CRT with non-circular cone and yoke

A cathode ray tube comprising:

• a vacuum envelope having a substantially rectangular face panel, a cylindrical neck, and a funnel extending between the face panel and the neck, the funnel having a cone portion whose outer circumference is gradually enlarged from an end of the cone portion on a side of the neck in a direction toward the face panel, and a funnel body whose outer circumference is sharply enlarged from an end of the cone portion on a side of the face panel in a direction toward the face panel;
• an electron gun arranged in the neck, for emitting electron beams toward the face panel;
• and
• a deflection yoke installed on the envelope and extending from an outer circumference of the neck to an outer circumference of the cone portion, the deflection yoke including a hollow magnetic core, and a horizontal deflection coil and a vertical deflection coil provided on an inner surface side of the core, for deflecting the electron beams emitted from the electron gun;
• at least a part of each of lateral cross-sections of an outer surface of the cone portion and an inner surface of the core, perpendicular to a center axis of the funnel, having a non-circular shape, and a gap between the lateral cross-sections of the outer surface of the cone portion and the inner surface of the core includes a non-uniform portion.