Shadow mask for use in a three-gun color picture tube
US5055736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1990 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Mar 30, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/076
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A shadow mask for use in a three-gun color picture tube comprising a number of electron beam transmission holes, the length of the bridge portion between two vertically adjacent ones of said electron beam transmission holes being constant, the vertical pitch of said electron beam transmission holes being varied between Py+.DELTA.x and Py-.DELTA.x so as to reduce moire effect, .DELTA.x being obtained from the following formula when n=3, 4: ##EQU1## wherein Py is the vertical pitch of the electron beam transmission holes of a shadow mask, Ps the pitch of scanning lines, fa the pitch frequency of the shadow mask, and fs the scanning frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.