Patent ID: 11896144
Assignee: AMAZON TECHNOLOGIES, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC A  G | IPC A  G

Claim 6:
7. A method comprising:
capturing, by a camera, a first image at a first time,
wherein a first counting device is within a field of view of the camera,
wherein the first counting device is provided in association with a first shelf,
wherein a first portion of the first counting device having a first visible pattern thereon is configured to rotate about a first axis in response to changes in position of a first pusher slidably disposed in a first track on the first shelf, and
wherein a first plurality of items is provided between a first contact face of the first pusher and the first end of the shelf at the first time;

determining a first orientation of the first visible pattern within the first image;
capturing, by the camera, a second image at the second time;
determining a second orientation of the first visible pattern within the second image;
determining a change in position of the first pusher between the first time and the second time based at least in part on a difference between the first orientation and the second orientation;
calculating a number of the first plurality of items based at least in part on the change in position; and
determining that an interaction involving the number of the first plurality of items occurred between the first time and the second time.