Liquid Developer Carrier Liquid Adjustment for Image Transfer

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Solution Overview

Problem

Existing image forming apparatuses using liquid developers face challenges in controlling carrier liquid shortages, leading to issues such as transfer voids and toner flow defects due to varying carrier liquid penetration speeds in different recording materials.

Innovation Solution

An image forming apparatus with an adjusting device that controls the liquid amount of the carrier liquid based on the type of recording material, using a combination of rollers and blades to regulate the carrier liquid layer thickness and adjust the toner-to-carrier liquid ratio, ensuring optimal transfer efficiency and preventing defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the toner proportion (T/D) in the liquid developer is increased, then the image density is improved, but the viscosity increases causing slower toner migration speed and potential transfer voids

Engineering Contradiction:
Improveimage densityVSAvoidtransfer void
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention dynamically adjusts the T/D ratio parameter of the liquid developer based on the penetration speed characteristics of different recording materials. By changing this physical parameter, the system optimizes the balance between image density and transfer completeness, preventing transfer voids while maintaining high image quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system transitions from using a fixed T/D ratio to a dynamic adjustment mechanism that adapts the liquid developer composition in real-time based on recording material properties. This dynamic approach allows the system to respond to varying penetration speeds and prevent transfer voids across different material types.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the toner proportion (T/D) in the liquid developer is decreased, then the viscosity decreases improving toner migration speed, but excessive carrier liquid remains on the recording material causing image defects

Engineering Contradiction:
Improvetoner migration speedVSAvoidimage defect
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system adjusts the T/D ratio parameter downward for recording materials with slow carrier liquid penetration speed. This parameter change reduces viscosity, enhances toner migration speed, and prevents excessive carrier liquid from causing image defects such as flow, blur, or spreading.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention implements dynamic control of the liquid developer composition based on real-time detection of recording material properties. This allows the system to optimize toner migration speed while preventing image defects by adapting the T/D ratio to match the specific penetration characteristics of each recording material.

Inventive Principle:
Principle #15Dynamics

3Speed

If the carrier liquid penetration speed is high, then the transfer process is efficient, but carrier liquid shortage occurs causing transfer voids

Engineering Contradiction:
Improvecarrier liquid penetration speedVSAvoidcarrier liquid amount
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The system performs preliminary detection of recording material properties and pre-adjusts the carrier liquid amount or T/D ratio before the transfer process begins. This preliminary action ensures that sufficient carrier liquid is available for high-penetration materials, preventing transfer voids while maintaining efficient transfer speed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention incorporates a feedback mechanism that detects the penetration speed characteristics of recording materials and uses this information to adjust the carrier liquid amount or T/D ratio. This closed-loop control ensures that the carrier liquid quantity is optimized for each specific material, preventing both shortage and excess conditions.

Inventive Principle:
Principle #23Feedback

4Quantity of substance

If the carrier liquid penetration speed is low, then the carrier liquid remains on the recording material, but excessive liquid causes image defects

Engineering Contradiction:
Improvecarrier liquid amountVSAvoidimage defect
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The system adjusts the T/D ratio parameter downward for recording materials with low carrier liquid penetration speed. This parameter change reduces the overall liquid content in the liquid developer, preventing excessive carrier liquid from remaining on the recording material and causing image defects.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention dynamically adapts the liquid developer composition based on the detected penetration speed of the recording material. For low-penetration materials, the system reduces the carrier liquid amount or T/D ratio, ensuring optimal liquid quantity that prevents image defects while maintaining sufficient moisture for transfer.

Inventive Principle:
Principle #15Dynamics

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 apparatus effectively manages carrier liquid levels, enhancing transfer efficiency and preventing defects like transfer voids and toner flow, achieving high second transfer efficiency across various paper types.

Implementation Method 1

a toner image is formed on an image bearing member with the liquid developer containing the toner particles and the carrier liquid

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

a value of a penetration speed of the carrier liquid into the recording material

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3264192B1Image forming apparatus
Publication Date: 2020.01.29 CANON KK
  • EP3264192B1 patent drawingFigure 1
  • EP3264192B1 patent drawingFigure 2~3
  • EP3264192B1 patent drawingFigure 4(a)~4(c)

AI summary

An image forming apparatus includes an image bearing member configured to bear a toner image formed using a liquid developer containing toner particles and a carrier liquid, a transfer member, an input portion into which information on a kind of a recording material is inputted, an adjusting device configured to adjust an amount of the carrier liquid of the toner image, and an executing portion configured to execute an operation of the adjusting device depending on the information when the toner image is in the adjusting position. The executing position executes either of a plurality of operations including a first operation in which the amount of the carrier liquid of the toner image is increased, a second operation in which the amount of the carrier liquid is decreased, and a third operation in which the amount of the carrier liquid is not adjusted.