Inventory Item Tracking via Hand-Crossing Image Detection

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Solution Overview

Problem

Existing systems for tracking and managing inventory in materials handling facilities require users to manually check out items, which is inefficient and time-consuming.

Innovation Solution

A system that uses image capture devices to detect the removal and placement of items by analyzing hand images before and after crossing an inventory location plane, combined with other sensors to confirm item identity, allowing for automatic item tracking and updating of user lists without manual checkout.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual checkout is used to track item movement, then item tracking can be performed, but the process is inefficient and time-consuming

Engineering Contradiction:
Improveitem tracking efficiencyVSAvoidcheckout time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces the manual mechanical checkout process with an automated optical detection system using image capture devices. The system automatically detects item removal and placement by capturing images of the user's hand before and after the inventory location plane, eliminating the need for manual scanning or checkout procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system enables self-service tracking where the user's own hand movements are automatically detected and processed by the imaging system. The user simply needs to perform the natural action of removing or placing items, and the system automatically tracks these movements without requiring any additional manual input or checkout actions from the user.

Inventive Principle:
Principle #25Self-service

2Productivity

If image capture devices are used to automatically detect item movement, then checkout efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvecheckout efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The image capture device serves multiple functions: it captures images of the user's hand for movement detection, provides visual verification of item removal/placement, and triggers the tracking process. This multi-functionality reduces the need for separate sensors or detection devices, thereby limiting the increase in system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the user's own hand as an intermediary object that naturally appears in the field of view during item removal or placement. By detecting hand movement across the inventory location plane, the system indirectly detects item movement without requiring direct contact sensors or complex detection mechanisms at the inventory locations themselves.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Extent of automation

If hand images are analyzed to detect item removal and placement, then automated tracking is achieved, but measurement precision requirements increase

Engineering Contradiction:
Improvetracking automationVSAvoidhand image analysis precision
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The system does not require complete or excessive analysis of the entire image. Instead, it focuses on detecting the basic movement of the hand across the inventory location plane, which is sufficient to trigger item tracking. This partial action approach reduces the precision requirements compared to fully analyzing hand gestures or item identification.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system captures images at predetermined moments - before the user's hand crosses the inventory location plane and after it crosses. This preliminary timing of image capture ensures that the hand movement is clearly visible and detectable, reducing the precision requirements for image analysis compared to continuous or random sampling.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4148639B1Detecting item interaction and movement
Publication Date: 2026.02.18 AMAZON TECH INC
  • EP4148639B1 patent drawingFigure 1
  • EP4148639B1 patent drawingFigure 2
  • EP4148639B1 patent drawingFigure 3

AI summary

This disclosure describes a system for tracking removal or placement of items at inventory locations with a materials handling facility. In some instances, a user may remove an item from an inventory location and the inventory management system may detect that removal and update a user item list associated with the user to include an item identifier representative of the removed item. Likewise, if the user places an item at an inventory location, the inventory management system may detect that placement and update the user item list to remove an item identifier representative of the placed item.