Drive circuit for electroluminescent element
US4443741A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1981 |
| Grant date | Apr 17, 1984 |
| Priority date | — |
| Expiry date | Sep 14, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit for an electroluminescent (EL) element whose brightness can be changed by changing a voltage or the frequency of the voltage applied to the EL element and can be kept constant by keeping the current flowing through the EL element constant is disclosed. The drive circuit is provided with a drive power source whose output voltage or output voltage frequency is variable by a control signal. The output of the drive power source is supplied to the EL element. The current flowing through the EL element is detected by a current detecting element and a signal related to the detected current is applied as the control signal to the drive power source to subject the EL element to a constant-current drive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.