Transfer Belt Control Prevents Triboelectrification Damage

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Solution Overview

Problem

In electrophotographic image forming apparatuses, the transfer belt contacting photoconductors during rotation can cause damage and contamination due to triboelectrification, and existing solutions do not effectively prevent this issue during mode switching and warm-up processes.

Innovation Solution

A control method where transfer rollers press the transfer belt after it has stopped rotating, and the rollers are controlled to release contact with photoconductors during mode switching and warm-up, ensuring the transfer belt does not contact photoconductors until rotation stops, thereby preventing triboelectrification and damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transfer belt rotates and contacts the photoconductors during operation, then image transfer function is achieved, but damage and contamination occur due to triboelectrification

Engineering Contradiction:
Improveprevention of damage and contaminationVSAvoidtriboelectrification damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The control method applies preliminary action by stopping the transfer belt rotation before engaging the transfer rollers to press the belt against the photoconductors. This sequence prevents triboelectrification from occurring in the first place, rather than attempting to mitigate its effects after damage or contamination has occurred. The system prepares the transfer mechanism in a damage-free state before contact is made.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent inverts the conventional operation sequence by stopping the transfer belt first and then pressing it against the photoconductors, rather than rotating the belt and making contact. This reversal of the normal operational sequence eliminates the harmful triboelectrification effect while still achieving the necessary transfer function.

Inventive Principle:
Principle #13The other way round (Inversion)

2Productivity

If the transfer rollers press the transfer belt during rotation, then transfer efficiency is improved, but the transfer belt and photoconductors may be damaged

Engineering Contradiction:
Improvetransfer efficiencyVSAvoidintegrity of transfer belt and photoconductors
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The system performs preliminary stopping of the transfer belt before applying pressure from the transfer rollers. This ensures that the pressing action occurs without rotational movement, eliminating the risk of damage while maintaining transfer efficiency. The sequence is prepared in advance to prevent harmful contact.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control method applies preliminary anti-action by stopping the transfer belt rotation before the transfer rollers engage. This counteracts the potential harmful effect of friction and damage that would occur if pressing happened during rotation, while still allowing the transfer function to be performed effectively.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If the transfer belt is stopped before pressing, then triboelectrification is prevented, but operation time increases due to waiting period

Engineering Contradiction:
Improveprevention of contaminationVSAvoidwaiting time for rotation to stop
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control method skips the unnecessary waiting period by immediately pressing the transfer belt against the photoconductors after stopping rotation. Since the belt is already stationary, there is no need to wait for rotation to cease, thus eliminating time loss while maintaining the benefit of preventing triboelectrification.

Inventive Principle:
Principle #21Skipping (Rushing through)

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 prevents damage to the transfer belt, rollers, and photoconductors, and avoids contamination by ensuring the transfer belt does not contact photoconductors until rotation has fully stopped, maintaining image quality and apparatus integrity.

Implementation Method 1

transfer rollers pressing the transfer belt to come into contact with the photoconductors so as to transfer the visible images on the photoconductors to the transfer belt

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

interrupting power transmitted to the transfer belt to cause the plurality of transfer rollers to press the transfer belt, standing by until rotation of the transfer belt is stopped, after interruption of the power

Methodology Applied
Scientific EffectRotational inertia: Inertia

Data Source

PatentEP2725426B1Image forming apparatus and control method thereof
Publication Date: 2021.08.25 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2725426B1 patent drawingFigure 1
  • EP2725426B1 patent drawingFigure 2
  • EP2725426B1 patent drawingFigure 3(A)~3(C)

AI summary

Disclosed herein are an image forming apparatus (100) and a control method thereof. The image forming apparatus includes a plurality of photoconductors (31), a transfer belt (51), a plurality of transfer rollers (54) arranged in parallel with the plurality of photoconductors, and a controller (202) rotating the transfer belt under the condition that at least one of the plurality of transfer rollers presses the transfer belt toward at least one of the plurality of photoconductors, interrupting power transmitted to the transfer belt to cause at least another of the plurality of transfer rollers to press the transfer belt toward at least another of the plurality of photoconductors, standing by until rotation of the transfer belt is stopped, after interruption of the power, and controlling the at least another of the plurality of transfer rollers so as to press the transfer belt toward the at least another of the plurality of photoconductors.