Fixing Device Electrode Projections for Charged Sheet Stability

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Solution Overview

Problem

Existing fixing devices face challenges in stably providing fixing solution to sheets due to electrostatic repulsive forces between misted fixing solution and electrically charged sheets, leading to inefficient fixation of toner images.

Innovation Solution

The fixing device incorporates a nozzle unit and an opposite electrode with strategically designed first projections that concentrate electrostatic forces, creating a strong electric field to attract and securely direct the fixing solution onto the sheet, even when the sheet is electrically charged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a voltage is applied to the opposite electrode to attract fixing solution, then the fixing solution can be provided to the sheet, but electrostatic repulsive force is generated between misted fixing solution and the electrically charged sheet, making it difficult to stably provide the fixing solution

Engineering Contradiction:
Improvestability of fixing solution provisionVSAvoidelectrostatic repulsive force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The opposite electrode is divided into multiple electrode sections along the sheet conveying direction, with each section independently controllable. This segmentation allows selective application of voltage to different regions, enabling precise control of electrostatic attraction while minimizing overall repulsive effects on the charged sheet.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The voltage application to the opposite electrode is made dynamic and adjustable. By controlling the timing, magnitude, and distribution of voltage across different electrode sections, the system can adapt to varying electrostatic conditions of the sheet, optimizing attraction of fixing solution while compensating for repulsive forces.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the fixing solution is sprayed onto the electrically charged sheet, then the sheet receives the fixing solution, but the electrostatic repulsive force prevents effective attraction and stable fixation

Engineering Contradiction:
Improveamount of fixing solution providedVSAvoidelectrostatic repulsive force
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

Different electrode sections are assigned different voltage characteristics tailored to local requirements. By adjusting voltage magnitude and timing for each electrode section, the system creates localized electric field conditions that optimize fixing solution attraction in specific regions while accounting for local sheet charge distribution.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically changes electrical parameters (voltage magnitude, timing, distribution) of the opposite electrode to overcome electrostatic repulsion. By adjusting these parameters, the attractive force on fixing solution mist can be optimized despite the repulsive force from the charged sheet.

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

This configuration ensures stable attraction and application of the fixing solution, effectively overcoming electrostatic repulsion and ensuring reliable fixation of toner images on sheets.

Implementation Method 1

A voltage is applied to the opposite electrode... an electrostatic repulsive force is generated between the mists of the fixing solution and the sheet... strategically designed first projections that concentrate electrostatic forces, creating a strong electric field to attract and securely direct the fixing solution onto the sheet

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP3951503B1Fixing device
Publication Date: 2024.11.06 BROTHER KOGYO KK
  • EP3951503B1 patent drawingFigure 1
  • EP3951503B1 patent drawingFigure 2
  • EP3951503B1 patent drawingFigure 3A~3B

AI summary

Provided is a fixing device capable of stably imparting a fixing solution sprayed from each of a plurality of nozzles to a sheet even when the sheet is electrically charged. A fixing device 9 includes a nozzle unit 9A and an opposite electrode 9B. The nozzle unit 9A sprays a fixing solution to a sheet S on which a toner image is formed. The opposite electrode 9B is located at an interval from the nozzle unit 9A. The opposite electrode 9B is applied with a voltage. The opposite electrode 9B has a first flat plate 31 and a plurality of first projections 32. The first flat plate 31 extends in a first direction. The plurality of first projections 32 extends from the first flat plate 31 in a second direction that is a direction facing from the opposite electrode 9B toward the nozzle unit 9A. The plurality of first projections 32 are aligned in the first direction.