Patent ID: 6934089
Filing Date: 2005-08-23
Classification: G02B,G06K

Abstract:
1. An objective lens system receiving light beams arriving generally telecentrically from an object, the objective lens system comprising: a first lens formed as a condensing lens, the first lens having a focal point and a focal length and receiving and guiding the light beams; an aperture stop having a center and positioned in the vicinity of the focal point of the first lens; a correcting second lens arranged between the first lens and the aperture stop and juxtaposed with the aperture stop wherein the second lens comprises a condensing lens with a spherical surface S a correcting third lens formed as a condensing lens and arranged beside the aperture stop opposite the second lens wherein the curvature center of the spherical surface of the second lens is at a distance shorter than 15% of the curvature radius of the spherical surface of the second lens from the center of the aperture stop and wherein the aperture stop is arranged at a distance shorter than 25% of the focal length of the first lens from the focal point of the first lens.