PROCESS AND DEVICE TO MEASURE THE CONVERGENCE IN A THREE GUN CATHODE RAY TUBE WITH A PERFORATED MASK

摘要

Monochrome bar patterns approximately seven millimeters in width are produced on the screen of a three-color television picture tube by means of a video signal having a substantially Gaussian waveform. The value of the convergence component is given by the distance between centers of two bars of different colors. Measurement of convergence is carried out by means of a photosensor consisting of a charge-coupled photosensitive strip and an optical system comprising a biconvex lens and a cylindrical lens.