Patent ID: 7026752

Claim:
A glass funnel for a cathode-ray tube, having a shape of a funnel with a larger opening portion at one end and a smaller opening portion at the other end, comprising a seal edge portion extending from a seal edge surface of said larger opening portion to a mold match line, a yoke portion to be equipped with a deflection yoke, said yoke portion being arranged at a side of said smaller opening portion, and a body portion continuing between said mold match line and said yoke portion, wherein: said seal edge surface has a thickness almost equal to a thickness of a seal edge surface of a glass panel for a cathode-ray tube to be joined thereto; said body portion has a region of dimension h measured from said seal edge surface in a direction parallel to a tube axis and the other region excluding said region of dimension h; when constituting a cathode-ray tube, said region of dimension h falls on a region to undergo tensile vacuum stress resulting from a vacuum pressure in said cathode-ray tube; said other region has a thickness smaller than a thickness of said region of dimension h, so that a boundary portion between said region of dimension h and said other region forms a stepped portion on an external surface of said body portion; said stepped portion has a step ΔT of 0.06≦ΔT/S≦0.3 with respect to a thickness S of said seal edge surface.