Relief Structure Display for Forgery Prevention

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Solution Overview

Problem

Existing forgery prevention techniques, such as relief-type diffraction gratings, have limited effectiveness due to ease of formation and limited variability in display changes with illumination angle, leading to a decreasing forgery prevention effect.

Innovation Solution

A display comprising a light-transmitting substrate with a relief structure-forming layer, a light-reflecting layer, and a printed layer, where the relief-structured region has low reflectivity and diffusibility under normal illumination, but exhibits diffracted light-emitting properties under specific conditions, enhancing forgery prevention by changing appearance with observation angle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a relief-type diffraction grating is used to display an image, then the article becomes difficult to forge, but the display image changes are not rich in variety and the forgery prevention effect decreases

Engineering Contradiction:
Improveforgery prevention effectVSAvoidvariety of display image changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent combines multiple functional layers including a relief structure-forming layer with diffractive properties, a light-reflecting layer, and a printed layer containing optical variable ink. This composite structure creates a display that exhibits both diffracted light emission and color change properties, providing rich variety in display image changes while maintaining high forgery prevention effect. The synergistic combination of these materials allows the display to show different images and color changes under various illumination and observation angles.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent incorporates optical variable ink in the printed layer that changes color based on observation angle and illumination conditions. This color change property is combined with the diffracted light emission from the relief structure-forming layer, creating a display that exhibits diverse visual changes. The color change mechanism adds variety to the display image changes, making the display more difficult to forge while enhancing its adaptability to different viewing conditions.

Inventive Principle:
Principle #32Color changes

2Reliability

If a relief structure-forming layer with diffracted light-emitting property is added, then the display becomes difficult to forge, but the device complexity increases

Engineering Contradiction:
Improveforgery prevention effectVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the relief structure-forming layer with the light-reflecting layer and printed layer into a single integrated display structure. The relief structure-forming layer is positioned between the light source and the printed layer, combining multiple functions (diffraction, reflection, and color change) in a unified structure. This merging approach reduces the overall device complexity compared to using separate independent components, while still achieving high forgery prevention effect through the coordinated interaction of the layers.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The relief structure-forming layer serves multiple functions: it acts as a diffraction grating to emit diffracted light, provides a light-reflecting surface, and works in conjunction with the optical variable ink to create color-changing effects. This multi-functionality reduces the need for separate components, thereby reducing device complexity while maintaining or enhancing the forgery prevention effect through the combined capabilities of the layers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If the relief-structured region has low reflectivity and low diffusibility under normal illumination, then the display appears distinct under normal conditions, but the display requires specific illumination conditions to show diffracted light emission

Engineering Contradiction:
Improvevisual distinction under normal conditionsVSAvoidillumination condition requirements
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The display is designed to dynamically change its appearance based on illumination and observation conditions. Under normal illumination, the relief structure-forming layer appears dark due to low reflectivity and low diffusibility, providing a distinct visual appearance. When illuminated at specific angles, the same structure emits diffracted light, creating a dynamic transformation in appearance. This dynamic behavior is achieved through the angle-dependent optical properties of the relief structure, allowing the display to adapt to different viewing conditions while maintaining ease of manufacture through standard printing and lamination processes.

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 solution achieves a higher forgery prevention effect by providing a visual distinction between genuine and forged articles, as the relief structure-forming layer and printed layer change appearance simultaneously with the observation angle, making it difficult to replicate or imitate the display.

Implementation Method 1

a relief structure-forming layer (2) disposed on one surface of the substrate (5) and including a relief-structured region (6) on a surface thereof opposite to its surface in contact with the substrate (5)... exhibits a diffracted light-emitting property under a specific condition

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

a light-reflecting layer (3) disposed on the surface of the relief structure-forming layer (2) including the relief-structured region (6)

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2157458B2Display and information-printed matter
Publication Date: 2021.05.26 TOPPAN HOLDINGS INC
  • EP2157458B2 patent drawingFigure 1~2
  • EP2157458B2 patent drawingFigure 3~4
  • EP2157458B2 patent drawingFigure 5~6

AI summary

[MEANS FOR SOLVING PROBLEMS] A display according to the present invention is characterized in that it comprises a substrate with a light-transmitting property, a relief structure-forming layer disposed on at least one surface of the substrate and including a relief-structured region on a surface thereof opposite to its surface in contact with the substrate, a light-reflecting layer disposed on the surface of the relief structure-forming layer including the relief-structured region, and a printed layer formed on a surface of the substrate opposite to the surface on which the relief structure-forming layer is disposed, or between the relief structure-forming layer and the light-reflecting layer, or on a side of the light-reflecting layer opposite to its surface in contact with the relief structure-forming layer, and in that the relief-structured region is constituted by recessed or protruding portions arranged two-dimensionally, has low reflectivity and low diffusibility under a normal illumination condition, and exhibits a diffracted light-emitting property under a specific condition.