Luminescent Security Features Using Phosphor Combinations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current luminescent security features in documents lack advanced anti-counterfeiting measures and fail to provide both visible and machine-readable codes, making them vulnerable to counterfeiting and difficult to verify.
Innovation Solution
A coding system using multiple phosphor combinations that emit in non-visible spectral ranges, producing identical spectral codes but different color impressions under UV or IR excitation, which can be verified using specialized techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If luminescent pigments with large spectral spacings between emission lines are used to ensure reliable recognition, then code recognition reliability is improved, but the amount of encodable information and security level deteriorates
Solution Approach 1:
The patent changes the spectral parameters by using phosphors with small spectral spacings (contrary to prior art requirements of large spacings), enabling higher information density while maintaining recognition reliability through advanced detection methods
Solution Approach 2:
The patent uses composite phosphor systems combining multiple phosphors with overlapping emission spectra, creating a multifaceted luminescence code that provides both high information content and reliable verification through spectral deconvolution techniques
2Ease of operation
If luminescent security features are made visible with simple excitation sources for public verification, then ease of operation is improved, but security against forgery deteriorates
Solution Approach 1:
The patent adds spectral dimensionality by using phosphors with closely spaced emission lines that appear similar to the human eye but are distinctly different in spectral space, allowing public verification while maintaining high security through machine-based spectral analysis
Solution Approach 2:
The patent introduces specialized detection devices as intermediaries that bridge between simple public verification and high-security authentication, enabling both public accessibility and anti-counterfeiting through layered verification levels
3Productivity
If phosphors with small spectral spacings are used to increase information content, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
The patent replaces traditional visual/spectrophotometric measurement methods with advanced detection technologies such as spectrofluorometry and spectral deconvolution algorithms, enabling precise measurement of closely spaced emission lines that would be indistinguishable with conventional methods
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
Enhances security by creating luminescent security features that are distinguishable by human eye and machine-readable, providing high-level protection against counterfeiting while maintaining identical spectral codes.
Implementation Method 1
at least three phosphor combinations which are each excitable in the non-visible spectral range, in particular in the ultraviolet or infrared spectral range, and emit after excitation in the visible spectral range
Implementation Method 2
the at least three phosphor combinations are each excitable in the non-visible spectral range, in particular in the ultraviolet or infrared spectral range, and emit after excitation in the visible spectral range
Data Source
Figure 1
Figure 2a~2c
Figure 3a~3e
AI summary
The invention relates to a coding system for forming a security feature in or on one or a plurality of security or valuable documents, comprising at least two individual phosphors, and at least three phosphor combinations formed with the at least two individual phosphors, wherein the at least three phosphor combinations are applied or attached in the form of at least three luminescent security elements for the security feature in or on said one or said plurality of security or valuable documents, wherein each of the at least three phosphor combinations has an identical spectral sequence of the emission lines and/or emission bands to which a code is assigned, and the at least three luminescent security elements of the security feature have different color coordinates in a CIE standard colorimetric system under predefined excitation conditions, with the result that they bring about different color impressions for an observer.