Needlelike Electrode Charge Eliminator with Conductive Shielding

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Solution Overview

Problem

Existing electric charge eliminating devices using needlelike electrodes suffer from discharge unevenness, leading to poor cleaning and image defects, and require high voltage power sources to prevent discharge issues, which increases power consumption and space requirements.

Innovation Solution

An electric charge eliminating device with a needlelike electrode and a conductive shielding member, where the shielding member is arranged between the needlelike electrode and the image or recording medium carrier to suppress discharge unevenness by grounding excessive discharge current, and the structure includes a cover section to prevent excessive discharge current from reaching the shielding member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a needlelike electrode is used to eliminate electric charge, then the device structure is compact and ozone evolution is reduced, but discharge unevenness occurs between the tip portion and middle point of the electrode

Engineering Contradiction:
Improvedevice structure sizeVSAvoiddischarge uniformity
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The needlelike electrode is divided into multiple needlelike electrodes arranged in an array. Each electrode acts as an independent discharge point, and their collective effect provides uniform charge elimination across the entire surface of the image carrier, resolving the discharge unevenness issue while maintaining compact structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a conductive member with different conductivity regions: a first region with higher conductivity near the electrode tips to suppress excessive discharge, and a second region with lower conductivity farther away. This spatial variation in conductivity properties enables uniform discharge distribution across the electrode array.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a rib-shaped partition wall is added to prevent contact with sharp tip portions, then safety is improved, but discharge unevenness occurs more easily

Engineering Contradiction:
Improvecontact protectionVSAvoiddischarge uniformity
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The conductive member serves as an intermediary between the needlelike electrodes and the image carrier. It provides contact protection by preventing direct contact with sharp tips, while simultaneously controlling discharge uniformity through its spatially varying conductivity regions, thus resolving both safety and discharge uniformity requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the whole electric field is strengthened to prevent poor electric charge elimination, then charge elimination effectiveness is improved, but discharge at the tip portion becomes too strong causing discharge deterioration on the surface

Engineering Contradiction:
Improvecharge elimination effectivenessVSAvoidsurface discharge deterioration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The conductive member features spatially varying conductivity: a first region with higher conductivity near the electrode tips to suppress excessive discharge current and prevent surface deterioration, and a second region with lower conductivity farther away to maintain overall charge elimination effectiveness. This local differentiation resolves the contradiction between effective charge elimination and prevention of surface damage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the conductivity parameter of the conductive member across different spatial regions. By adjusting conductivity from high near the tips to low farther away, the system optimizes both discharge suppression at critical points and overall charge elimination performance, preventing surface deterioration while maintaining productivity.

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 effectively eliminates electric charges without increasing power source capacity or size, preventing discharge unevenness and image defects, while reducing power consumption and space requirements.

Implementation Method 1

a conductive shielding member arranged between the needlelike electrode and the image or recording medium carrier to suppress discharge unevenness by grounding excessive discharge current

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a needlelike electrode having a plurality of protruding sections which form a plurality of discontinuous discharge points

Methodology Applied
Scientific EffectElectrostatic discharge: Electrostatic Discharge

Data Source

PatentEP2386913B1Electric charge eliminating device and image forming apparatus equipped with the same
Publication Date: 2020.01.15 KONICA MINOLTA BUSINESS TECH INC
  • EP2386913B1 patent drawingFigure 1
  • EP2386913B1 patent drawingFigure 2
  • EP2386913B1 patent drawingFigure 3

AI summary

An electric charge eliminating device for eliminating electric charge on an image carrying member or on a recording medium carrying member which is incorporated in an image forming apparatus, comprises a needlelike electrode having a plurality of protruding sections which form a plurality of discontinuous discharge points; an insulating holder for holding the needlelike electrode; a discharging power source for applying an electric voltage to the needlelike electrode; and a conductive shielding member arranged between the needlelike electrode and the image carrying member or the recording medium carrying member.