Image-Forming Fixing Web Winding Control with Variable-Resistor Feedback

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Solution Overview

Problem

Conventional web units in image forming apparatuses face inaccuracies in winding web amounts due to solenoid-based systems, leading to increased web consumption and reduced lifespan, as they fail to accurately control the rotation of the winding roller based on the outer diameter of the wound web.

Innovation Solution

The use of a variable resistor and winding motor system to detect the outer diameter of the wound web through a contact member, converting it into a resistance value, which is then used to control the rotation of the winding roller accurately, thereby minimizing errors and extending the web's lifespan.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a solenoid-based system is used to control the winding roller, then the device complexity is reduced, but the manufacturing precision of the winding amount deteriorates

Engineering Contradiction:
Improvecontrol system complexityVSAvoidwinding amount precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent replaces the solenoid-based mechanical control system with a motor-driven system equipped with a sensor feedback mechanism. The sensor detects the outer diameter of the wound web and converts it to a resistance value, which is then used by the motor control unit to precisely control the winding roller's rotation, thereby achieving high winding precision without complex mechanical linkages.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback control mechanism where a sensor continuously detects the outer diameter of the wound web on the winding roller. This detection value is converted to a resistance value and fed back to the motor control unit, which adjusts the winding roller's rotation in real-time to maintain precise winding control, compensating for variations in web thickness and tension.

Inventive Principle:
Principle #23Feedback

2Reliability

If the web is wound more to compensate for error, then the reliability of cleaning function is improved, but the loss of substance increases

Engineering Contradiction:
Improvecleaning function reliabilityVSAvoidweb consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The sensor-based feedback system accurately detects the actual winding amount by measuring the outer diameter of the wound web. This precise measurement eliminates the need for excessive web winding to compensate for errors, as the system can reliably control the winding to the exact required amount, thereby reducing web consumption while maintaining cleaning reliability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The replacement of the solenoid-based mechanical system with a motor-driven system featuring sensor feedback enables precise control of the winding amount. This eliminates the large errors inherent in mechanical gear-based systems, allowing the web to be wound only to the necessary extent for reliable cleaning without excessive consumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If a lever and gear system is used in the solenoid mechanism, then the ease of manufacture is improved, but the manufacturing precision of the winding amount deteriorates

Engineering Contradiction:
Improvemechanical system assemblyVSAvoidwinding amount precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces the lever and gear mechanical transmission system with a motor-driven system that uses sensor feedback for control. This eliminates the accumulation of manufacturing tolerances and play inherent in mechanical linkages, achieving high winding precision through electronic control while simplifying the overall system structure by removing complex mechanical components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 allows for precise control of the web winding, reducing consumption and prolonging the web's life by minimizing errors in the winding amount, thus enhancing the efficiency and reliability of the image forming process.

Implementation Method 1

converting it into a resistance value, which is then used to control the rotation of the winding roller

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP4141568B1Image forming apparatus
Publication Date: 2025.07.02 CANON KK
  • EP4141568B1 patent drawingFigure 1
  • EP4141568B1 patent drawingFigure 2
  • EP4141568B1 patent drawingFigure 3

AI summary

An image forming apparatus includes a heating rotary member that heats toner born on a recording material, and a pressure rotary member that pressurizes the heating rotary member. These rotary members form a fixing nip portion and fix a toner image to the recording material at the fixing nip portion while nipping and conveying the recording material. The apparatus further includes a web that collects toner adhering to a surface of the heating rotary member, a winding roller that winds the web, a motor that rotates the winding roller, a contact member that makes contact with an outer surface of the wound web and moves based on a position of the outer surface, a variable resistor that changes a resistance value depending on a position of the contact member, and a control unit that controls a rotation amount of the motor based on the resistance value.