Method and apparatus for calibrating deflection in an oscilloscope

摘要

The cathode-ray-tube beam deflection of an oscilloscope is automatically calibrated by photo-electrically detecting the intersection of the tube's electron beam with visible graticule limes on the tube's faceplate. An input signal is compared, at the time of intersection, with stored values representative of the graticule lines, and the deflection amplifier gain of the oscilloscope is adjusted until the graticule lines properly represent the measurement of the input signal.