Low stock alert system
View Patent ↗A low product stock display system for detecting at least one of fully stocked, partially stocked, and empty (no stock) shelf has been described. The presence/absence of stock can be detected by conductive contact sensors, inductance sensors, weight sensors, optical sensors, and, in the preferred embodiment, with an RF transmission line. The data from a sensor is wirelessly relayed to an external server for processing across a plurality of facilities, and can provide alerts to personnel or systems responsible for reordering or restocking the particular shelf or display at the facility.
1. 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.
2. 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, the sensor comprising an optical sensor that generates product availability status data signals representing at least one of fully stocked, empty, and partially stocked product availability, wherein the optical sensor comprises a light-beam sensing device for purposes of monitoring presence/absence of product availability; 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 light-beam sensing device comprises:
a number of lights on one side of columns of product for generating a light beam, one light beam for each column of product;
a corresponding number of photoelectric cell light sensors on an opposite side of each column of product; and
a pulsing circuit coupled to each of the lights to pulse the lights periodically in succession whereby the presence of product interrupts the light beam causing one or more of the light sensors to signal one of an empty/non-empty product availability state for each column of product.
3. 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, the sensor comprising a conductive contact sensor detecting varying dielectric properties of product present on each shelf; 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 conductive contact sensor comprises:
at least one pair of wires on each shelf, each pair of wires separated by a distance sufficient to allow product to rest on both wires in a given pair such that one or more stocked product resting on a pair of wires causes the electrical resistance across the wire pair to be varied;
a low voltage source, sufficiently low to protect the product, coupled to each pair of wires; and
a tag, including a microprocessor on the tag, for monitoring changes in voltage on the wires because of the presence/absence of stocked product.
4. The system of claim 3 , further comprising a separate monitoring of each wire pair to detect the presence/absence of stocked product within and/or across each shelf.
5. 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:
a radio based stocked product availability detector utilizing RF signals that are output to a well matched transmission line and becomes mismatched when items are present on a shelf; and
a signal detector for determining the amount of RF signal reflection caused by the change in impedance of a transmission line and the line to become mismatched and reflect signals thereby detecting the presence/absence of stocked product.
6. The system of claim 5 , wherein the radio based stocked product availability detector further comprises:
an RF signal transmission line having first and second ends and air space on at least one side;
a resistor terminating the first end of the transmission line in its characteristic impedance to absorb the transmitted RF energy;
a directional signal detector being coupled to the second end of the transmission line for detecting signal reflections caused by a mismatch of the line due to the presence of product;
an RF signal generator providing RF signal pulses to the directional signal detector for application to the RF signal transmission line; and
a threshold detector coupled to the directional signal detector for measuring the signals reflected by the stocked product to determine presence/absence of the stocked product.
7. The system of claim 6 , wherein the transmission line comprises a microstrip line.
8. The system of claim 6 , wherein the transmission line comprises elongated parallel lines.
9. 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, the sensor comprising a weight sensor that generates shelf product availability status data signals representing at least one of fully stocked, empty, and partially stocked product availability; 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 weight sensor comprises:
at least two layers of flexible conductive material on which the stocked product is to be placed; and
a dielectric material disposed between the at least two layers of flexible material, whereby the weight sensor produces relatively low resistance readings across the layers of flexible conductive material when a stocked product is placed on said flexible material and produces relatively higher resistance readings across the layers of flexible conductive material when a stocked product is low or no longer on the shelf.
10. A low stock-alert sensing system, comprising:
a display device for stocking products;
an inductance sensor associated with the display device and that generates a sensor signal;
the inductance sensor including an electrically conducting wire that forms a loop, the loop generating a magnetic field that varies with an amount of stocked products on the display device, wherein the sensor signal is generated based on the magnetic field; and
an RF tag coupled to the inductance sensor and relaying the sensor signal to a remote location for processing.
11. A low stock-alert sensing system, comprising:
a display device for stocking products;
a light-beam sensing device associated with the display device and configured to generate a sensor signal; and
an RF tag coupled to the light-beam sensing device and relaying the sensor signal to a remote location for processing:
the light-beam sensing device including:
a light attached at a first location on the display device for generating a light beam;
a photoelectric cell attached at a second location on the display device and being positioned to detect the light beam; and
a pulsing circuit coupled to the light and configured to pulse the light periodically,
wherein the presence of product on the display device interrupts the light beam causing the light-beam sensing device to generate the sensor signal with an indication of the presence of the product on the display device.
12. A low stock-alert sensing system comprising:
a display device for stocking products;
a conductive contact sensor configured to detect properties of products present on the display device and to generate a product availability status data signal;
an RF tag coupled to the conductive contact sensor and configured to relay the product availability status data signal to a remote location for processing;
the conductive contact sensor comprising:
a pair of wires disposed on the display device and separated by a distance sufficient to allow a product to rest on both wires causing the electrical resistance across the pair of wires to be varied;
a low voltage source coupled to the pair of wires;
a processing device configured to monitor changes in voltage on the pair of wires due to the presence or absence of stocked products.
13. A low stock-alert sensing system, comprising:
a display device for stocking products;
a sensor configured to sense the presence or absence of stocked product on the display device and to generate a product availability status data signal; and
an RF tag coupled to the sensor and configured to relay the product availability status data signal to a remote location for processing;
the sensor comprising:
a radio based stocked product availability detector utilizing RF signals that are output to a matched transmission line and that become mismatched when an item is present on the display device; and
a signal detector configured to detect an amount of RF signal reflection caused by a change in impedance of the matched transmission line, wherein the presence or absence of stocked products on the display device is determined based on the amount of RF signal reflection.
14. A low stock-alert sensing system, comprising:
a display device for stocking products;
a weight sensor disposed on the display device and configured to generate a shelf product availability status data signal that indicates the presence or absence of stocked product on the display device; and
an RF tag coupled to the weight sensor and configured to relay the shelf product availability status data signal to a remote location for processing;
the weight sensor comprising:
two layers of flexible conductive material on which the stocked products are to be placed; and
a dielectric material disposed between the two layers of flexible material, wherein the weight sensor produces a first range of resistance readings across the layers of flexible conductive material when a product is placed on the flexible conductive material and produces a second range of resistance readings across the layers of flexible conductive material when the product is not on the flexible conductive material.