System and method for controlling the exposure of color picture tube phosphor screens
US4436394A · kind A · utility
1Cited by
10References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 28, 1981 |
| Grant date | Mar 13, 1984 |
| Priority date | — |
| Expiry date | May 28, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/2272
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The light intensity-exposure time product of a lighthouse used in the manufacture of phosphor screens for color picture tubes is held constant despite changes in the shadow mask light transmission characteristic and power supply variations. The power provided to the exposing lamp is monitored and converted to a square wave output having a frequency which varies with the power. The frequency variations change the exposure time inversely with the frequency changes to maintain the light intensity-exposure time product constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.