Image Forming Apparatus Using Decolorable and Non-Decolorable Colorants

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Solution Overview

Problem

Conventional image forming methods using decolorable colorants face challenges in maintaining images over time, especially in heated environments, and distinguishing between decolorable and non-decolorable prints, making it difficult to reuse papers with retained information.

Innovation Solution

An image forming apparatus that uses a decolorable colorant for printing and a non-decolorable colorant for identification, storing image data and identification information in a correlated manner, allowing for the reproduction of decolored images by reading identification information and re-forming them using the stored data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a decolorable colorant is used to print images on paper for reuse, then the paper can be reused after decoloring, but the image durability deteriorates and images disappear in heated environments or over time

Engineering Contradiction:

Improvepaper reuse capabilityVSAvoidimage durability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the printing system into two separate colorants: a decolorable colorant for the main image content and a non-decolorable colorant for identification information. This segmentation allows different parts of the printed material to serve different functions - the main image can be decolored for paper reuse while the identification information remains permanent for tracking and verification purposes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the printed output are assigned different colorant properties. The identification information (such as barcodes or text) is printed with a non-decolorable colorant that maintains its visibility and durability, while the main image content is printed with a decolorable colorant that can be erased when heat is applied. This local differentiation of material properties resolves the contradiction between image durability and paper reuse capability.

Inventive Principle:

Principle #3Local quality

2Productivity

If a decolorable colorant is used to enable paper reuse, then sheets can be recycled, but the ability to maintain information over time deteriorates

Engineering Contradiction:

Improvesheet recycling efficiencyVSAvoidinformation retention

Core Design Contradiction:

ProductivityVSLoss of information

Solution Approach 1:

The system creates a permanent copy of the identification information using a non-decolorable colorant that survives the decoloring process. This identification copy serves as a permanent record that can be used to track and retrieve information even after the main image content has been decolored and the paper reused, thus preventing information loss while enabling sheet recycling.

Inventive Principle:

Principle #26Copying

3Adaptability or versatility

If only decolorable colorant is used for printing, then paper reuse is enabled, but the ability to distinguish between decolorable and non-decolorable prints deteriorates

Engineering Contradiction:

Improveprint type discriminationVSAvoidvisual identification ease

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent employs colorant formulations that exhibit different color characteristics or visual properties. The non-decolorable colorant may have a distinct color, fluorescence, or other visual feature that differentiates it from the decolorable colorant. This allows users to visually distinguish between prints that contain permanent identification information and those that are intended for decoloring and reuse, improving ease of operation without compromising adaptability.

Inventive Principle:

Principle #32Color 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

Ensures the longevity of printed information by enabling the reproduction of decolored images, facilitating the reuse of sheets while maintaining data integrity and distinguishing between different types of prints.

Implementation Method 1

a decolorable colorant which becomes colorless by a predetermined chemical reaction

Methodology Applied

Scientific EffectThermal decoloration: Thermochromism

Implementation Method 2

an image forming unit that forms an image based on the image data acquired by the image data acquiring unit on the sheet

Methodology Applied

Scientific EffectElectrophotography:

Data Source

PatentEP2247091B1Image forming apparatus, image forming method, and computer-readable recording medium having image forming program recorded therein

Publication Date: 2019.04.17 TOSHIBA TEC KK

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AI summary

There is provided an image forming apparatus including: an image data acquiring unit that acquires image data of an image formed on a sheet; an identification information acquiring unit that acquires identification information that identifies the sheet on which the image is formed; an image forming unit that forms an image based on the image data acquired by the image data acquiring unit on the sheet with a decolorable colorant which becomes colorless by a predetermined chemical reaction and that forms an identification information image based on the identification information on the sheet with a non-decolorable colorant which does not become colorless by the chemical reaction by which the decolorable colorant becomes colorless; and a storage control unit that stores the identification information and the image data of the image to be formed on the sheet, on which the identification information image corresponding to the identification information is formed, in a predetermined storage region in a correlated manner.