Hitachi, Ltd.

Kenji Kawamata

Hiroshi Ito

Hisashi Nose

A color cathode ray tube includes a vacuum envelope comprised of a neck portion having a circular cross section and a funnel portion having a deflection yoke mounting region of pyramidal shape at a side which is connected to said neck portion. In this color cathode ray tube, an inflection edge in which an inner surface angle changes from an inner wall of the deflection yoke mounting region to a panel portion side inner wall of said funnel portion is formed on an inner surface of a funnel portion at a panel portion side terminal end of the deflection yoke mounting region, and an angle made by a straight line which passes through an endmost face of the inflection edge and is perpendicular to the tube axis and a tangent line at the endmost face is within 5&deg;-11&deg;. The pyramidal deflection yoke mounting region has the inner wall opening perpendicular to the tube axis direction formed in a pin cushion shape and recesses having a curvature are formed at respective corners. The distance between a first straight line which connects bottom portions of neighboring recesses of the corner portions and a second straight line which is in contact with a central point of an inner wall between the neighboring corners and is parallel with the first straight line is not more than 2.0 mm or preferably not more than 0.1 mm, provided that said tube axis direction is taken as &plus;.

Growing community of inventors

Sakura, Japan

Kenji Kawamata