Method of forming a color picture tube shadow mask
US5263887A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1991 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Mar 11, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/142
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides an improved method of forming a shadow mask for a color picture tube from a flat apertured mask. The mask has an central apertured portion, a solid border portion and a skirt portion. The improved method comprises several steps. First, a flat apertured mask is placed beneath an upper punch. Next, the periphery of the mask at the skirt portion is clamped. The punch then is pressed against the mask to contour the mask in its central apertured and solid border portions. Thereafter, the periphery of the mask at the skirt portion is unclamped, and the solid border portion of the mask is pressed between a bead die and the punch to form a peripheral bead in the solid border portion of the mask. Finally, the skirt portion is swept back to substantially parallel a central longitudinal axis of the formed mask, while the border portion is held between the bead die and the punch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.