Paper Conveying Jam Detection via Sound Frequency Analysis

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Solution Overview

Problem

Existing paper conveying apparatuses often mistakenly detect jams due to sounds from contact between the paper feed roller and paper, or from wrinkled paper, leading to incorrect jam detection.

Innovation Solution

The apparatus employs a sound detection system that differentiates between jam-causing sounds and special sounds, such as those from the paper feed roller's stick-slip vibration or wrinkled paper, by analyzing the frequency components and sharpness of the sound signals to accurately determine if a jam has occurred.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If jam detection is performed based on sound generated during paper conveyance, then the response time for detecting actual jams is improved, but false detection increases due to special sounds from rubber member contact and wrinkled paper

Engineering Contradiction:
Improvejam detection response timeVSAvoidjam detection accuracy
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies local quality by analyzing specific frequency components of the sound signal rather than treating all sounds uniformly. The sound detection unit identifies special sounds by examining their frequency characteristics, allowing the system to differentiate between genuine jam sounds and special sounds from rubber member contact or wrinkled paper based on their distinct frequency signatures

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of sound analysis from general sound detection to frequency-based discrimination. By transforming the sound detection approach to analyze frequency components, the system can distinguish between different types of sounds (jams versus special sounds) that have different frequency characteristics, thereby improving detection accuracy while maintaining rapid response

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the apparatus stops operation when a jam is detected within a predetermined time, then productivity is improved by quickly halting on actual jams, but false stopping occurs due to mistaken jam detection from special sounds

Engineering Contradiction:
Improveapparatus operational efficiencyVSAvoidjam detection reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements feedback by using the sound detection unit to continuously monitor the conveyance path and provide real-time information to the control unit. The control unit receives feedback about special sounds and adjusts its operation accordingly, preventing false stopping while maintaining rapid response to actual jams through continuous sound-based feedback monitoring

Inventive Principle:
Principle #23Feedback

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 effectively suppresses mistaken jam detection by identifying special sounds and determining that no jam has occurred when such sounds are present, thereby improving the accuracy of jam detection.

Implementation Method 1

a sound detection unit that detects a sound signal generated when a paper is conveyed

Methodology Applied
Scientific EffectSound: Sound

Data Source

PatentEP2708952B1Paper conveying apparatus, jam detection method, and computer program
Publication Date: 2020.03.25 PFU LTD
  • EP2708952B1 patent drawingFigure 1
  • EP2708952B1 patent drawingFigure 2
  • EP2708952B1 patent drawingFigure 3

AI summary

A paper conveying apparatus (100, 200) including a sound signal generator (141, 241) for generating a sound signal, a sound jam detector (153) for determining whether a jam has occurred based on the sound signal, a special sound detector (156) for determining whether a special sound has been generated based on a component of the sound signal, and a control module (151) for performing abnormal processing when the sound jam detector (153) determines that a jam has occurred and the special sound detector (156) determines that a special sound has not been generated, and determining that no jam has occurred and not performing the abnormal processing when the sound jam detector (153) determines that a jam has occurred and the special sound detector (156) determines that a special sound has been generated.