Color picture tube with reduced primary and secondary moire
US5525858A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Nov 21, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/075
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved color picture tube, operable in a multistandard television receiver, includes a viewing screen, a shadow mask and an electron gun for generating and projecting three electron beams through the shadow mask and onto the screen. The screen includes phosphor lines that extend in a first direction. The electron beams are subject to deflection in the first direction and in a second direction, that is substantially perpendicular to both the first direction and the phosphor lines. The shadow mask includes elongated slit-shaped apertures that are aligned in columns that substantially parallel the phosphor lines. The adjacent apertures in each column are separated from each other by tie-bars in the mask, and the tie-bars in one column are offset from the tie-bars in adjacent columns in the first direction. The improvement includes the tie-bars in alternate columns lying on substantially straight lines that form an angle of approximately 2 degrees with respect to the second direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.