Pulsed wireless directional object counter
Document Type and Number: United States Patent 7448548
Abstract: A directional object counter uses two or more light sources to generate pulses of light, which travel on two light paths across a passageway. Light from both sources illuminates two sensors, after the light has traversed the passageway, and a processor connected to the sensors determines, based on the pulsed nature of the sources, which source(s) is/are illuminating which sensor(s), and counts movement of objects through the light paths in an identified direction. The pulsed nature of the light permits low-power operation of the directional object counter with a battery. Furthermore, the independence of the pulse discrimination from the pulse generation, enables the light sources and light sensors to be positioned on opposite sides of a passageway without wiring connecting them across the passageway.