Long Afterglow Luminescent Security Marking Authentication
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Solution Overview
Problem
Existing security markings are prone to counterfeiting due to ease of reproduction, require complex and expensive equipment for authentication, and are limited in distinguishing between different compositions of luminescent materials, making them vulnerable to false negatives and unable to link optical appearance to product-specific properties.
Innovation Solution
A method utilizing long afterglow luminescent materials that can be authenticated using a smartphone without additional equipment, focusing on the relative amounts of these materials to create distinct authentication signatures, allowing for robust and reliable verification even in varying conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional luminescent dyes are used in security markings, then the optical appearance can be easily replicated by counterfeiters, but using more sophisticated luminescent materials with specific decay properties requires complex and expensive authentication equipment
Solution Approach 1:
The patent changes the temporal parameter of luminescence by using materials with long afterglow properties (decaying over seconds to minutes) instead of conventional fast-decaying luminescent dyes. This parameter change allows authentication using simple smartphone cameras that can capture the persistent emission, eliminating the need for complex pulsed excitation equipment while maintaining high authentication reliability through the unique decay characteristics of the afterglow materials
Solution Approach 2:
The patent replaces expensive, sophisticated authentication equipment with inexpensive, widely available smartphone cameras. The long afterglow duration allows the cheap smartphone sensor to capture sufficient signal for reliable authentication without requiring specialized detectors or complex optical systems, making the authentication process accessible and scalable
2Ease of operation
If the optical appearance of luminescent markings is used for authentication, then verification can be performed at the place of control, but counterfeiters can mimic the optical appearance using commercially available luminescent dyes
Solution Approach 1:
The patent shifts from evaluating spatial/optical parameters (color, brightness distribution) that are easy to replicate, to evaluating temporal parameters (afterglow decay characteristics) that are difficult to counterfeit. The long afterglow decay profile over seconds to minutes provides a unique temporal signature that maintains ease of observation while significantly improving authentication security against counterfeiting
Solution Approach 2:
The patent introduces dynamic temporal evaluation by monitoring how the luminescence intensity changes over time during the afterglow phase, rather than relying on static optical appearance. This dynamic approach captures the evolving decay characteristics of the long afterglow materials, providing a time-dependent authentication signature that is difficult to replicate with conventional luminescent dyes
3Reliability
If pulsed excitation is used to measure decay properties of luminescent markings, then authentication reliability improves, but the equipment becomes bulky and not easily available
Solution Approach 1:
The patent replaces bulky pulsed excitation equipment with simple continuous or flash illumination sources that can be integrated into smartphones. The long afterglow duration of the materials allows sufficient signal accumulation during the illumination period and during the subsequent decay observation period, enabling accurate decay measurement with simple, inexpensive lighting components rather than requiring complex pulsed laser systems
Solution Approach 2:
The patent uses extended illumination periods or multiple flash exposures to accumulate sufficient signal for accurate decay measurement, rather than relying on intense short pulses. This partial action approach, combined with the long afterglow duration, provides adequate signal-to-noise ratio for reliable authentication using simple illumination sources, trading illumination duration for intensity requirements
4Productivity
If luminescent materials with short decay times are used, then the authentication process is faster, but sophisticated equipment is required to observe the intensity-versus-time emission function
Solution Approach 1:
The patent changes the timescale parameter of the luminescence decay from milliseconds to seconds or minutes by using long afterglow materials. This parameter change allows standard smartphone cameras with typical frame rates to adequately capture the decay profile without requiring specialized high-speed detectors, thereby maintaining authentication speed while using simple equipment
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
This approach enables robust authentication of security markings using smartphones, reducing the need for complex equipment and enhancing security by creating unique signatures based on the relative amounts of long afterglow compounds, thus improving resistance to counterfeiting and environmental influences.
Implementation Method 1
utilizing long afterglow luminescent materials... emitting in the visible spectrum upon excitation... phosphorescence is the time-delayed emission of radiation, observable after the excitation has been stopped
Data Source
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AI summary
The invention relates to a method for authenticating a security marking including at a long afterglow compound capable of emitting long afterglow luminescence light in a given wavelength region, the method allowing to detect a presence and an amount of said long afterglow compound based on comparison of a measured initial intensity value of a spectral component of the emitted light within said wavelength region and associated afterglow time with corresponding reference values representative of a reference amount value of a genuine long afterglow compound. The invention also relates to a reader and system operable to implement the steps of the method.