| 摘要 |
PURPOSE:To obtain a high-magnification, wide-aperture microscope objective having various aberrations compensated excellently by allowing the lens system consisting of a positive single lens, positive-negative cemented lens, two groups of cemented lenses, positive single lens, and negative-positive cemented lens to meet prescribed requirements. CONSTITUTION:The lens system of 6-group constitution which consists of a positive single lens, negative-positive cemented lens, two groups of cemented lenses including a positive lens, positive single lens, and negative-positive cemented lens from an object side meets equirements as shown by inequalities (1)-(4), where r1 is the radius of curvature of the object-side surface of the 1st group and n1 is the refractive index of the 1st group; nu2p-nu6p, and nu6p are Abbe numbers of the positive lenses in the 2nd-the 4th groups and the 6th group, and nu6n is the Abbe number of the negative lens of the 6th group; and (f) is the total focal length of the system and f6 is the focal length of the 6th group. Consequently, the microscope object has 100 high magnification, >=0.9 numerical aperture, and long operation distance, and its various aberrations are compensated excellently. |
