Image Forming Apparatus Support Unit Toner Attachment

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Solution Overview

Problem

In image forming apparatuses, the support unit for the recording medium may experience misregistration due to shocks during transfer unit contact, and direct conductivity between the support unit and transfer unit can lead to unwanted toner attachment due to the electric field.

Innovation Solution

The use of a jig or support unit that is electrically conductive and connected to ground, combined with a non-conductive layer or controlled voltage application, prevents direct conductivity between the support unit and transfer unit, reducing toner attachment and minimizing shocks during image transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the support unit is made electrically conductive and connected to ground, then misregistration due to shock is reduced, but particles such as toner are undesirably attached to the support unit by electric field

Engineering Contradiction:
Improvemisregistration preventionVSAvoidtoner attachment to support unit
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a non-conductive layer as an intermediary between the conductive support unit and the transfer unit. This intermediate layer prevents direct electrical contact, thereby eliminating the harmful effect of toner particles being attracted to the support unit by the electric field, while still allowing the support unit to provide mechanical support and shock absorption functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If the support unit directly contacts the transfer unit, then particle attachment is reduced, but misregistration occurs due to shock during contact

Engineering Contradiction:
Improvetoner attachment reductionVSAvoidimage registration accuracy
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The non-conductive layer serves as a mediator that allows controlled interaction between the support unit and transfer unit. It provides electrical isolation to prevent toner attachment while maintaining mechanical contact for stable image transfer, thus resolving the contradiction between preventing particle attachment and ensuring registration accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the electrical conductivity parameter of the support unit interface by introducing a non-conductive layer. This parameter change transforms the interface from electrically conductive to electrically insulating, thereby preventing toner attachment while maintaining the mechanical support function needed for precise registration.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If voltage is continuously applied to the transfer unit, then image transfer efficiency is improved, but particles are attracted to the support unit

Engineering Contradiction:
Improveimage transfer efficiencyVSAvoidtoner attachment to support unit
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The non-conductive layer acts as a protective intermediary that allows continuous voltage application for efficient image transfer while blocking the harmful effect of electric field attraction on toner particles. The layer isolates the support unit from the electric field, enabling sustained high-speed transfer without particle contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively reduces the likelihood of toner particles being attached to the support unit, minimizing misregistration and ensuring high-quality image transfer by maintaining the support unit non-conductive during the transfer process.

Implementation Method 1

The transfer unit transfers the image formed with particles onto the recording medium by an electric field formed between the transfer unit and the recording medium

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

The use of a jig or support unit that is electrically conductive and connected to ground, combined with a non-conductive layer or controlled voltage application, prevents direct conductivity between the support unit and transfer unit

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4300195B1Image forming apparatus
Publication Date: 2025.02.12 FUJIFILM BUSINESS INNOVATION CORP
  • EP4300195B1 patent drawingFigure 1
  • EP4300195B1 patent drawingFigure 2
  • EP4300195B1 patent drawingFigure 3A~3C

AI summary

An image forming apparatus includes: a transport unit that transports a recording medium; a transfer unit that transfers an image formed with particles onto an image formation surface of the recording medium transported by the transport unit by an electric field formed between the transfer unit and the image formation surface by making contact with the image formation surface; and a support unit that supports the recording medium, is transported to the transfer unit together with the recording medium by the transport unit, and is not directly conductive with the transfer unit.