Fixing Belt Heater with Insulating Member for Image Forming

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Solution Overview

Problem

Conventional fixing devices for image forming apparatuses using electrophotography suffer from heat energy loss and inefficient energy usage, leading to prolonged warm-up times and increased energy consumption during standby modes.

Innovation Solution

A fixing device with a fixing roller, a curved plate-shaped heater, and an endless fixing belt, where the heating member is positioned close to the fixing roller with an opening along the axial direction to cover the pressing part side, and an insulating member is used to minimize heat radiation and maximize heat transfer to the fixing belt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a fixing belt is used instead of a fixing roller, then the heat capacity is reduced and warm-up time is shortened, but heat radiation loss increases causing fixing failure

Engineering Contradiction:

Improvewarm-up timeVSAvoidheat radiation loss

Core Design Contradiction:

Loss of timeVSLoss of energy

Solution Approach 1:

An insulating member is introduced as an intermediary between the heating member and the external environment. This insulating member covers the heating member and reduces heat radiation loss to the surroundings, thereby preventing fixing failure while maintaining the low heat capacity advantage of the fixing belt configuration.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating member is selectively applied to specific areas where heat radiation loss occurs, rather than uniformly insulating the entire fixing device. This localized insulation approach reduces heat loss at critical points while maintaining efficient heat transfer to the fixing belt where needed.

Inventive Principle:

Principle #3Local quality

2Temperature

If the heating member covers the entire fixing roller, then heat transfer is maximized, but heat radiation loss to other areas increases

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidheat radiation loss

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The heating member is divided into multiple independent heating sections along the circumferential direction of the fixing roller. Each heating section can be independently controlled and positioned to provide heat only where needed, rather than uniformly heating the entire roller circumference. This segmentation allows heat to be concentrated on the fixing belt contact area while reducing radiation loss to other areas.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The heating member provides non-uniform heat distribution with higher heating intensity at locations where the fixing belt contacts the roller, and reduced or no heating at areas where heat radiation would be wasted. This localized heating approach maximizes heat transfer efficiency to the fixing belt while minimizing energy loss to the surrounding environment.

Inventive Principle:

Principle #3Local quality

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 reduces heat energy loss, enables stable toner image fixation, and improves energy efficiency by allowing for shorter warm-up times and reduced energy consumption.

Implementation Method 1

a heating member as a heat generator having a curved surface; and an endless fixing belt wound between the fixing roller and the outer peripheral side of the heating member

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

since heat radiation from the surface of the fixing belt in the other area than where the curved plate-shaped heater exists is not negligible, the fixing device of Patent Document 1 has the problem of loss of heat energy

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentUS8706015B2Fixing device including fixing belt and image forming apparatus using the same

Publication Date: 2014.04.22 SHARP KK

AI summary

An image forming apparatus includes photoreceptor drums, a charger, an exposure unit, a developing unit, an intermediate transfer belt and a fixing unit for fixing a toner image to a recording medium. The fixing unit includes a fixing part and a pressing part. The fixing part has a fixing roller, a heating member and a fixing belt. The pressing part has a pressing roller. The heating member is arranged close to, and so as to cover, the outer peripheral side of the fixing roller, and formed with an opening. Both edges of the opening extending along the axial direction of the fixing roller, are positioned closer to the pressing part side than the center axis of the fixing roller is.