Sheet Thickness Detection Using Multi-Frequency Resonance Circuits

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing paper sheet processing apparatuses face challenges in accurately detecting the thickness of sheets, particularly when reinforcing materials are applied, due to interference between multiple coil patterns in thickness detecting devices, leading to inaccurate thickness measurements.

Innovation Solution

The apparatus employs a thickness detecting unit with a configuration of multiple resonance circuits and displacement members, where each resonance circuit has a unique resonance frequency, and a calculation unit processes the impedance to determine the thickness of the paper sheet, minimizing interference and enhancing detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple planar coil patterns are arranged closely on a planar board to detect the thickness of the entire surface of a paper sheet, then the detection coverage is improved, but the oscillation circuits interfere with each other due to pull-in phenomenon or coupling phenomenon, resulting in decreased measurement precision

Engineering Contradiction:
Improvedetection coverage areaVSAvoidthickness measurement accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent divides the detection system into multiple independent resonance circuits, each with its own unique resonance frequency. By segmenting the detection function across multiple frequencies rather than using a single frequency for all coils, the system可以避免相互干扰 while maintaining comprehensive coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the frequency parameter of each resonance circuit to be unique. By assigning different resonance frequencies to different coil patterns, the system eliminates coupling phenomena and pull-in effects that occur when coils operate at the same frequency, thereby maintaining measurement precision across the entire detection area.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple resonance circuits are used to detect thickness across the entire surface, then the detection accuracy is improved, but the device complexity increases due to multiple oscillation circuits

Engineering Contradiction:
Improvethickness detection accuracyVSAvoidnumber of oscillation circuits
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes each resonance circuit multi-functional by designing them to operate independently at different frequencies within the same detection system. Each resonance circuit can detect thickness at its specific location while also contributing to the overall surface coverage, eliminating the need for separate systems for each function.

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

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 allows for precise detection of paper sheet thickness, even with reinforcing materials, by suppressing interference between resonance circuits and improving the accuracy of thickness measurements.

Implementation Method 1

The thickness detecting device includes, for example, a noncontact displacement sensor having a coil and an oscillation circuit. The thickness detecting device detects the distance between the coil and the measuring target by detecting a variation in oscillation frequency or inductance of the oscillation circuit which varies depending on the distance between the coil and the measuring target.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The apparatus employs a thickness detecting unit with a configuration of multiple resonance circuits and displacement members, where each resonance circuit has a unique resonance frequency, and a calculation unit processes the impedance to determine the thickness of the paper sheet

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3141502B1Sheet processing apparatus and method including an apparatus and a method for detecting sheet thickness
Publication Date: 2018.06.13 KK TOSHIBA
  • EP3141502B1 patent drawingFigure 1
  • EP3141502B1 patent drawingFigure 2
  • EP3141502B1 patent drawingFigure 3

AI summary

A sheet (P) processing apparatus (1) and method, the apparatus comprising a thickness detecting device (100), the thickness detecting device including: a plurality of conductive displacement members (220) configured to be displaced depending on the thickness of the sheet (P); a plurality of resonance circuits (210) that are disposed to correspond to the plurality of displacement members (220), each including a coil (204) facing the corresponding displacement member (220) and a capacitor (208), where neighboring resonance circuits resonate at different resonance frequencies; and means for detecting the distance between the displacement members and their associated resonance circuits based on impedance values of the plurality of resonance circuits and the plurality of displacement members; and a calculation unit (240) that calculates a thickness of the sheet based on the distance values, and therefore on impedance values of the plurality of resonance circuits and the plurality of displacement members.