Document Feeder Shape Sensing to Prevent Bound Sheet Jams

Solution Overview

Problem

Conventional image reading apparatuses face issues with document sheets becoming wrinkled or torn when bound by staples or clips, leading to paper jams, and fail to provide user-friendly solutions for reading such documents.

Innovation Solution

The apparatus includes a distance measurement sensor to detect unusual document shapes, suspends conveyance upon detection, and allows user-controlled re-conveyance for reading, without suspending conveyance based on initial measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the ADF separates and conveys document sheets one by one, then reading efficiency is improved, but bound documents may become wrinkled or torn

Engineering Contradiction:

Improvereading efficiencyVSAvoiddocument damage

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection of bound portions before conveyance begins. When a bound document is detected, the system proactively suspends the conveyance operation before the document can be damaged, allowing the user to manually handle the bound document appropriately.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the document conveyance process and provides feedback to the control unit. When a bound portion is detected during conveyance, the system adjusts its operation in real-time by suspending conveyance, creating a closed-loop control system that prevents document damage while maintaining reading efficiency for normal documents.

Inventive Principle:

Principle #23Feedback

2Reliability

If the system detects bound documents by measuring height change during conveyance, then bound document detection is achieved, but documents that are already bent or wrinkled may be erroneously detected as bound

Engineering Contradiction:

Improvebound document detection accuracyVSAvoiddetection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of bound portions before conveyance begins. When a bound document is detected, the system proactively suspends the conveyance operation before the document can be damaged, allowing the user to manually handle the bound document appropriately.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors the document conveyance process and provides feedback to the control unit. When a bound portion is detected during conveyance, the system adjusts its operation in real-time by suspending conveyance, creating a closed-loop control system that prevents document damage while maintaining reading efficiency for normal documents.

Inventive Principle:

Principle #23Feedback

3Object-affected harmful factors

If the system suspends conveyance when bound documents are detected, then document damage is prevented, but reading operations are interrupted and user-friendly solutions are not provided

Engineering Contradiction:

Improvedocument damage preventionVSAvoiduser convenience

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The system continuously monitors the document conveyance process and provides feedback to the control unit. When a bound portion is detected during conveyance, the system adjusts its operation in real-time by suspending conveyance, creating a closed-loop control system that prevents document damage while maintaining reading efficiency for normal documents.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system provides self-service by automatically detecting bound documents and suspending conveyance without requiring user intervention. The system independently determines when to pause operation, reducing the burden on users while still preventing document damage.

Inventive Principle:

Principle #25Self-service

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

Prevents document damage and jams by allowing user-controlled re-conveyance of bound documents, ensuring seamless reading operations.

Implementation Method 1

a measurement unit configured to measure a distance from an upper portion of a sheet feeding port for the document to an upper surface of the document

Methodology Applied

Scientific EffectDistance measurement:

Data Source

PatentUS12506838B2Image reading apparatus having sensor for detecting shape of fed documents, control method for controlling image reading apparatus, and storage medium having stored therein control method

Publication Date: 2025.12.23 CANON KK

AI summary

An image reading apparatus includes a conveying unit configured to convey a document, a reading unit configured to read an image on the conveyed document, a measurement unit configured to measure a distance from an upper portion of a sheet feeding port for the document to an upper surface of the document, and a control unit configured to, according to the distance measured by the measurement unit, suspend the conveyance of the document by the conveying unit. According to a user operation for reading again the document of which the reading is suspended by the control unit, the conveying unit conveys the document and the reading unit reads the image on the document, and while the document of which the conveyance is suspended is conveyed again, the control unit does not suspend the conveyance of the document based on the distance measured by the measurement unit.