GLASS BULB FOR CATHODE-RAY TUBE AND CATHODE-RAY TUBE

摘要

A glass bulb for cathode-ray tubes having a light weight, a small depth, and a high safety, comprising a yoke portion having a non-circular cross section, and consuming less power for deflecting the electron beam. The glass bulb comprises a yoke portion having a non-circular cross section. The relation between the distance H from the center of the inner surface of a face portion to a reference line and the length D of the diagonal of the screen is expressed by D/H >=3.0. When the position 50 mm apart from the yoke end toward the seal edge portion along the surface of the body portion is referred to as a yoke end vicinity portion, the boundary between the neck portion and the yoke portion is referred to as a neck seal position, and the region extending from the yoke end vicinity position to the neck seal position and coming under a tensile stress of 8 MPa or more when the inside of the glass bulb is evacuated into a vacuum state is referred to as a highly strained region, the glass bulb has a chemically strengthened compression stress layer at least on the outer surface of the highly strained region from the yoke end vicinity position to the yoke end and/or the highly strained region from the neck seal position to the yoke end.