Heating Roller Structure to Prevent Layer Peeling and Rust

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heating devices in image forming apparatuses face issues with peeling of the resistance heat generating layer due to rapid temperature changes and rusting, particularly at portions where the electrically insulating layer and resistance heat generating layer are provided on a metal roller substrate.

Innovation Solution

A heating device with an electrically insulating layer and resistance heat generating layer on the inner and/or outer peripheral surface of a metal roller substrate, without an additional anti-rust layer, and a divided heat generating pattern to adjust temperature distribution and prevent peeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an anti-rust layer is added to the metal roller substrate, then rust prevention is improved, but device complexity and layer peeling risk increase due to additional interfaces

Engineering Contradiction:
Improverust preventionVSAvoidlayer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention removes the anti-rust layer from the layer structure, using the metal roller substrate itself without additional anti-rust coating. This extraction of the unnecessary layer simplifies the structure while maintaining rust prevention through proper material selection of the metal substrate.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The metal roller substrate is designed to serve multiple functions simultaneously: it provides structural support, generates heat through the resistance layer, and prevents rust through its inherent material properties. This multi-functionality eliminates the need for separate anti-rust layers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Temperature

If heating is applied to the roller substrate, then heating performance is improved, but layer peeling occurs due to rapid temperature changes and thermal expansion

Engineering Contradiction:
Improveheating performanceVSAvoidlayer adhesion stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The invention changes the material parameters of the roller substrate, selecting metal materials with appropriate thermal expansion coefficients that match the resistance heat generating layer. This parameter matching prevents differential thermal expansion and subsequent peeling during rapid heating cycles.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure where the metal roller substrate and resistance heat generating layer are bonded together. The composite design ensures compatible thermal properties between layers, allowing them to expand and contract together without delamination during heating operations.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If the resistance heat generating layer is provided continuously, then heating uniformity is improved, but warm-up time increases

Engineering Contradiction:
Improvetemperature distribution uniformityVSAvoidwarm-up time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The invention divides the heating function into segments by providing multiple resistance heat generating layers at different positions on the roller substrate. This segmentation allows different regions to be heated independently and simultaneously, achieving uniform temperature distribution across the entire roller surface while reducing overall warm-up time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention implements periodic heating action by controlling the resistance heat generating layers to operate in alternating or sequential patterns. This periodic activation of different heating zones ensures comprehensive heating coverage while minimizing total heating time through efficient time-multiplexed operation.

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

Prevents peeling and rusting, reduces temperature differences, shortens warm-up time, and prevents abrasion, while maintaining effective heating performance.

Implementation Method 1

a resistance heat generating layer 533A, 533B which generates heat by resistance

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the roller substrate 531 is heated by both the resistance heat generating layer 533A, 533B and the external heat generating element 70

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4685572A1Heating device and image forming apparatus
Publication Date: 2026.01.28 FUJIFILM BUSINESS INNOVATION CORP
  • EP4685572A1 patent drawingFigure 1
  • EP4685572A1 patent drawingFigure 2
  • EP4685572A1 patent drawingFigure 3

AI summary

A heating device includes a heating roller that is rotated to heat a member to be heated, in which the heating roller is provided with at least an electrically insulating layer and a resistance heat generating layer that are provided in this order on one or both of an inner peripheral surface and an outer peripheral surface of a cylindrical roller substrate made of metal on which rust occurs, without an anti-rust layer.