Abstract: A microscope objective adjustable for different thicknesses of cover-glass includes a second lens (L2 and L3) movable between a first lens (L1) and a third lens (L4) and a fourth lens (L5) movable with the second lens, but in an opposite direction. A ring that accomplishes movements of the second and fourth lenses also resets the focus of the objective. All movements are linear and are arranged to maintain the correction of image error while the objective is adjustable over a wide range of cover-glass thicknesses from 0 to 2 mm.

Abstract: The invention contemplates use of a bayonet mount for microscope objectives, instead of the customary threaded mounting of such objectives. The bayonet mount is characterized by the objective (1) having a centering cone (3) which engages and precisely centers in a conical opening (10) in the turret of the microscope. The structure not only permits rapid changing of the objective, but the thus-mounted objective always assumes the same accurately centered angular position with respect to the microscope housing.Each objective can therefore carry exposed coded indicia, containing technical data concerning the objective, and the coding may be read by a reading device which is fixed with respect to the microscope housing. The code which is read for the objective indexed into working position may be used for aperture control in the microscope.

Abstract: An achromatic microscope objective having three lens components. The first and second components are individual positive lens elements and the third component is a cemented doublet made up of a negative element and a biconvex positive element. The objective is characterized by a particularly advantageous selection of the glasses used for the respective elements. The first or front element has an index of refraction in the range of 1.55 to 1.70 and an Abbe number in the range of 45 to 68; the second element has these same ranges; the third element (negative element of the doublet) has an index of refraction in the range of 1.65 to 1.97 and an Abbe number in the range of 20 to 40; and the fourth element (positive element of the doublet) has an index of refraction in the range of 1.46 to 1.57 and an Abbe number in the range of 50 to 85. By using glasses having these characteristics, it is possible to produce at modest expense a microscope objective with very good correction of all image errors.