Patent attributes
An assistant microscope add-on device for a surgical microscope (1) comprises an objective (22) inclined relative to an object plane (10) with an object field (10′), wherein the objective defines an objective plane (22′) and an objective axis (16′) perpendicular thereto forming an angle α larger than 0° to the surface normal of the object plane (10). A tube (23) and an eyepiece (24) having an eyepiece lens (27) defining an eyepiece plane (27′) and an eyepiece axis (35) perpendicular thereto. Due to the oblique viewing angle, an intermediate image plane (26) to be imaged by the eyepiece (24) is inclined relative to the objective plane (22′). The resulting aberration is eliminated by the eyepiece axis (35) and the objective axis (16′) forming an angle β of larger than 0°, wherein the angle β is so chosen that the eyepiece axis (35) is substantially perpendicular to the intermediate image plane (26). Consequently, the object field (10′) is imaged free of distortion and sharply across the entire image area.
