Ultrasonic Document Authentication via Window Transmission Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for authenticating documents of value, such as banknotes, struggle to reliably detect the presence and integrity of security features like transparent windows, particularly in the presence of production-related fluctuations and potential damage.
Innovation Solution
The method employs ultrasonic transmission sensors to detect and analyze ultrasonic properties across specific test areas on documents, determining if the measured ultrasonic transmission values exceed predetermined criteria, indicating the presence and authenticity of a window, and checks for damage by comparing values against minimum and maximum thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If optical detection methods are used to detect transparent windows, then the detection can be performed continuously during transport, but the reliability is reduced due to production-related fluctuations and damage
Solution Approach 1:
The patent replaces optical detection methods with ultrasonic detection. Instead of using light to detect the window, ultrasonic waves are transmitted through the document and the acoustic transmission characteristics are analyzed. This substitution of the detection physical principle (from optical to acoustic) enables reliable detection of the window's presence and integrity while maintaining continuous detection capability during transport.
Solution Approach 2:
The patent changes the detection parameter from optical properties to ultrasonic transmission properties. By measuring the transmission of ultrasonic waves through different regions of the document (window area versus non-window area), the system can reliably identify the window's presence and detect damage. The ultrasonic transmission characteristics provide more stable and reliable parameters that are less affected by production variations and damage.
2Reliability
If ultrasonic transmission sensors are used to detect window presence and integrity, then the reliability of authentication is improved, but the device complexity increases
Solution Approach 1:
The patent divides the document surface into multiple test areas (first test area and second test area) with different expected ultrasonic transmission characteristics. By segmenting the detection region and comparing transmission values against region-specific reference values, the system achieves reliable authentication while using a relatively simple sensor arrangement. The segmentation approach allows the use of straightforward threshold comparisons rather than complex analysis algorithms.
3Measurement precision
If multiple test areas with different ultrasonic transmission characteristics are examined, then the accuracy of window detection is improved, but the measurement time increases
Solution Approach 1:
The patent pre-establishes reference values for ultrasonic transmission in different test areas (first reference value for window area, second reference value for non-window area) before the actual authentication process. During detection, the system simply compares measured transmission values against these pre-stored references, eliminating the need for real-time complex analysis. This preliminary preparation of reference data enables fast, accurate comparisons that maintain high detection precision while minimizing measurement time.
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 provides a high degree of certainty in authenticating documents by accurately identifying the presence and condition of security features, reducing the impact of production fluctuations and damage, thereby enhancing the reliability of document authentication.
Implementation Method 1
spatially resolved measured values for an ultrasonic transmission of an ultrasound through the document of value are determined by means of a transmission sensor
Data Source
Figure 1~11
Figure 2~4
Figure 5~9
AI summary
A method is described for checking a document of value of a specified type of document of value having a window that has a film region in which the locally resolved measurements for an ultrasonic transmission of the document of value are determined and in which it can be checked using the measurements whether the ultrasonic transmission according to a specified criterion for a specified number of locations in a specified checking region is greater than the specified minimum ultrasonic transmission that is characteristic for a specified section of value of the specified type of document of value outside the checking region.