Image Forming Control With Toner Density Switching for Transfer Paper

Solution Overview

Problem

Existing image forming technologies face challenges in achieving high-quality transfer printing on fabrics, particularly with iron-on transfer printing, where white-dot defects often occur due to excessive bonding strength between the toner image and the release layer during the primary transfer process.

Innovation Solution

An image forming apparatus and method that selectively form toner images with different area densities for transfer paper and plain paper, using a controller to adjust the toner area density based on the material of the print medium, ensuring a lower area density on transfer paper to facilitate stable primary and secondary transfers and reduce white-dot defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the toner area density is increased to improve image quality, then the image clarity is improved, but white-dot defects occur due to excessive bonding strength between toner and release layer

Engineering Contradiction:

Improveimage qualityVSAvoidwhite-dot defects

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies different toner area densities for different print medium types. Specifically, transfer paper uses a lower toner area density (0.20-0.40) compared to plain paper (0.35-0.55), optimizing the bonding strength locally for each medium type to prevent white-dot defects while maintaining image quality

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the toner area density parameter based on the print medium type. By adjusting this physical parameter, the bonding strength between toner and release layer is optimized for transfer paper to prevent excessive bonding that causes white-dot defects, while maintaining sufficient bonding for plain paper

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the toner area density is decreased to reduce white-dot defects, then white-dot defects are reduced, but the image clarity deteriorates

Engineering Contradiction:

Improvewhite-dot defectsVSAvoidimage quality

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies different toner area densities for different print medium types. Transfer paper uses a lower toner area density (0.20-0.40) compared to plain paper (0.35-0.55), optimizing the bonding strength locally for each medium type to prevent white-dot defects while maintaining image quality

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the toner area density parameter based on the print medium type. By adjusting this physical parameter, the bonding strength between toner and release layer is optimized for transfer paper to prevent excessive bonding that causes white-dot defects, while maintaining sufficient bonding for plain paper

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the bonding strength between toner and release layer is increased to improve transfer stability, then transfer stability is improved, but white-dot defects occur due to excessive bonding

Engineering Contradiction:

Improvetransfer stabilityVSAvoidwhite-dot defects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the toner area density parameter based on the print medium type. By adjusting this physical parameter, the bonding strength between toner and release layer is optimized for transfer paper to prevent excessive bonding that causes white-dot defects, while maintaining sufficient bonding for plain paper

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a lower toner area density for transfer paper (0.20-0.40) compared to plain paper (0.35-0.55), applying just enough bonding strength to achieve stable transfer without excessive bonding that would cause white-dot defects

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS10509339B2Image forming apparatus and image forming method

Publication Date: 2019.12.17 OKI ELECTRIC INDUSTRY CO LTD

AI summary

An image forming apparatus includes an image forming section and a controller. The image forming section selectively forms a first toner image to be printed on transfer paper other than plain paper with use of a toner and forms a second toner image to be printed on the plain paper with use of the toner. The controller controls the image forming section and thereby makes a first area density of the toner in the first toner image and a second area density of the toner in the second toner image differ from each other.