System for visible light communication using single light source

摘要

According to one embodiment, there is provided a visible-light communications system in which bidirectional visible-light communication is performed between a visible-light communications device (10) and a mobile terminal (20). The device (10) has one light source (13). The mobile terminal (20) has a retroflection unit (25). The mobile terminal (20) further has optical filters (21B and 21R). The optical filter (21B) extracts a visible light beam (100B) modulated with the data transmitted from the visible-light communications device (10). The optical filter (21R) extracts a visible light beam (100R) that will be used as a retroflection light beam that is not modulated.