Intermediate Transfer Belt Ionic Electronic Conductivity

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Solution Overview

Problem

Image forming apparatuses using electrophotography face challenges in securing good primary transferability due to changes in electrical resistance of intermediate transfer belts, particularly in varying environmental conditions, leading to potential image defects.

Innovation Solution

An image forming apparatus with an intermediate transfer belt composed of multiple layers, where the thickest layer has ionic conductivity and a second layer with electronic conductivity and lower electrical resistance, allowing electric current to flow in the circumferential direction to maintain consistent primary transfer voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electric current flows in the circumferential direction of the intermediate transfer belt to perform primary transfer, then primary transfer can be achieved, but the primary transfer voltage drops due to electrical resistance changes in varying environments

Engineering Contradiction:

Improveprimary transferabilityVSAvoidprimary transfer voltage

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The intermediate transfer belt is divided into multiple layers with different electrical conductivity characteristics. The first layer (closest to photosensitive drums) has higher electrical conductivity to minimize voltage drop at the primary transfer interface, while the second layer has lower electrical conductivity to control overall current flow and reduce heating effects. This segmentation allows the belt to simultaneously achieve reliable primary transfer and maintain stable transfer voltage across varying environmental conditions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the intermediate transfer belt are assigned different electrical conductivity properties to optimize local functions. The first layer near the primary transfer portion has higher conductivity to ensure adequate current flow for reliable toner transfer, while the second layer has lower conductivity to limit total current and prevent excessive voltage drop. This local differentiation resolves the contradiction between achieving sufficient transfer current and maintaining voltage stability.

Inventive Principle:

Principle #3Local quality

2Reliability

If the intermediate transfer belt is made with ionic conductivity material to improve transfer properties, then transfer performance is enhanced, but electrical resistance changes significantly with environmental conditions

Engineering Contradiction:

Improvetransfer performanceVSAvoidelectrical resistance

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The intermediate transfer belt uses a composite structure with two layers of different materials having distinct electrical conductivity properties. The first layer employs ionic conductivity material for optimal transfer performance, while the second layer uses material with lower and more environmentally stable conductivity. This composite construction allows the belt to maintain both high transfer performance and electrical resistance stability across varying temperature and humidity conditions.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the electrical conductivity parameter across different layers of the intermediate transfer belt. By creating a gradient where the first layer has higher conductivity and the second layer has lower conductivity, the system optimizes the balance between achieving sufficient current flow for transfer and limiting overall resistance changes due to environmental variations. This parameter differentiation resolves the contradiction between transfer performance and resistance stability.

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 primary transfer voltage across different environments, reducing the occurrence of image defects and improving the reliability of the image forming process.

Implementation Method 1

the thickest layer has ionic conductivity

Methodology Applied

Scientific EffectIonic conductivity: Conduction (electrical)

Implementation Method 2

a second layer with electronic conductivity and lower electrical resistance

Methodology Applied

Scientific EffectElectronic conductivity: Conduction (electrical)

Implementation Method 3

by applying voltage from the power source to the current supply member

Methodology Applied

Scientific EffectElectrical voltage application: Electric Field

Data Source

PatentUS11143987B2Imaging forming apparatus with enhanced primary transferability where primary transfer is performed with electric current flowing in circumferential direction of intermediate transfer belt

Publication Date: 2021.10.12 CANON KK

AI summary

An intermediate transfer belt includes a base layer that has ionic conductivity and is a thickest layer out of multiple layers making up the intermediate transfer belt with respect to the thickness direction of the intermediate transfer belt, and an inner layer having electronic conductivity and a lower electrical resistance than the base layer.