System and method for optical data communication

摘要

A system for data communication in a space illuminated by a plurality of illumination sources that are powered by a common power feed. The system includes a power modulation unit which is interposed in the common power feed, upstream of each of the illumination sources. The power modulation unit induces a change in the signal of the power feed in response to received data and effects variations in illumination intensity in the space provided by the illumination sources. The data is provided by a data source computer. At least one optical receiver is in the illuminated space and is in optical communication with at least one of the illumination sources. The optical receiver is responsive to changes in the incident light from the illumination sources resulting from the power modulation unit. The system can be used to communicate and display product data in an electronic shelf tag system.