Fixing Belt Temperature Control via Heat Diffusion Member

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Solution Overview

Problem

Conventional methods for detecting the temperature of a fixing belt in electrophotographic image forming apparatuses are insufficiently responsive to changes during the fixing operation, leading to inaccurate temperature control.

Innovation Solution

Incorporating a heat source within the fixing belt, a heat diffusion member to conduct heat evenly, and temperature detectors to monitor the heat diffusion member's temperature, allowing for more precise temperature control of the fixing belt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature is detected on the back side of the heater, then the detection structure is simple, but the response to temperature changes is insufficient

Engineering Contradiction:
Improvetemperature detection responsivenessVSAvoiddetection structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

A heat diffusion member is introduced as an intermediary between the heat source and the temperature detector. This member rapidly conducts heat from the heat source to the detection point, enabling the detector to sense temperature changes on the front side of the fixing belt with high responsiveness while keeping the detector itself positioned on the back side where it is easily accessible

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The temperature detection is achieved by measuring temperature at a different spatial location (back side of heater) than where the actual temperature control is needed (front side of fixing belt). The heat diffusion member bridges this spatial dimension, allowing indirect measurement with high fidelity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If a heat diffusion member is introduced to improve temperature detection responsiveness, then temperature control accuracy improves, but device complexity increases

Engineering Contradiction:
Improvetemperature control accuracyVSAvoidfixing device structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The heat diffusion member serves multiple functions simultaneously: it acts as a thermal conductor to rapidly transmit temperature changes, serves as a structural component of the fixing device, and provides a stable mounting surface for the temperature detector. This multi-functionality reduces the need for additional separate components

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 enhances the responsiveness of temperature change detection in the fixing belt, ensuring accurate and stable temperature control, which improves the fixing process and print quality.

Implementation Method 1

a heat diffusion member that conducts heat from the heat source to the fixing belt

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP4474916A1Fixing device and image forming apparatus
Publication Date: 2024.12.11 OKI ELECTRIC INDUSTRY CO LTD
  • EP4474916A1 patent drawingFigure 1
  • EP4474916A1 patent drawingFigure 2A~2B
  • EP4474916A1 patent drawingFigure 3

AI summary

A fixing section (18) includes: a fixing belt (120) that heats a developer image transferred to a recording medium to fix the developer image onto the recording medium; a heater (121) that generates heat, the heater (121) being disposed inside the fixing belt; a heat diffusion member (124) that conducts heat from the heater (121) to the fixing belt (120); and temperature sensors (122A, 122B, 122C) that detect a temperature of the heat diffusion member (124) to determine a temperature of the fixing belt (120).