Patent ID: 7005790

Claim:
A glass funnel for a cathode-ray tube, having a shape of a funnel with a rectangular larger opening portion at one end and a smaller opening portion at the other end, said larger opening portion being composed of major sides across a minor axis, minor sides across a major axis, and corners on a diagonal axis, the corners continuing between said major sides and said minor sides, the glass funnel 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 for 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, within a range excluding said corners, has a first region of predetermined dimension measured from said seal edge surface in a direction parallel to a tube axis and a second region excluding said first portion; when constituting a cathode-ray tube, said first region falls on a region to undergo tensile vacuum stress resulting from a vacuum pressure in said cathode-ray tube; said second region has a thickness smaller than a thickness of said first region, so that a boundary portion between said first region and said second region forms a stepped portion on an external surface of said body portion.