Shadow mask for cathode ray tube and method of manufacturing same
US6313573A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1999 |
| Grant date | Nov 6, 2001 |
| Priority date | — |
| Expiry date | Jan 21, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/0738
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A shadow mask includes an aperture portion having a plurality of apertures formed therein, the aperture portion being formed over a predetermined area in a center of the shadow mask; and a non-aperture portion defining a periphery of the shadow mask and formed adjacent to the aperture portion. Only the aperture portion is selectively heat-treated to result in a tensile strength of the aperture portion being 1.2 to 3 times greater than that of the non-aperture portion, and the modulus of elasticity of the aperture portion being 1.5 to 3 times greater than that of the non-aperture portion. The method includes the steps of selectively performing a heat-treating process on only the aperture portion of the shadow mask by mounting a separating cover on the non-aperture portion, the separating cover preventing contact of the non-aperture portion with the gaseous atmosphere present during the heat treating process. The shadow mask is then press-formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.