Fixing Device Corona Charging Impurity Collection

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Solution Overview

Problem

In fixing devices, impurities from the medium can adhere to the charging means, leading to non-uniform electrical discharge and destabilization, potentially causing fixing failures due to the accumulation of toner and gases.

Innovation Solution

A fixing device with a second corona charging device positioned to collect impurities electrostatically, positioned upstream of the first corona charging device, which faces the heating body to maintain uniform discharge by absorbing or removing impurities before they reach the charging means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the charging means is positioned to face the heating body to electrically charge it, then electrostatic offset is restrained, but impurities from the medium adhere to the charging means causing non-uniform electrical discharge and destabilization

Engineering Contradiction:

Improvestability of electrical dischargeVSAvoidadhesion of impurities to charging means

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A collecting part is introduced as an intermediary component between the medium and the charging means. This collecting part absorbs or removes impurities generated from the medium before they can reach and adhere to the charging means, thereby maintaining uniform electrical discharge while preserving the charging function

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful impurities that would normally adhere to the charging means and cause discharge instability are instead directed to and absorbed by the collecting part. This converts the harmful effect of impurity generation into a beneficial collection process, protecting the charging means from contamination

Inventive Principle:

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

2Stability of the object's composition

If the charging means continuously operates to maintain uniform discharge, then electrostatic offset is prevented, but impurity accumulation leads to discharge non-uniformity over time

Engineering Contradiction:

Improveuniformity of electrical dischargeVSAvoidlong-term stability of charging means

Core Design Contradiction:

Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The collecting part is positioned upstream relative to the charging means in the rotation direction of the heating body, so it performs preliminary action by absorbing impurities before they reach the charging means. This prevents impurity accumulation on the charging means and maintains long-term discharge uniformity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback mechanism where the collecting part continuously monitors and removes impurities that would otherwise accumulate on the charging means. This continuous removal process maintains the charging means in a clean state, ensuring consistent discharge characteristics over extended operation periods

Inventive Principle:

Principle #23Feedback

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 stabilizes the discharge state for a longer period, reducing the risk of fixing failures by preventing impurities from adhering to the first corona charging device, especially when toner includes wax, and enhances the absorption capacity of impurities.

Implementation Method 1

a charging means (a corotron charger) electrically charging the surface of the rotating body with the same polarity as that of a toner

Methodology Applied

Scientific EffectCorona discharge: Corona Discharge

Implementation Method 2

the collecting part is positioned to face to a position at an upstream side with respect to a facing position on the heating body to the charging part and at a downstream side with respect to a forming position of the nip in a rotating direction of the heating body, and collects impurities caused by the medium passing the nip by absorbing or removing

Methodology Applied

Scientific EffectElectrostatic absorption: Electrostatic Induction

Data Source

PatentUS10175616B2Fixing device including collecting part collecting impurities of medium and image forming apparatus including this fixing device

Publication Date: 2019.01.08 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A fixing device includes a heating body, a pressuring body, a charging part and a collecting part. The heating body contacts with a medium having a toner image while rotating to heat the medium. The pressuring body forms a nip with the heating roller while rotating to pressure the medium passing through the nip with the heating body. The charging part is positioned to face to the heating body and electrically discharges to electrically charge the heating body with the same polarity as polarity of toner. The collecting part is positioned to face to a position at an upstream side with respect to a facing position on the heating body to the charging part and at a downstream side with respect to a forming position of the nip in a rotating direction of the heating body, and collects impurities caused by the medium passing the nip by absorbing or removing.