Patent ID: 11922371
Assignee: 7-ELEVEN, INC.
Field: Measurement (Instruments)
Classification: CPC G  A  H | IPC A  G  H

Claim 16:
17. A system for counting items stored in a rack, comprising:
a longitudinal rack that stores a plurality of items along the length of the rack between a front end and rear end of the rack;
a shoe movably attached to the rack such that the shoe travels between the front end and the rear end of the rack, wherein the items are placed adjacent to a front end of the shoe, wherein the shoe is pushed back towards the rear end of the rack with each item loaded on the rack;
a magnet coupled to the shoe;
a longitudinal circuit board arranged along the length of the rack and comprising:
an array of sensors arranged along the length of the circuit board, wherein:
a spacing between each pair of the sensors corresponds to a thickness of an item such that, for any number of items stored in the rack, the magnet is directly above one of the sensors;
each of the sensors generates a zero voltage value or a near zero voltage value when the magnet is above the sensor and neighboring sensors on either side of the sensor generate half of a maximum absolute voltage value or near half of the maximum absolute voltage value; and
each sensor corresponds to a particular number of items placed in the rack based on the position of the sensor on the circuit board;

a memory that stores voltage values generated by the sensors; and
a processor coupled to the sensors and the memory, wherein the processor is configured to:
monitor the voltage value generated by at least a subset of sensors of the array of sensors;
detect that a first sensor has generated a first highest absolute voltage value and a second sensor has generated a second highest absolute voltage value, wherein the first highest absolute voltage value and the second highest absolute voltage value are the two highest voltage values out of the voltage values generated by the sensors in the array;
in response to the detecting, determine that the magnet is positioned above a third sensor that is disposed between the first sensor and the second sensor; and
determine a number of items actually stored in the rack based on the particular number of items corresponding to the third sensor that is disposed between the first sensor and the second sensor.