Abstract: Color cathode-ray tube comprising a color selection mask (16) held under tension between a first pair of opposed long sides (30) of an approximately rectangular metal frame (21), a main magnetic screen (22) placed at the rear of the frame in the funnel-shaped part (11) of the tube's envelope, and additional means (50) for forming a screen against the Earth's magnetic field in the part lying along the second pair of opposed short sides of the frame.

Abstract: A method and apparatus for improving magnetic shielding in mask-frame-assemblies. The system includes providing a cathode ray tube, a mask frame assembly disposed within the cathode ray tube and at least one magnetic shield disposed on the edge of the mask frame assembly. These magnetic shields provide shielding for the horizontal component of the terrestrial magnetic field and thus reduces distortion in the picture displayed on the tube.

Abstract: Color cathode-ray tube comprising a color selection mask (16) held under tension between a first pair of opposed long sides (30) of an approximately rectangular metal frame (21), a main magnetic screen (22) placed at the rear of the frame in the funnel-shaped part (11) of the tube's envelope, and additional means (50) for forming a screen against the Earth's magnetic field in the part lying along the second pair of opposed short sides of the frame.

Abstract: A method and apparatus for improving magnetic shielding in mask-frame-assemblies. The system includes providing a cathode ray tube, a mask frame assembly disposed within the cathode ray tube and at least one magnetic shield disposed on the edge of the mask frame assembly. These magnetic shields provide shielding for the horizontal component of the terrestrial magnetic field and thus reduces distortion in the picture displayed on the tube.

Abstract: A compensating coil for a scanning electron beam display such as a color television tube reduces undesirable deflection of the electron beams due to ambient magnetic fields, in particular the geomagnetic field. A first coil section has at least one winding disposed to encircle the tube neck, perpendicular to the Z axis. Upper and lower coil sections are disposed above and below the first coil section, each inclined forwardly along the Z axis and having a loop encompassing an area extending in the X and Y directions generally following the surface of an internal magnetic shield. The coil sections are coupled in series. The upper and lower coil sections have a wider X axis dimension proceeding forwardly along the Z axis, being keystone shaped. Lateral lengths of the upper and lower coils sections connect to the first coil section at lateral sides, such that the compensating coil is a continuous winding. The first coil section may have two passes for each pass of the upper and lower coil sections.