Patent ID: 8321304

Claim:
A stocked product sensing system comprising: a plurality of conducting plates associated with a product display and including at least a first conducting plate having a first plate area as or on and extending over a product display shelf surface, and a second conducting plate having a second plate area, each conducting plate arranged in a generally parallel, spaced, and fixed relationship with respect to at least one other conducting plate; a product space between the first conducting plate and the second conducting plate, wherein one or more product items are positioned within the product space and on the first conducting plate; a measuring circuit in communication with at least one of the first or second conducting plates, wherein the measuring circuit measures a capacitance between the first conducting plate and the second conducting plate; a processor in communication with the measuring circuit for receiving the measured capacitance, wherein the processor compares the measured capacitance to a predetermined capacitance value to derive a level of product availability on the first conducting plate within the product space, wherein the measured capacitance differs from the predetermined capacitance value due to a change in permittivity between the first conducting plate and the second conducting plate; and a user interface providing an output of the capacitance.