Lighting control device and control method
US7633243B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 23, 2007 |
| Grant date | Dec 15, 2009 |
| Priority date | — |
| Expiry date | Jul 18, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a headlamp luminance controlling device, a CPU 21 first decides a luminance factor D based on a state of each switch 10 to switch 12 and a signal from a sensor 13. The CPU 21 determines an initial value of a PWM duty ratio S from the luminance factor D with a load current Ap as a default value (rated current A0). The CPU 21 starts the initial driving of a headlamp HL using the duty ratio S. The CPU 21 then determines the luminance factor D based on the state of each switch 10 to switch 12 and the signal from the sensor 13. Next, the CPU 21 determines the PWM duty ratio S based on the luminance factor D and the load current Ap detected by the headlamp current detector 23. The CPU 21 drives the headlamp HL using the PWM duty ratio S.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.