Document Platen Overlap Structure for Accurate Edge Detection

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Solution Overview

Problem

Existing document reading devices struggle to accurately detect the edge of a document due to non-overlapping first and second placing portions in the vertical direction, leading to potential failure in detection by the detector.

Innovation Solution

A document reading device with a placing portion comprising a first and second placing portion, where the end of the first placing portion extends beyond the second, allowing edge detection using color or luminance differences, and a detector that utilizes these differences to identify document edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single placing portion is used, then the structure is simple, but the detector fails to accurately detect the document edge due to insufficient color or luminance difference

Engineering Contradiction:
Improvedocument edge detection accuracyVSAvoidplacing portion structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The placing portion is divided into multiple segments (first placing portion and second placing portion) with different colors or luminance levels. This segmentation creates sufficient contrast between the placing surface and the document, enabling the detector to accurately identify the document edge by detecting the boundary between different placing portions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the placing portion are assigned different local qualities (colors or luminance levels). The first placing portion has one color/luminance characteristic while the second placing portion has another, creating a visual gradient that helps the detector distinguish the document boundary from the placing surface.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If multiple placing portions with different colors are used, then the document edge detection accuracy is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvedocument edge detection accuracyVSAvoidplacing portion manufacturing
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The placing portion is segmented into multiple manufacturable units with distinct color or luminance properties. Each segment can be manufactured separately using standard manufacturing processes, and then assembled together to form the complete multi-colored placing surface, balancing detection accuracy with manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

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

Enhances edge detection accuracy by leveraging color or luminance differences, reducing component count, and enabling compact design with increased load capacity and ease of document handling.

Implementation Method 1

a detector that detects an edge of the document that is placed on the placing surface by using a color difference or a luminance difference between the placing surface and the document

Methodology Applied
Scientific EffectColor difference detection:

Implementation Method 2

a detector that detects an edge of the document that is placed on the placing surface by using a color difference or a luminance difference between the placing surface and the document

Methodology Applied
Scientific EffectLuminance difference detection:

Data Source

PatentEP4141554B1Document reading device and image forming apparatus
Publication Date: 2026.05.20 FUJIFILM BUSINESS INNOVATION CORP
  • EP4141554B1 patent drawingFigure 1-1
  • EP4141554B1 patent drawingFigure 1-2
  • EP4141554B1 patent drawingFigure 1-3

AI summary

A document reading device includes an imaging unit that images a document, a placing portion that includes a first placing portion and a second placing portion and that has a placing surface on which the document is placed, the placing surface being formed by the first placing portion and the second placing portion, and a detector that detects an edge of the document that is placed on the placing surface by using a color difference or a luminance difference between the placing surface and the document. An end portion of the first placing portion adjacent to the second placing portion extends toward the second placing portion beyond an end portion of the second placing portion adjacent to the first placing portion.