Instrument panel and EL lamp thereof
US5361017A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1993 |
| Grant date | Nov 1, 1994 |
| Priority date | — |
| Expiry date | Feb 1, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Each of a plurality of EL lamps in an instrument panel has its own control circuit for connecting the lamp to an adjustable AC voltage source. Each control circuit includes a photodetector for detecting the intensity of the illumination of its associated lamp, when the lamp is energized. With respect to a given input voltage of the AC voltage source, when the intensity of the light emitted by a given lamp begins to diminish, its control circuit will automatically increase the AC voltage applied across the electrodes of the lamp, thereby maintaining the light intensity of the lamp regardless of its age, for a given AC input voltage to the control circuit. The intensity of each lamp therefore remains consistent throughout substantially the full life of the EL lamp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.