Scale Guard Module Off-Weigh Platter Detection

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Solution Overview

Problem

Data readers equipped with scales often inaccurately measure weights when items overlap the edge of the scale or rest partially on the counter, leading to overcharging or undercharging customers due to the inability to detect such off-scale conditions effectively.

Innovation Solution

The implementation of a scale guard module that uses non-light-beam-based methods, such as ultrasonic, radiofrequency, or light beam technologies to detect whether an item extends between the weigh platter and another surface, comparing acquired data to reference data to determine if an item is off-scale, and alerting the user or disabling the weighing function if necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional scale is used without off-scale detection, then the device complexity is low, but measurement precision deteriorates due to inaccurate weight measurements when items overhang the scale

Engineering Contradiction:
Improveweight measurement accuracyVSAvoidscale system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary off-scale detection system consisting of light sources, light sensors, and control circuits that act as a mediator between the item being weighed and the weighing mechanism. This detection system monitors whether items are properly positioned on the scale before measurement, preventing inaccurate measurements without requiring fundamental changes to the scale's core weighing mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system performs preliminary detection of item positioning before the actual weighing process begins. The light sources and sensors continuously monitor the presence and position of items on the scale platform, and the control system prepares to either enable or disable weighing based on this preliminary assessment, ensuring measurement accuracy is maintained.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If off-scale detection systems are implemented, then measurement precision improves, but device complexity increases due to additional components

Engineering Contradiction:
Improveweight measurement accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent designs the off-scale detection system to serve multiple functions: detecting item presence, determining item position, controlling weighing enablement/disabling, and providing user feedback through displays or alarms. This multi-functionality reduces the need for separate systems for each function, thereby limiting the increase in overall device complexity while maintaining measurement precision.

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

Solution Approach 2:

The patent replaces complex mechanical detection methods with optical detection using light sources and light sensors. This substitution simplifies the detection mechanism while improving reliability and precision, as optical systems can detect item position accurately without physical contact or complex mechanical linkages.

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

3Difficulty of detecting and measuring

If light beam methods are used for off-scale detection, then detection capability improves, but the system becomes vulnerable to light interference and requires precise alignment

Engineering Contradiction:
Improveoff-scale detection capabilityVSAvoidlight interference and alignment sensitivity
Core Design Contradiction:
Difficulty of detecting and measuringVSObject-affected harmful factors

Solution Approach 1:

The patent uses optical patterns or codes placed on the scale platform that serve as reference copies for detection. The light sources illuminate these patterns, and the light sensors detect the reflected or transmitted light patterns to determine item position. This copying approach provides robust detection that is less sensitive to variations in lighting conditions or minor misalignments, as the system is detecting the presence or absence of the known pattern rather than relying on absolute light intensity.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution significantly reduces weighing errors by accurately detecting off-scale conditions, ensuring precise weight measurements and preventing customer overcharging or undercharging by alerting operators or halting the weighing process until items are properly positioned.

Implementation Method 1

transmit an ultrasonic wave toward the weigh platter edge

Methodology Applied
Scientific EffectUltrasonic wave transmission and reflection: Ultrasound

Implementation Method 2

transmit a radiofrequency signal and monitor a radiofrequency antenna for alterations of the radiofrequency signal

Methodology Applied
Scientific EffectRadiofrequency electromagnetic wave transmission: Radar

Implementation Method 3

transmit a light beam along the weigh platter edge

Methodology Applied
Scientific EffectLight beam transmission: Light

Data Source

PatentEP2373960B1Systems and methods for reducing weighing errors associated with partially off-scale items
Publication Date: 2019.02.06 DATALOGIC USA INC
  • EP2373960B1 patent drawingFigure 1
  • EP2373960B1 patent drawingFigure 2
  • EP2373960B1 patent drawingFigure 3~4

AI summary

Systems and methods are provided for reducing erroneous weighing of items (530, 830, 1230, 1710, 2400, 3011, 3211, 3264) by detecting items extending beyond a peripheral edge of a weigh platter (110, 3020, 3020a, 3120, 3240) associated with a data reader (180, 190). For example, in response to a weigh request a scale guard module (210) acquires data indicative of whether an item extends between the weigh platter and another surface (160), compares the acquired data to reference data, and based on the comparison, determines whether an item extends off the weigh platter and thus on to another surface. The scale guard module may utilize non-electromagnetic compression waves (520, 650), radio waves (820), a portion of a data reader's scan field to scan a set of patterns (1500, 1700, 1900, 2000) extending along at least one edge of the weigh platter, an imaging based scanner (2300) to capture an image of at least one edge (2330) of the weigh platter, a light beam extending along at least one edge of the weigh platter with or without a light guide (3030, 3130, 3190) disposed in the weigh platter, a plane of light (3263) extending along at least one edge of the weigh platter, or any combination thereof.