Mobile Terminal Phosphor Security Verification Ambient Light Adaptation

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Solution Overview

Problem

Existing methods for verifying phosphor-based security features using mobile terminals are unreliable under varying ambient lighting conditions, making it difficult to detect fluorescent-based security features accurately.

Innovation Solution

A method that adjusts parameters such as excitation distance, luminosity, and exposure time based on ambient light intensity, using a smartphone's camera and lighting unit to stimulate and detect the phosphor-based security feature, while accounting for environmental conditions, and evaluates authenticity through image processing and reference data comparison.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a mobile device is used to verify phosphor-based security features, then the verification process becomes portable and accessible, but the detection reliability deteriorates under varying ambient lighting conditions

Engineering Contradiction:
Improveportability of verification deviceVSAvoiddetection reliability of phosphor-based security features
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent dynamically adjusts excitation parameters (illumination intensity, exposure time, distance) based on detected ambient light conditions to maintain reliable phosphor detection across varying lighting environments. The system measures ambient light and modifies excitation parameters accordingly, transforming a static verification process into an adaptive one that compensates for environmental variations.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the excitation distance is reduced to improve detection sensitivity, then the detection precision improves, but the device complexity increases due to need for precise distance control

Engineering Contradiction:
Improvedetection precision of phosphor emissionVSAvoiddistance control mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The mobile device uses its own display screen as both the illumination source and the reference for distance measurement. By displaying a pattern and analyzing its appearance in the camera view, the system automatically determines the optimal excitation distance without requiring external distance measurement devices or complex control mechanisms.

Inventive Principle:
Principle #25Self-service

3Illumination intensity

If the illumination intensity is increased to stimulate phosphor emission, then the emission intensity improves, but the risk of shadowing and overexposure increases

Engineering Contradiction:
Improvephosphor emission intensityVSAvoidshadowing and overexposure
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts illumination intensity based on real-time feedback from the camera and ambient light conditions. Rather than using fixed high intensity, the illumination is adapted during the verification process to achieve sufficient phosphor stimulation while avoiding harmful effects like shadowing and overexposure.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If multiple parameters are adjusted to optimize verification under different lighting conditions, then the adaptability improves, but the control complexity increases

Engineering Contradiction:
Improveverification performance under varying lighting conditionsVSAvoidparameter control system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the mobile device's existing components: the display serves as both screen and illumination source, the camera serves as both regular imaging and phosphor detection, and the processor handles both user interface control and scientific analysis. This integration avoids adding separate dedicated components for each function, managing complexity while achieving adaptability.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables reliable authenticity verification of phosphor-based security features even under different lighting conditions, using a commercially available smartphone, by optimizing excitation and detection parameters, and incorporating real-time adjustments for improved accuracy and user-friendliness.

Implementation Method 1

exciting the phosphor of the phosphor-based security feature for emission by means of the illumination device

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

detecting the emission of the light emitted by the phosphor-based security feature by means of the camera

Methodology Applied
Scientific EffectPhotodetection: Photoelectric Effect

Data Source

PatentEP3955222B1Mobile terminal and method for authenticating an illuminant-based security feature using a mobile terminal
Publication Date: 2025.01.15 BUNDESDRUCKEREI GMBH
  • EP3955222B1 patent drawingFigure 1
  • EP3955222B1 patent drawingFigure 2
  • EP3955222B1 patent drawingFigure 3

AI summary

The invention relates to a method for verifying the authenticity of a phosphor-based security feature (102) using a mobile device (200), comprising the steps of: - detecting the radiance (I0) of the ambient light, - specifying at least one parameter for excitation of the phosphor-based security feature (102) depending on the detected radiance (I0) of the ambient light, - positioning the security feature (102) relative to the image acquisition device (202) by setting or maintaining the at least one parameter for excitation, - exciting the phosphor of the phosphor-based security feature (102) to emission by means of the illumination unit (204), - detecting the emission of the light emitted by the phosphor-based security feature (102) by means of the camera (206).- Evaluation of a series of images (304) or video recording captured by the camera (206) using the evaluation device (208) and assessment of the authenticity of the fluorescent security feature (102) based on reference data (306, 308). The invention also relates to a mobile terminal (200) for carrying out the method.