Illumination light communication device, and illumination apparatus and system including same
US8810155B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2012 |
| Grant date | Aug 19, 2014 |
| Priority date | — |
| Expiry date | Dec 13, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B47/1965
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An illumination light communication device includes a power supply unit controlling a load current in a light source unit to be maintained constant based on a dimming signal; an impedance unit series connected to the light source unit; a switch element parallel connected to the impedance unit to connect/disconnect the impedance unit with the light source unit; and a control unit controlling on/off of the switch element to modulate a light intensity of the light source unit such that a binary communication signal is superimposed on illumination light therefrom. The control unit controls the impedance of the impedance unit such that a difference between magnitudes of the load currents respectively when the pulse of the communication signal is superimposed and is not superimposed is maintained constant regardless of a dimming rate of the dimming signal in a range of a dimming rate equal to or greater than a predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.