Abstract: A color cathode ray tube includes an automatic convergence unit employing index elements on the reverse surface of a color-selective electrode. The paste used for forming the index elements has a composition consisting essentially of index phosphors, an inorganic adhesive and water to assure the adhesive force of the index elements onto the color selective electrode to prevent peeling of the index elements while facilitating the coating operation for formation of the index elements.

Abstract: An electronic circuit automatically corrects the convergence of an electron beam of a color cathode ray tube. Light reflected upon scanning by the electron beam of an index pattern disposed at a predetermined position on the shadow mask of the color cathode ray tube is detected by a photodetector. A detected signal representative of the scanning position of the electron beam is obtained, and convergence error information is obtained based on the detected signal. The correcting circuit comprises an integrator for integrating the detected signal produced during a plurality of traverses of the index pattern by the electron beam. The convergence error information is based on the result of the integration. The effect of noise included in the detected signal is thereby reduced, and convergence correction with increased accuracy is obtained.

Abstract: A resistor for use in a cathode ray tube comprises an insulating plate provided thereon with at least first and second electrode terminals for use respectively with relatively high and low voltages in the cathode ray tube, a coating insulator provided on the insulating plate for covering the same, and a resistive layer provided in a predetermined pattern on the insulating plate between first and second electrode terminals to be covered by the coating insulator and accompanied with a piece of conductive layer provided on the insulating plate at an area between first and second electrode terminals including a high potential difference position where a relatively large potential difference is applied to the coating insulator when the resistor is used in the cathode ray tube.