Device having multiple luminescent segments
US6509885B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2000 |
| Grant date | Jan 21, 2003 |
| Priority date | — |
| Expiry date | Apr 5, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/0233
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A segment-type electroluminescent display panel is driven by a driving circuit that supplies a constant current to each luminescent segment. The display panel includes plural luminescent segments each having a luminescent area different from one another. The plural segments are grouped into several groups, so that each group includes the segments having the same or similar luminescent area. The amount of current to be supplied to each segment is determined group by group so that a substantially same current density is supplied to all the segments. Since the plural segments are grouped according to their size, the driving circuit is simplified while attaining an equal luminance among all the luminescent segments. Alternatively, an equal amount of current is supplied to all the variously sized segments, and a resistor is connected in parallel to each segment to equalize the current density supplied to each segment thereby to achieve an equal luminance among all the segments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.