Luminescent Phosphor Decay Time Authentication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current luminescent phosphor compounds used for authentication can be reverse-engineered, allowing forgeries and counterfeiting, as they rely on spectral signatures that may be determined through spectrometry, making them vulnerable to reproduction and misuse.
Innovation Solution
Incorporating a disturbing ion into the phosphor compound that alters its decay time constant, creating a unique target disturbed decay time constant distinguishable from the undisturbed decay time constant, making it difficult to reverse-engineer without sophisticated equipment and techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spectral signatures are used for authentication, then identification capability is improved, but vulnerability to reverse-engineering increases
Solution Approach 1:
The patent changes the parameter being measured from spectral signature (wavelength-based) to decay time constant (time-based). This parameter transformation makes authentication resistant to reverse-engineering because decay time constants cannot be determined through standard spectrometry, which only measures spectral properties, not temporal decay characteristics.
Solution Approach 2:
The patent transitions from measuring spatial/spectral properties (wavelength domain) to measuring temporal properties (time domain). By measuring the decay time constant in the time dimension rather than the spectral dimension, the system creates an authentication feature that is inaccessible to conventional spectrometric analysis, thereby preventing reverse-engineering while maintaining identification capability.
2Reliability
If disturbing ions are incorporated to alter decay time constant, then security against counterfeiting is improved, but manufacturing complexity increases
Solution Approach 1:
The patent uses parameter changes by selecting specific disturbing ions (such as copper, zinc, or gallium) that systematically alter the decay time constant of the emitting ion. This controlled parameter modification provides a reliable security feature while maintaining relatively simple manufacturing processes, as the ion substitution can be achieved through standard phosphor synthesis methods.
Solution Approach 2:
The patent applies local quality by introducing specific disturbing ions at controlled concentrations (typically 0.01-10 atomic percent) to create a localized effect on the decay time constant. This allows precise control over the authentication parameter without fundamentally changing the overall phosphor structure or requiring complex multi-step manufacturing processes.
3Difficulty of detecting and measuring
If decay time constant is used as authentication parameter, then difficulty of reverse-engineering is increased, but measurement equipment requirements increase
Solution Approach 1:
The patent replaces complex spectrometric measurement systems with simpler time-resolved detection equipment. Instead of using sophisticated spectral analysis to identify phosphor composition, the system uses straightforward temporal measurement of decay characteristics, which can be accomplished with basic photodetectors and timing circuits, thereby reducing equipment complexity while increasing security.
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 altered decay time constant enhances the security of authentication by providing a measurable and difficult-to-reproduce property, increasing the difficulty of counterfeiting and improving the identification of authentic articles.
Implementation Method 1
A luminescent phosphor compound is a compound that is capable of emitting detectable quantities of radiation in the infrared, visible, and/or ultraviolet spectrums upon excitation of the compound by an external energy source
Implementation Method 2
The production of radiation by a phosphor compound is accomplished by absorption of incident radiation by the emitting ion(s) or by either or both the host crystal lattice and the sensitizing ion(s), energy transfer from the host crystal lattice/sensitizing ion(s) to the emitting ion(s), and radiation of the transferred energy by the emitting ion(s)
Implementation Method 3
energy transfer from the host crystal lattice/sensitizing ion(s) to the emitting ion(s)
Data Source
AI summary
Embodiments include luminescent phosphor compounds that include one or more emitting ions and one or more disturbing ions, and methods for their production. An emitting ion in the compound may be characterized by a first decay time constant when the emitting ion is undisturbed. However, a corresponding disturbing ion in the compound, which is different from the emitting ion, causes the emitting ion to have a pre-defined, target disturbed decay time constant that is greater than zero and less than the first decay time constant. An embodiment of an authentication system is configured to measure the decay time constant of a phosphor compound applied to an article, and to determine whether the decay time constant corresponds to a phosphor compound that includes a particular disturbing ion (e.g., in order to determine whether or not the article is authentic).