Cathode ray tube with heat-shrink band having high stress of yielding point and method of fabricating the same
AssigneeSony Corporation
InventorsIchiro Saito, Shiro Kenmotsu, Tomio Aoki
Life of this patent
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Abstract
A heat-shrink band for a cathode ray tube (CRT) has a light weight, corrects the deformation of an object, such as a panel of a CRT due to the air pressure, effectively prevents implosion of the CRT, can suppress the color deviation, and in addition is excellent in formability. The method of fabricating the heat-shrink band includes a composition of cold rolled steel sheet such that the heat-shrink band offers both a high elongation characteristic at an ambient temperature and a high stress of yielding point characteristic after the heat-shrink process. The reduction of the weight of the heat-shrink band contributes to an overall reduction of the weight of the CRT.
Claims7
A cathode ray tube comprising:
- a panel portion;
- a funnel portion joined to said panel portion;
- an electron gun positioned inside a neck portion formed at a rear end of said funnel portion;
- and
- a heat-shrink band which is to be thermally expanded and fitted over an outer periphery of the panel portion and which is formed of material having at least a 20% elongation at an ambient temperature and at least a 40 kg/mm.sup.2 stress of yielding point after the heating and cooling.
A method of fabricating a cathode ray tube comprising the steps of:
- joining a panel portion to a funnel portion;
- positioning an electron gun inside a neck portion formed at a rear end of said funnel portion;
- evacuating the tube comprising the panel portion and the funnel portion;
- fitting a thermally expanded heat-shrink band which is formed of material having at least a 20% elongation at an ambient temperature and at least a 40 kg/mm.sup.2 stress of yielding point after the heating and cooling over an outer periphery of the panel portion;
- and
- rapidly cooling said heat-shrink band.
Dependencies are inferred from the claim text.