Patent ID: 6504656
Filing Date: 2003-01-07
Classification: G02B

Abstract:
A variable objective with finite transmission length L from the object plane 0 to the image plane 0â€², comprising:three axially displaceable lens groups, wherein, successively in the imaging direction, a first lens group has positive refractive power, a second lens group has negative refractive power and a third lens group has positive refractive power; said first lens group and third lens group, for purposes of changing magnification, being displaceable jointly while maintaining the same relative distance L2, wherein the distance L1+D1actual measured between the first lens group and the object plane 0 changes by the amount D1actual=0 . . . D1max, while the distance D2actual between the second lens group and the object plane 0 is reserved for the adjustment of the image sharpness with the position of the first lens group and third lens group being held constant.