MR Sensor Resistor Configuration for Anti-Tapping Card Readers

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Solution Overview

Problem

Conventional card readers with false signal output circuits to prevent illegal data acquisition are expensive and require complex pre-head structures, making them costly and inefficient.

Innovation Solution

An MR sensor with a simplified structure using serially-connected resistors disposed at specific positions on the card reader to output a signal different from the actual magnetic data, allowing detection of magnetic data while preventing illegal acquisition and reducing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a false signal output circuit is provided inside the pre-head to prevent illegal acquisition of magnetic information, then security against tapping is improved, but the pre-head becomes expensive and complex

Engineering Contradiction:
Improvesecurity against tappingVSAvoidpre-head structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The false signal generation function is extracted from the pre-head and implemented separately using an MR sensor with a specific resistor configuration. This separates the security function from the main reading component, allowing the pre-head to remain simple while still providing anti-tapping protection through the independently configured MR sensor circuit.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The MR sensor uses a specific resistor configuration (first and second resistors serially connected at positions where first track is passed, third and fourth resistors serially connected at positions where second track is passed) with line-symmetric arrangements to generate a false signal that differs from actual magnetic data. This parameter-based approach creates security without adding complex circuitry to the pre-head.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a false signal output circuit is provided inside the pre-head to prevent illegal acquisition of magnetic information, then security against tapping is improved, but the cost increases

Engineering Contradiction:
Improvesecurity against tappingVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The false signal generation function is extracted from the pre-head and implemented separately using an MR sensor with a specific resistor configuration. This separates the security function from the main reading component, allowing the pre-head to remain simple while still providing anti-tapping protection through the independently configured MR sensor circuit.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The MR sensor with its resistor configuration provides a cost-effective security solution compared to modifying the expensive pre-head. By implementing the false signal generation in a separate, simpler component, the overall system cost is reduced while maintaining security functionality.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If a false signal output circuit is provided inside the pre-head to prevent illegal acquisition of magnetic information, then security against tapping is improved, but the pre-head structure becomes complex

Engineering Contradiction:
Improvesecurity against tappingVSAvoidpre-head structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The false signal generation function is extracted from the pre-head and implemented separately using an MR sensor with a specific resistor configuration. This separates the security function from the main reading component, allowing the pre-head to remain simple while still providing anti-tapping protection through the independently configured MR sensor circuit.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The MR sensor effectively detects magnetic data on a card while outputting a distinct signal, preventing illegal data acquisition and reducing the overall cost of the card reader system.

Implementation Method 1

an MR sensor for a card reader which is structured to detect whether or not magnetic data are recorded in a magnetic stripe of a card

Methodology Applied
Scientific EffectMagnetoresistive effect: Magnetoresistance

Data Source

PatentEP3190588B1Mr sensor and card reader
Publication Date: 2019.10.02 SANKYO SEIKI MFG CO LTD
  • EP3190588B1 patent drawingFigure 1~3
  • EP3190588B1 patent drawingFigure 4
  • EP3190588B1 patent drawingFigure 5(A)~5(B)

AI summary

Provided is an MR sensor for a card reader which can detect whether magnetic data is recorded on a magnetic stripe on a card when mounted in a card reader, and yet is able to prevent a criminal from illegally obtaining magnetic information, and with which the cost can be reduced. This MR sensor (10) is equipped with resistors (R1, R2) series-connected to each other and arranged at a position traversed by a first track (2c), and resistors (R3, R4) series-connected to each other and arranged at a position traversed by a second track (2d). The resistors (R2, R4) are connected to a power supply, and the resistors (R1, R3) are grounded. With this MR sensor (10), the difference in potential between a first center point (C1) between the series-connected resistors (R1 and R2) and a second center point (C2) between the series-connected resistors (R3 and R4) is the output.