Photoelectric process for measuring and adjusting the position of objects, particularly of scale lines

Claim 1

A PHOTOELECTRIC PROCESS FOR MEASURING AND ADJUSTING THE POSITION OF OBJECTS, PARTICULARLY OF SCALE LINES BY MEANS OF SYMMETRY ADJUSTMENTS, WHEREIN A SCALE LINE OR AN IMAGE THEREOF OSCILLATES ABOUT A ZERO POSITION RELATIVE TO A DIAPHRAGM, TO AN IMAGE OF THE LATTER OR TO A LIGHT SOURCE, THE LATTER EMANATING A LIGHT BEAM THROUGH THE DIAPHRAGM ONTO A PHOTOELECTRIC CELL, COMPRISING THE STEPS OF OSCILLATING SAID SCALE LINE AND AN IMAGE OF THE LATTER, RESPECTIVELY, ABOUT A SYMMETRY LINE BY MEANS OF A LIGHT BEAM TO FORM SHADING AREAS FOR AN AMPLITUDE SUCH THAT AT THE GREATEST OSCILLATION SAID SHADING AREAS AMOUNTS TO A FRACTION OF THE MAXIMUM POSSIBLE SHADING BY SAID OSCILLATION, DURING AN OSCILLATION DISPOSED SYMMETRICALLY TO SAID SCALE LINE AND AN IMAGE OF THE LATTER, RESPECTIVELY, AND MEASURING THE AMPLITUDE DEVIATIONS OF SAID LIGHT BEAM IMPINGING ON SAID PHOTOELECTRIC CELL.