Endless Belt Cutout for Direct Roller Heating

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Solution Overview

Problem

Existing imaging apparatuses using electrophotographic systems face inefficiencies in heating and cooling processes, particularly in achieving rapid pre-heating of pressure rollers and maintaining energy efficiency, which affects the production of glossy print outputs.

Innovation Solution

The implementation of a fixing device with an endless belt featuring a cutout allows direct contact between the heat roller and pressure roller during warm-up, enabling uniform heating of the pressure roller and reducing energy consumption, while a cooling device cools the re-melted toner image in overlay with the endless belt to impart glossiness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the heat roller heats the pressure roller through the endless belt during warm-up, then the pressure roller can be heated uniformly, but the heating time is extended and power consumption increases

Engineering Contradiction:

Improvepressure roller surface temperatureVSAvoidwarm-up time

Core Design Contradiction:

TemperatureVSLoss of time

Solution Approach 1:

The endless belt is extracted from the heating path during warm-up by utilizing its cutout portion, allowing the heat roller to directly heat the pressure roller without the belt's thermal interference, thereby reducing warm-up time while maintaining uniform heating through direct contact

Inventive Principle:

Principle #2Taking out (Extraction)

2Temperature

If the heat roller heats the pressure roller through the endless belt during warm-up, then the heating process is continuous, but power consumption increases

Engineering Contradiction:

Improvepressure roller surface temperatureVSAvoidpower consumption

Core Design Contradiction:

TemperatureVSUse of energy by stationary object

Solution Approach 1:

The endless belt is extracted from the thermal path during warm-up operations by positioning its cutout between the heat roller and pressure roller, eliminating unnecessary thermal mass that must be heated, thereby reducing power consumption while achieving the required pressure roller temperature

Inventive Principle:

Principle #2Taking out (Extraction)

3Loss of time

If the cutout of the endless belt is positioned at the fixing nip during warm-up, then direct heating contact is enabled, but the belt cannot perform its normal fixing function

Engineering Contradiction:

Improvewarm-up timeVSAvoidfixing function

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The system dynamically switches between two operational modes: during warm-up, the cutout is positioned at the fixing nip to enable direct heating contact; during normal operation, the belt is positioned to cover the fixing nip for proper fixing function, allowing the system to adapt to different operational requirements

Inventive Principle:

Principle #15Dynamics

4Temperature

If the endless belt is used for cooling the toner image, then glossy finish is achieved, but the belt structure becomes more complex

Engineering Contradiction:

Improvetoner image temperatureVSAvoidendless belt structure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The endless belt with cutout serves multiple functions: it enables direct heating contact during warm-up by positioning the cutout at the fixing nip, performs normal fixing operations when positioned differently, and cools the toner image through its contact with the discharged paper, eliminating the need for separate cooling structure

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 solution shortens the time to reach the predetermined temperature of the pressure roller, reduces power consumption, and effectively produces glossy print outputs by uniformly heating the pressure roller and cooling the re-melted toner image.

Implementation Method 1

the heat roller rotates in direct contact with the pressure roller through the cutout... to evenly heat the pressure roller

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a cooling device to cool the endless belt moving from the heat roller to the tension roller

Methodology Applied

Scientific EffectCooling: Cooling

Data Source

PatentUS11287768B2Fixing device including endless belt with a cutout

Publication Date: 2022.03.29 HEWLETT PACKARD DEVELOPMENT COMPANY LP

AI summary

A fixing device includes an endless belt to rotate about rollers, including a heat roller. A pressure roller presses the endless belt against the heat roller. A cooling device is located adjacent a portion of the endless belt, that moves from the heat roller to the tension roller. The endless belt has a cutout, and the heat roller directly contacts the pressure roller through the cutout, when the cutout of the endless belt is located between the pressure roller and the heat roller.