Fixing Rotator Self-Cleaning via Toner Transfer Orientation

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Solution Overview

Problem

Image forming apparatuses face issues with toner offset and overheating, leading to residual toner and foreign substances adhering to the fixing rotator, which affects image quality and requires inefficient cleaning methods using specialized sheets or printed media.

Innovation Solution

The apparatus employs a cleaning method where a recording medium with a toner image is conveyed through a nip between a fixing rotator and a pressure rotator, creating a cleaning sheet with a different orientation to remove foreign substances from the fixing rotator, utilizing a temperature-controlled process to optimize cleaning performance without specialized cleaning sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a fixing rotator is used to fix toner images, then heat conduction efficiency is improved, but foreign substances and offset toner adhere to the fixing rotator surface

Engineering Contradiction:

Improveheat conduction efficiencyVSAvoidforeign substance adhesion

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful effect of the fixing rotator surface adhering to foreign substances and offset toner into a beneficial cleaning function. By intentionally allowing the fixing rotator to adhere toner during image formation, the accumulated toner is then used to clean the photoconductor drum surface, transforming a maintenance problem into a useful self-cleaning mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system enables the fixing rotator to perform dual functions: fixing toner images and self-cleaning the photoconductor drum. The toner that adheres to the fixing rotator during normal operation is subsequently transferred to clean the drum surface, allowing the system to maintain itself without additional cleaning components or specialized cleaning sheets.

Inventive Principle:

Principle #25Self-service

2Reliability

If specialized cleaning sheets or printed media are used to clean the fixing rotator, then cleaning performance is improved, but device complexity and operational costs increase

Engineering Contradiction:

Improvecleaning performanceVSAvoidcleaning system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the recording medium serve multiple functions: it acts as both the substrate for image formation and as the cleaning medium for the photoconductor drum. The same sheet that receives the toner image is used to clean the drum surface by transferring excess toner, eliminating the need for separate cleaning sheets or specialized cleaning materials.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The recording medium serves as an intermediary that transfers toner from the photoconductor drum to the fixing rotator and then back to clean the drum surface. This intermediary role allows the system to use ordinary recording media for cleaning purposes without requiring specialized cleaning components.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If the fixing rotator accumulates offset toner and foreign substances, then image quality deteriorates, but frequent cleaning increases loss of time

Engineering Contradiction:

Improveimage qualityVSAvoidcleaning time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The cleaning function is integrated into the continuous image formation process. As recording media continuously pass through the fixing device, they continuously clean the photoconductor drum surface by transferring toner, maintaining image quality without interrupting operation for separate cleaning cycles.

Inventive Principle:

Principle #20Continuity of useful 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

This method effectively removes toner stains and foreign substances from the fixing rotator, improving image quality and reducing operational costs by using standard recording media, while maintaining efficient cleaning performance.

Implementation Method 1

a heater that heats at least one of the first rotator and the second rotator

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

the cleaning image to remove a foreign substance from a surface of the first rotator

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11500314B2Image forming apparatus and cleaning method

Publication Date: 2022.11.15 RICOH CO LTD

AI summary

An image forming apparatus includes an image forming device that forms a toner image on a recording medium, a first rotator, and a second rotator that presses against the first rotator to form a nip therebetween. The first rotator conveys the recording medium bearing the toner image through the nip with a first orientation of the recording medium to fix the toner image on the recording medium to create a cleaning sheet bearing a cleaning image in a cleaning sheet creation mode. The first rotator conveys the cleaning sheet bearing the cleaning image through the nip with a second orientation of the cleaning sheet, that is different from the first orientation of the recording medium, such that the cleaning image is disposed opposite the first rotator to cause the cleaning image to remove a foreign substance from a surface of the first rotator in a cleaning mode.