Coin Discrimination Sensor Segmentation for Eddy Current Interference

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Solution Overview

Problem

Conventional coin discrimination apparatuses struggle to accurately differentiate between genuine and counterfeit bimetallic coins due to interference between the ring and core sensors, leading to potential misidentification.

Innovation Solution

The coin discrimination apparatus employs a ring sensor with a smaller transmitting sensor diameter and a pot core type sensor to minimize eddy current interference, allowing for precise detection of magnetic properties of the ring and core parts by positioning sensors orthogonally to the conveyor direction, ensuring accurate discrimination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a ring sensor and core sensor are separately provided to detect magnetic properties of ring and core parts, then discrimination accuracy is improved, but sensor arrangement complexity increases

Engineering Contradiction:
Improvediscrimination accuracyVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor system is segmented into distinct ring sensors and core sensors positioned at separate locations. Ring sensors are arranged to detect only the ring part magnetic properties, while core sensors detect only the core part magnetic properties. This segmentation allows independent optimization of each sensor's detection zone and eliminates interference between sensors, thereby improving discrimination accuracy while maintaining manageable complexity through modular sensor design.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the transmitting sensor diameter is reduced to minimize eddy current interference, then detection precision is improved, but sensor size constraints are tightened

Engineering Contradiction:
Improvedetection precisionVSAvoidsensor diameter
Core Design Contradiction:
Measurement precisionVSArea of moving object

Solution Approach 1:

The transmitting sensor diameter is optimized by adjusting key parameters including the sensor diameter itself, the distance between transmitting and receiving sensors, and the operating frequency. By carefully selecting these parameters, the system achieves minimal eddy current interference while maintaining sufficient detection precision. The reduced sensor diameter is compensated by optimizing the sensor pair spacing and frequency characteristics, allowing the system to operate effectively within compact dimensional constraints.

Inventive Principle:
Principle #35Parameter changes

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 configuration effectively mitigates interference, enabling satisfactory detection of magnetic properties for both the ring and core parts, thereby enhancing the ability to distinguish genuine bimetallic coins from counterfeit ones.

Implementation Method 1

the eddy current generated in the ring part by the excitation of this transmitting sensor is impeded from reaching the core part

Methodology Applied
Scientific EffectEddy current: Eddy Currents

Implementation Method 2

the magnetic flux emitted from this transmitting sensor can be made to reach the ring part in the form of a small spot

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Data Source

PatentEP2098999B1Coin discrimination apparatus
Publication Date: 2016.01.13 LAUREL PRECISION MACHINES
  • EP2098999B1 patent drawingFigure 1A~2B
  • EP2098999B1 patent drawingFigure 3
  • EP2098999B1 patent drawingFigure 4~5B

AI summary

A coin discrimination apparatus according to the present invention which discriminates a bimetallic coin having a ring part, and a core part provided on an inner side of the ring part and composed of a different material from that of the ring part, includes: a conveyor which conveys the bimetallic coin; a ring sensor which is arranged at a position where only the ring part of the bimetallic coin conveyed by the conveyor transits, and which detects magnetic properties; and a core sensor which is arranged at a position where the core part of the bimetallic coin conveyed by the conveyor transit, and which detects magnetic properties.