Acoustic Paper Jam Detection Using Single Microphone

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Solution Overview

Problem

Existing methods for detecting paper jams in medium transport systems are either stressful to the paper at high speeds or require multiple localized sensors, leading to inefficiencies and loss of location-specific information.

Innovation Solution

A medium transport system using a single microphone to detect sound jams over a larger area, processing sound values by computing sums and avoiding complex signal processing methods, thereby improving detection accuracy and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a specialized paper transport cylinder is used to enhance diagnostic qualities, then paper wear detection is improved, but smooth paper transport at high speeds deteriorates

Engineering Contradiction:
Improvepaper wear detectionVSAvoidpaper transport speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The transport path is segmented into multiple zones with different cylinder profiles. The first transport cylinder has a first profile for normal transport, while a second transport cylinder has a second profile for enhanced diagnostic detection. This segmentation allows the system to switch between transport modes without compromising either speed or detection capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different transport cylinder profiles based on operational needs. During normal operation, the first cylinder profile maintains high-speed transport. During diagnostic phases, the second cylinder profile enhances paper wear detection. This dynamic adaptation resolves the contradiction between maintaining transport speed and enabling precise measurement.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple optical or mechanical sensors are used to detect paper passage, then detection coverage is improved, but device complexity increases

Engineering Contradiction:
Improvejam detection coverageVSAvoidsensor quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A single acoustic sensor is designed to perform multiple functions: detecting paper jams, measuring paper speed, and identifying paper wear. By making the sensor universal, the system achieves comprehensive monitoring coverage without multiplying the number of sensors, thus maintaining reliability while reducing device complexity.

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

Solution Approach 2:

The patent replaces multiple mechanical/optical sensors with a single acoustic sensor that detects paper condition through sound analysis. This substitution leverages acoustic field interactions instead of mechanical contact or optical detection, enabling one sensor to monitor the entire transport path and replace what would traditionally require multiple localized sensors.

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

3Measurement precision

If complex signal processing methods are used, then detection accuracy is improved, but computational resources and processing time increase

Engineering Contradiction:
Improvejam detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential acoustic features needed for jam detection from the raw sensor signal, rather than performing comprehensive spectral analysis. By taking out only the relevant information (amplitude thresholds and temporal patterns), the system maintains high detection accuracy while minimizing computational overhead and processing time.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system applies partial signal processing by using simple amplitude thresholding and temporal windowing instead of full spectral analysis. This partial action approach processes only the critical aspects of the acoustic signal needed for jam detection, achieving sufficient accuracy without the computational burden of exhaustive analysis methods.

Inventive Principle:
Principle #16Partial or excessive action

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 approach allows for accurate and reliable detection of paper jams using a single sensor, reducing computational resources and processing time while maintaining high accuracy across the entire transport path.

Implementation Method 1

A microphone senses the sound of the medium being conveyed along the medium transport path

Methodology Applied
Scientific EffectSound: Sound

Data Source

PatentEP3381846B1Audio detection of medium jam
Publication Date: 2019.08.28 KODAK ALARIS INC
  • EP3381846B1 patent drawingFigure 1
  • EP3381846B1 patent drawingFigure 2
  • EP3381846B1 patent drawingFigure 3

AI summary

A medium transport sytem for indicating a medium jam along a medium transport path and a system thereof are disclosed. The medium transport sytem for indicating a medium jam along a medium transport path comprising one or more rollers for use in conveying the medium along the medium transport path; a microphone for detecting the sound of the medium being conveyed and producing a signal representing the sound; a processor for producing sound values from the signal and computing a moving window sum responsive to the sound values; computing a high amplitude count responsive to the sound values; and computing a post roller sum responsive to the sound values; and indicating the medium jam responsive to the moving window sum, high amplitude count, or post roller sum.