Fixing Device Supporting Member Deflection Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional fixing devices face issues with heat efficiency and strength of the supporting member, leading to potential fixing failures during high-speed printing due to insufficient heat distribution and deflection of the nip forming member.

Innovation Solution

A fixing device with a rotatable endless belt, a nip forming member, a facing rotating body, and a supporting member with a rising portion that extends towards the inner surface of the belt, providing a section modulus of 200 mm^3 or higher to prevent deflection and ensure uniform contact pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of sheets passing through the fixing device per unit time is increased for high-speed processing, then productivity is improved, but the quantity of heat supplied becomes insufficient leading to fixing failure

Engineering Contradiction:

Improvenumber of sheets per unit timeVSAvoidheat quantity

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The fixing belt is divided into multiple heating zones with independent heating elements, allowing different sections to be heated to different temperatures. This segmentation enables the system to handle high-speed processing by providing sufficient heat quantity in each zone while maintaining overall productivity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the fixing belt are provided with different heating characteristics - the nip portion and surrounding areas have optimized heating to ensure adequate temperature distribution. This local quality adjustment ensures that even at high sheet speeds, each area receives the necessary heat quantity for proper fixing

Inventive Principle:

Principle #3Local quality

2Loss of energy

If a belt with small diameter is used to reduce heat dissipation area, then heat efficiency is improved, but the strength of the supporting member becomes insufficient causing deflection

Engineering Contradiction:

Improveheat dissipationVSAvoidsupporting member strength

Core Design Contradiction:

Loss of energyVSStrength

Solution Approach 1:

The supporting member is constructed using composite materials or optimized structural design that provides high strength-to-weight ratio. This allows the belt to maintain a compact diameter for reduced heat dissipation while the supporting member retains sufficient strength to prevent deflection under operating conditions

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The supporting member design incorporates dimensional optimization by extending in the abutting direction with adequate section modulus. This dimensional adjustment reduces heat dissipation surface area while maintaining structural strength through optimized geometry rather than simply increasing material quantity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If the section modulus of the supporting member is increased to prevent deflection, then reliability is improved, but the heat efficiency decreases due to increased heat dissipation area

Engineering Contradiction:

Improvefixing performanceVSAvoidheat dissipation

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The section modulus of the supporting member is optimized to a specific range that provides sufficient strength to prevent deflection and ensure reliable fixing performance, while controlling the dimensions to minimize heat dissipation area. This parameter optimization balances reliability requirements with energy efficiency

Inventive Principle:

Principle #35Parameter changes

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

The solution enhances heat efficiency, reduces the risk of fixing failures, and maintains consistent image quality by ensuring the supporting member's mechanical strength and preventing deflection, thus improving the overall performance of the fixing device.

Implementation Method 1

a heat source that directly heats up the fixing belt at a portion other than the nip portion

Methodology Applied

Scientific EffectDirect heating: Heating

Implementation Method 2

a toner image melts and permeates the recording sheet by the action of heat from a heat source provided inside the fixing roller

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 3

a toner image melts and permeates the recording sheet

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentUS9927748B2Fixing device and image forming apparatus

Publication Date: 2018.03.27 RICOH CO LTD

AI summary

A fixing device includes: a rotatable endless fixing belt; a nip forming member arranged inside the fixing belt; a facing rotating body that abuts the nip forming member via the fixing belt to form a nip portion with the fixing belt; a heat source that directly heats up the fixing belt at a portion other than the nip portion; and a supporting member that supports the nip forming member. The fixing device conveys a recording medium carrying an unfixed image to the nip portion to fix the unfixed image to the recording medium, and the supporting member includes a rising portion extending in an abutting direction of the facing rotating body against the fixing belt and having a tip close to an inner circumferential surface of the fixing belt, and is set to have a section modulus of 200 mm3 or higher.