Weigh Scale Perimeter Monitoring Using Light Guide Detection
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Solution Overview
Problem
Existing scanner-scale systems face inaccuracies in weighing due to items extending beyond the scale perimeter, leading to incorrect weight measurements and potential revenue loss, as previous solutions require precise optical alignment and are prone to misalignment.
Innovation Solution
A system with a light source and detector integrated into the scanner-scale housing, utilizing a light guide within the weigh platter to route the light beam to the detector, reducing the need for precise alignment and preventing misalignment, and employing divergent light beams that form a light curtain to detect items encroaching on the scale perimeter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mirrors are used to direct the light beam around the perimeter of the weigh platter, then the light path can be routed around the scale surface, but the system requires precise optical alignment and is subject to misalignment from impact
Solution Approach 1:
The patent introduces light guides as intermediary elements that replace the direct optical path using mirrors. The light guides are disposed within the weigh platter structure itself, acting as mediators that channel light from the light source around the perimeter to the detector without requiring external mirrors. This eliminates the alignment precision requirements while maintaining the light path routing function.
Solution Approach 2:
The light guides are nested within the weigh platter structure, with the light guides being disposed in the weigh platter according to the patent. This nesting integrates the optical routing function directly into the existing platter structure, eliminating separate alignment-sensitive components like mirrors while achieving the same light path routing objective.
2Reliability
If a light beam path is positioned above the weigh platter surface, then off-scale items can be detected, but items being scanned may interfere with the movement of the light beam and cause misalignment
Solution Approach 1:
The patent transitions the light detection system from a vertical dimension (above the platter surface) to a horizontal dimension (within the platter structure). By disposing light guides within the weigh platter and routing light along the perimeter at the platter level, the system eliminates vertical interference from scanned items while maintaining detection capability through the light curtain formed by the light guides.
3Ease of operation
If the weigh platter is flush mounted with the checkout counter, then the scale integrates with the counter surface, but items can extend beyond the scale perimeter and contact the counter resulting in inaccurate weighing
Solution Approach 1:
The light guides act as intermediary elements that detect the presence of off-scale items before they contact the counter. By routing light through the platter perimeter and detecting interruptions in the light path, the system identifies items extending beyond the scale boundary, allowing for correction or rejection of inaccurate weight measurements while maintaining flush mounting integration.
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 effectively reduces erroneous weighing by alerting operators to off-scale items, ensuring accurate weight measurements without the alignment issues of previous systems, thereby preventing revenue loss and improving operational reliability.
Implementation Method 1
a light guide disposed in the weigh platter for routing the light beam to the detector
Implementation Method 2
the detector is operative for detecting an interruption of the light beam due to an item encroaching upon or overhanging an edge of the weigh platter
Data Source
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AI summary
Systems and methods for reducing erroneous weighing of items such as by detecting items (11) extending beyond a periphery of a weigh platter (20, 120, 170, 240) whereby in one configuration, the system employs a light guide (30, 320) for routing a light beam to a detector (40,140) operative to detect interruption of the beam due to an item encroaching upon or overhanging an edge of the platter. In another configuration, the scale includes a perimeter gap (252, 257) between the platter outer edge and scanner housing frame or checkout counter, a light beam directed angularly upward through the gap is partially obstructed by the frame and platter whereby light exits the gap forming a light plane, wherein an object placed on the platter extending across the gap intersects the light plane thus scattering light rays, some of which are sensed by a detector (280). Various indicators (295, 297) for alerting the operator of off-scale detection are also described.