Lighting device and illumination apparatus using the same
US9295119B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 2014 |
| Grant date | Mar 22, 2016 |
| Priority date | — |
| Expiry date | Sep 10, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A controller has a first mode and a second mode. First mode is of generating a PWM signal that has a duty ratio to be changed according to a luminous level for a light emitting element and has a constant amplitude. Second mode is of generating a PAM signal that has a constant duty ratio and has an amplitude to be changed according to the luminous level for the light emitting element. Controller is configured to apply one of PWM signal in first mode and PAM signal in second mode to a control terminal of a switching element, when the luminous level is a predetermined level or more. Controller is configured to apply the other of PWM signal in first mode and PAM signal in second mode to the control terminal of the switching element, when the luminous level is less than the predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.