Lighting device, lighting fixture, lamp, and sound emission prevention method
US9210743B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 2, 2013 |
| Grant date | Dec 8, 2015 |
| Priority date | — |
| Expiry date | May 19, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lighting device including: a lighting circuit; a drive circuit; a dimmer control circuit; and an LPF, the drive circuit for increasing on-time as a pulse height increases when an inputted PWM signal satisfies a first condition where a pulse height is greater than a first threshold and less than a second threshold greater than the first threshold, and making the on-time for which a switching element is on when the switching element turns on and off once in a burst period, constant in a second condition where the height pulse is greater than the second threshold, the LPF generating a smoothedPWM signal which has a first time period satisfying the first condition and a second time period satisfying the second condition in a signal interval indicating a duty ratio, and outputting the smoothed PWM signal to the drive circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.