JPS6489241A - Knocking treatment method for cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent damage of a resisting body of an intra-tube resistor and the tube wall at the neck part even when the knocking voltage is comparatively high, by fitting a ring given the grounded voltage or a low voltage on the periphery of the neck part. CONSTITUTION:A ring-shaped electrode member 50 is fitted on those peripheral parts of the neck 8a of a tube 8 to be equipped with fluorescent surface where No.1 and No.2 electrodes of an electron gun framing 9 are arranged, and the edges at the fluorescent surface 30 side are located in the corresponding position between No.3 electrode and No.2 electrode of the electron gun framing 9, and then a high voltage is impressed to No.3 and No.5 electrodes of the electron gun framing 9 through an anode terminal 23. At the same time, the grounded voltage or a low voltage is supplied to No.1, No.2 and No.4 electrodes of the electron gun framing 9 and also the ring-shaped electrode member 50, and desired discharge is generated between electrodes, and the potential at the part facing an intra-tube resistor 7' on the inner wall of the neck 8a at the time of knocking treatment is lowered. This can prevent damage of the resisting element of the intra-tube resistor and the tube wall at the neck.