US 6,963,163 B2 · Color cathode ray tube having DC magnetic field during degaussing process

Abstract

A color cathode ray tube having a striped phosphor screen is provided, in which color displacements due to the tube axis (Z-axis) component of the terrestrial magnetism can be decreased at low cost. A positive temperature coefficient thermistor and a degaussing coil are connected in series to an AC power source (AC 100V) via a switch. A rectifier/smoothing circuit is provided in parallel to the positive temperature coefficient thermistor. When the switch is turned on, an ordinary degaussing process due to the AC attenuating magnetic field interlinked to the degaussing coil is performed, and the DC magnetic field in the Y-axis direction interlinked to the degaussing coil decreases the influence of the terrestrial magnetism in the tube axis direction (Z-axis direction).

Claims7

Dependent claims

A color cathode ray tube comprising:

a bulb including a face panel having in its inner surface a phosphor screen made of phosphors of a plurality of colors, and a funnel connected to the rear of the face panel;
an electron gun installed in a neck portion of the funnel;
a shadow mask having a plurality of apertures for passing an electron beam emitted from the electron gun, and arranged at a predetermined spacing from the phosphor screen;
and
an inner magnetic shield extending from a rear portion of the shadow mask toward the electron gun;
and
a degaussing coil mounted on the outer surface of the funnel;
wherein a DC magnetic field is generated by superimposing a DC current on the degaussing coil during a degaussing process that is performed by supplying an AC degaussing magnetic field to the degaussing coil.

5 more elements

Dependencies are inferred from the claim text.

Color cathode ray tube having DC magnetic field during degaussing process

Life of this patent

Color cathode ray tube having DC magnetic field during degaussing process

Life of this patent

Abstract

Claims7