Low current drive of light emitting devices
US6191534A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1999 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Jul 21, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2330/028
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Control circuitry for an array of light emitting devices includes a first column line connected to each light emitting device in a column of light emitting devices. First column circuitry includes a first current source and a second current source. The first current source is connected to the first column line. The second current source is connected to the first column line. When a first light emitting device from the column of light emitting devices is to be turned on, the first current source is turned on until a voltage on the first column line is equal to a predetermined voltage. Then the first current source is turned off and the second current source supplies current sufficient to cause the first light emitting device to emit light to a first brightness level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.