Paper Sheet Sorting White Reference Adjustment Near Side Walls

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Solution Overview

Problem

Existing paper sheet sorting devices face challenges in appropriately generating white reference data for correcting image data near the transport path's side walls, which affects shading correction and the ability to detect robbery ink on banknotes.

Innovation Solution

A paper sheet sorting device with a transport unit, light emitting and receiving units, and an adjusting unit that allows for the adjustment of white reference data specifically for pixels near the transport path's side walls, ensuring accurate shading correction and detection of robbery ink.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If paper sheets are stacked and stored before measurement, then the sheets become flat and measurement accuracy improves, but storage space is required and handling complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidhandling complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sheets are fed through the measurement device multiple times before actual measurement to pre-flatten them. This preliminary action eliminates the need for separate storage space while achieving the same flattening effect, thereby resolving the contradiction between measurement accuracy and handling complexity

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If multiple types of paper sheets are measured to create a comprehensive database, then adaptability improves, but the database becomes large and processing time increases

Engineering Contradiction:
ImproveadaptabilityVSAvoidprocessing time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The paper sheet database is segmented into multiple classification groups based on paper types. This segmentation allows the system to quickly locate and process only the relevant paper type during measurement, maintaining high adaptability while significantly reducing processing time by avoiding unnecessary data search and comparison

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If a large number of paper sheets are fed through the device to pre-flatten them, then measurement accuracy improves, but productivity decreases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The device implements periodic feeding of sheets through the measurement path at intervals, rather than continuous feeding. This periodic action allows sufficient time for each sheet to be properly flattened and measured while maintaining overall productivity, resolving the contradiction between measurement accuracy and productivity

Inventive Principle:
Principle #19Periodic 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

Enables appropriate shading correction and accurate detection of robbery ink on banknotes, even when they are near the transport path's side walls, while allowing for a downsized device.

Implementation Method 1

a measurement light source and a measurement light receiver arranged opposite to each other across the measurement region

Methodology Applied
Scientific EffectLight transmission and absorption: Absorption (EM radiation)

Data Source

PatentEP3951699B1Paper sheet sorting device, white reference data adjustment method, and program
Publication Date: 2026.05.06 JAPAN CASH MASCH CO LTD
  • EP3951699B1 patent drawingFigure 1(a)~1(b)
  • EP3951699B1 patent drawingFigure 2(a)~2(b)
  • EP3951699B1 patent drawingFigure 3(a)~3(c)

AI summary

To appropriately perform shading correction of an image of a paper sheet. The present invention includes a plurality of light receiving units that are placed at locations facing the other surface of a paper sheet being moved to receive detection light having passed through the paper sheet and that are arranged along a width direction orthogonal to a moving direction of the paper sheet, an image data generating unit that generates image data of a tone corresponding to the detection light having entered the light receiving units, and a white-reference-data storing unit that stores therein white reference data obtained by irradiating a white reference member to be used for shading correction of the image data with the detection light. The above configuration includes a movement restricting unit that is located at end parts in a width direction of a transport path and that forms side walls of the transport path, and an adjusting unit that adjusts the white reference data for shading correction of image data of the light receiving units to a predetermined value on a condition that locations in the width direction of the light receiving units are in a predetermined specific region.