Ernst Leitz Wetzlar Gmbh

Werner Nickel

Robert Lisfeld

Guenter Reinheimer

A semi-automatic coarse-fine focusing apparatus for microscopes adjusts the focus of a microscope through rotation of a shaft which rotates a pinion that drives a rack to reciprocate. The rack carries a specimen being observed by the microscope. The shaft which rotates the pinion is in turn driven by a gear that is meshed with a helix formed on a cylinder by a helical thread disposed therearound. The helix is non-rotatably mounted on another shaft that includes a knob which is manually turned to turn the helix and thus rotate the gear for coarse adjustment. The helix is preferably rigidly mounted on the shaft and the shaft is slidable. One arm of a bell crank engages an end face of the helix to reciprocate the helix and thus rotate the gear for fine adjustment. The other arm of the bell crank is engaged by a cam which pivots the bell crank according to the position of the cam. The position of the cam is determined by an electric motor which is preferably controlled by signals that vary with image contrast. Other signals may be generated by a shutter which has apertures which correspond to various positions of the cam.

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Munich, Georgia

Werner Nickel