Patent ID: 7233241

Claim:
A low stock-alert sensing system comprising: at least one display device for stocking a product, the at least one display device comprising at least one shelf for stocking products; a sensor associated with each display device for sensing presence/absence of stocked product and generating a product availability status data signal; and an RF tag coupled to the sensor for receiving the sensor signals and relaying the sensor signals to a remote location for processing, the RF tag being an RFID tag that stores an identification data signal representing the at least one display device; wherein the RF tag relays the received product availability status data signal with the display identification data signal to a remote location for processing; wherein the sensor for sensing presence/absence of stocked product and generating a product availability status data signal comprises: an inductance sensor that generates shelf product availability status data signals representing at least one of fully stocked, empty, and partially stocked product availability; wherein the inductance sensor comprises: an electrically conducting wire associated with each display shelf to form at least one loop on each shelf for generating a magnetic field whose signal strength varies with amount of stocked product on the associated display shelf and represents the stock presence/absence data signal; the RFID tag is coupled to the at least one of the electrically conductive wires on at least one of the display shelves for receiving the magnetic field strength signal; and a circuit forming part of said tag for deciphering the magnetic field strength signal to determine product availability on the at least one of the display shelves.