Retroreflective License Plate with Dielectric Security Structure

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Solution Overview

Problem

Current methods for producing motor vehicle license plates with integrated security features are costly, inflexible, and often require additional complex and costly processes, such as hologram seals, which increase production costs and logistical complexities, and cannot be easily individualized for customer requests.

Innovation Solution

A method and device for producing motor vehicle license plates with an optically perceptible security structure integrated into the front surface of the plate blank, using regular or recessed structures that create optical interference effects, allowing for customer-specific customization and integration with existing production processes without requiring metallic reflective layers, thus avoiding the limitations of prior technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hologram seals are used as security features, then optical security is improved, but production cost and device complexity increase

Engineering Contradiction:
Improvesecurity featureVSAvoidproduction process
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the security feature directly into the retroreflective film material itself, eliminating the need for separate hologram seal components. The security feature is integrated as part of the film structure, removing complex attachment processes and reducing overall device complexity while maintaining security functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent combines the security feature with the retroreflective film into a single integrated component. Instead of using separate hologram seals that require thermal transfer and welding processes, the security feature is merged directly into the film material, simplifying the production process and reducing the number of manufacturing steps.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If hologram seals are used as security features, then optical security is improved, but production cost increases

Engineering Contradiction:
Improvesecurity featureVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent eliminates the polyester carrier and separate hologram seal components, extracting only the essential security functionality and integrating it directly into the retroreflective film. This reduces material costs and eliminates the need for expensive thermal transfer equipment and processes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The retroreflective film serves multiple functions simultaneously: it provides retroreflection, contains the security feature, and eliminates the need for separate carrier materials and attachment processes. This multi-functionality reduces overall production costs by consolidating multiple components and processes into a single product.

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

3Illumination intensity

If metallic reflective layers are used, then retroreflectivity is improved, but flexibility and customization are reduced

Engineering Contradiction:
ImproveretroreflectivityVSAvoidcustomization
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent changes the physical state and properties of the reflective layer from metallic to dielectric materials with controlled refractive indices. This allows for parameter adjustments in thickness and material composition to optimize both retroreflectivity and security feature visibility, enabling customization without sacrificing optical performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite dielectric layer structures with different refractive indices to achieve the desired optical properties. These composite materials provide flexibility in designing custom security features while maintaining retroreflectivity, allowing for individualization and customization that metallic layers cannot provide.

Inventive Principle:
Principle #40Composite materials

4Reliability

If security features are integrated during film production, then security is improved, but adaptability for customer-specific requests is reduced

Engineering Contradiction:
Improvesecurity featureVSAvoidindividualization
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent enables dynamic customization of security features by allowing the retroreflective film to be individually tailored after production. The dielectric layer structure can be modified and customized for specific customer requirements while maintaining the integrated security feature, providing both reliability and adaptability.

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 provides a cost-effective, flexible, and environmentally friendly method for producing license plates with enhanced security features that can be easily integrated into existing production systems, allowing for large-area security structures that are invisible or transparent when viewed perpendicularly, while maintaining retroreflectivity and enabling individualization, thus reducing waste and production costs.

Implementation Method 1

The introduced security structure shows an optical effect, in particular a color effect, based on optical interference

Methodology Applied
Scientific EffectOptical interference: Interference

Implementation Method 2

retroreflective films with embedded microlenses and a metallic reflective layer

Methodology Applied
Scientific EffectRetroreflection: Retroreflector

Data Source

PatentEP3408143B1Method for manufacturing a retro-reflecting vehicle number plate, retro-reflecting vehicle number plate, and device for implementing the method
Publication Date: 2020.04.01 ERICH UTSCH
  • EP3408143B1 patent drawingFigure 1~3
  • EP3408143B1 patent drawingFigure 4~5
  • EP3408143B1 patent drawingFigure 6~7

AI summary

The invention relates to an automobile license plate (1) having a laminar-extended sign blank (10), wherein a visually perceptible, laminar-extended security structure (30) is introduced in the surface of the front side of the sign blank, and wherein the introduced security structure (30) displays a color effect based on optical interference, which is based on laminar-extended, regular, elevated or recessed structures in the surface of the sign blank (10). The invention further relates to a method for producing such an automobile license plate (1), and to a production device (100) suitable for carrying out the method.