is set; f′(∞) is the focal length of said objective lens when a distance ∞ to an object is set; β(e) is the imaging scale of said objective lenses when a distance ∞ to an object is set; and APF is the distance between the exit pupil and the focal point.