In-line Decay-Time Scanner for Luminescent Authentication
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Solution Overview
Problem
Existing scanners struggle to accurately determine the decay time characteristics of luminescent materials, especially when the materials are moving at high speeds or consist of mixtures with varying decay times, leading to difficulties in authenticating items marked with luminescent materials in-line on production/distribution lines.
Innovation Solution
A scanner with a dedicated illumination area and detection zone, equipped with a light source and a light sensor with uniform responsivity, allows for the measurement of luminescence intensity profiles over an extended period as the material moves, enabling the determination of decay times and concentrations of different luminescent particles, even at high speeds. The scanner adjusts excitation light intensity and time to ensure reliable signal acquisition and discrimination between mixtures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the scanner uses a conventional light sensor with non-uniform responsivity to detect luminescence light from moving materials, then the device complexity is reduced, but the measurement precision of decay time characteristics deteriorates
Solution Approach 1:
The patent applies local quality by ensuring the light sensor has uniform responsivity specifically in the detection zone where luminescence light is collected. This localized uniformity property allows accurate measurement of decay time characteristics without requiring complex calibration systems elsewhere in the device, thus improving measurement precision while maintaining reasonable device complexity
Solution Approach 2:
The patent changes the responsivity parameter of the light sensor to be uniform across the detection zone. This parameter change enables the sensor to accurately capture luminescence intensity variations over time from moving materials, directly improving decay time measurement precision without requiring complex compensation algorithms
2Measurement precision
If the scanner measures luminescence light over a short time interval, then the productivity increases by enabling faster scanning, but the measurement precision of decay time characteristics deteriorates
Solution Approach 1:
The patent extends the detection zone along the direction of material motion, adding a spatial dimension to the measurement. This allows the scanner to collect luminescence light over an extended effective time interval as material passes through the detection zone, improving decay time measurement precision while maintaining high scanning speed through the conveyor belt system
Solution Approach 2:
The scanner continuously monitors luminescence light before and during the excitation period, preparing intensity data in advance. This preliminary action enables accurate decay time calculation even with short measurement intervals, as the system already has baseline intensity information ready when the measurement window opens
3Reliability
If the scanner uses a single light sensor to detect luminescence light, then the device complexity is minimized, but the reliability of authentication deteriorates when materials move at high speeds
Solution Approach 1:
The patent segments the detection function by using multiple light sensors positioned at different locations within the detection zone. Each sensor captures luminescence light from different portions of the moving material, providing redundant and complementary data that improves authentication reliability at high speeds while keeping each individual sensor simple
4Measurement precision
If the scanner illuminates the luminescent material for a short excitation time, then the productivity increases by enabling faster processing, but the measurement precision of luminescence intensity deteriorates
Solution Approach 1:
The patent uses periodic excitation of the luminescent material with controlled duty cycles. By repeatedly exciting the material and accumulating intensity measurements over multiple periods, the system achieves high precision luminescence intensity measurement even with short individual excitation pulses, maintaining both measurement precision and processing speed
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 solution allows for reliable in-line authentication of luminescent materials by accurately determining decay times and concentrations, even for materials moving quickly, and effectively differentiates between mixtures based on their decay characteristics, enhancing the accuracy and reliability of luminescence-based authentication processes.
Implementation Method 1
A luminescent material typically converts energy of an exciting radiation of a given wavelength into emitted light having another wavelength
Implementation Method 2
Luminescence may be divided in: (i) phosphorescence, which relates to time-delayed radiation emission observable after the excitation radiation is removed
Implementation Method 3
a light sensor for measuring an intensity of the luminescence light emitted by the luminescent material
Data Source
AI summary
Scanner, method of scanning and system for scanning that allows detecting decay time characteristics of light emitted by a luminescent marking on an item which is transported, even at high speed, on a distribution/production line. The detection zone of the scanner's light sensor has a shape elongated along a path of the moving item, and the responsivity of the light sensor, within the wavelength range of the emitted luminescence light, is uniform over the detection zone. The drive current, or drive voltage, powering the excitation light source is adapted to deliver the intensity of the excitation light to the marking so that its light sensor can reliably measure the corresponding luminescence light response, and thus accurately determine a corresponding decay time value.