Incandescent matrix display with high frequency lamp driving
US4894645A · kind A · utility
2Cited by
8References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 27, 1988 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | May 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G3/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an electronic sign with a number of light bulbs provided in rows and columns (so called matrix), whereby said bulbs (L) are turned on row by row or column by column (so called multiplex operation). For increasing the life of the bulbs (L), said bulbs (L) are operated by alternating current at high frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.