Image Forming Apparatus Cooling Layout for Fixing-Drum Heat Control

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Solution Overview

Problem

The downsizing of image forming apparatuses leads to the photosensitive drum unit being adversely affected by heat transfer from the fixing unit, necessitating improved heat management between these components.

Innovation Solution

An image forming apparatus design incorporating a fixing pressure release unit, a cooling fan, and a shifting mechanism that allows for vertical movement of the fixing unit, coupled with a cooling duct and partition plate to manage heat transfer and airflow between the drum and fixing units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the space between units is reduced for downsizing, then the apparatus size is reduced, but heat transfer from the fixing unit to the drum unit increases causing adverse effects

Engineering Contradiction:
Improveapparatus sizeVSAvoidheat transfer to drum unit
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

A heat insulating member is introduced as an intermediary substance between the fixing unit and the drum unit. This mediator blocks the harmful heat transfer path while allowing the units to be positioned close together, thus resolving the contradiction between downsizing and heat isolation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The internal space of the apparatus is segmented into distinct thermal zones using the heat insulating member and partition plate. This segmentation creates thermal boundaries that prevent heat propagation from the fixing unit to the drum unit, enabling compact arrangement while maintaining thermal independence.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If a heat insulating member is provided between the fixing unit and drum unit, then heat transfer is prevented, but the device complexity increases

Engineering Contradiction:
Improveheat transfer preventionVSAvoidstructure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The heat insulating member is designed to serve multiple functions: it provides thermal insulation, acts as a structural support element, and facilitates the positioning of the drum unit. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

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

Solution Approach 2:

The heat insulating member is integrated with the partition plate structure, combining thermal insulation and spatial separation functions into a single unified component. This merging approach prevents the need for separate insulation and partitioning elements, thus controlling device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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

Effectively reduces temperature loss in the fixing unit and drum unit by controlling airflow and heat transfer, enabling apparatus downsizing without compromising energy efficiency.

Implementation Method 1

The cooling fan produces a cooling air flow... The first cooling duct is provided on an outside of the lateral support plate and allows the air blown by the cooling fan to flow therethrough

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

a heat insulating member is provided between the fixing unit and the drum unit (a process cartridge) to insulate between the drum unit and the fixing unit, thus preventing heat transfer from the fixing unit to the drum unit

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP4603922A1Image forming apparatus
Publication Date: 2025.08.20 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4603922A1 patent drawingFigure 1
  • EP4603922A1 patent drawingFigure 2
  • EP4603922A1 patent drawingFigure 3

AI summary

An image forming apparatus (1) includes: a drum unit (120); a fixing unit (13) including a fixing member (131) and a pressing member (133); a fixing pressure release unit (14) disposed below the fixing unit (13); a body frame (2) including a lateral support plate (21L, 21R) and a partition plate (25); a cooling fan (22); a first cooling duct (23); and a shifting mechanism (200). The first cooling duct (23) is provided on an outside of the lateral support plate (21L, 21R). The lateral support plate (21L, 21R) is provided with an air outlet (24). The fixing pressure release unit (14) includes a nip pressure adjustment gear (134) and a rotary gear (142). The fixing unit (13) performs a switching behavior of switching a state of the fixing member (131) and the pressing member (133) between a pressed state and a released state by a rotary drive force supplied from the rotary gear (142) to the nip pressure adjustment gear (134). The shifting mechanism (200) shifts the fixing unit (13) vertically upward in conjunction with the switching behavior.