Light emitting element drive device and electronic device light emitting element
US6949892B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 2003 |
| Grant date | Sep 27, 2005 |
| Priority date | — |
| Expiry date | May 1, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic apparatus includes a display device (20) and a drive device (10) for driving the display (20). The display device (20) is equipped with light emitting elements (21-26) such as LEDs driven at high voltages. The display device (20) has a multiplicity of light emitting element series each supplied at one end thereof with a high voltage (Vh) higher than a given power supply voltage (Vdd). The drive device (10) has drivers (12-14) each having one end connected to a respective terminal to which a corresponding one of said multiple light emitting elements series is connected. The drivers are turned ON and OFF in accordance with instruction signals (S1-S3) such that, when turned ON, they provide currents to the series connected. The drive device (10) also has a multiplicity of bypass current source (15-17) for providing the light emitting element series with currents not sufficient to activate the series for emission of light when corresponding drivers are turned OFF. The drive device can be constructed using ICs that are designed to operate at low voltages, thereby facilitating reduction of electric power loss by the electronic apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.