LED-switching controller and LED-switching control method
US7436378B2 · kind B2 · utility
34Cited by
4References
5Claims
0Family size
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Key dates
| Filing date | Oct 2, 2004 |
| Grant date | Oct 14, 2008 |
| Priority date | — |
| Expiry date | Dec 2, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An LED terminal monitoring circuit detects an LED at the lowest potential among a plurality of parallel-connected LEDs. An analog signal selecting circuit gives a signal indicating the voltage of the detected LED to a boosting circuit. The boosting circuit performs a boosting operation on the basis of the condition of the detected LED at the lowest voltage and, consequently, a voltage sufficient for driving the LEDs in a current-control mode can be applied to all the LEDs. Signal lines not connected to LEDs are excluded from objects of a LED-switching control operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.