Value Document Sensors Combining Intensity Courses for High-Speed Testing
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Solution Overview
Problem
Existing methods for determining the decay time of luminescent substances on value documents at high transport speeds are imprecise due to spatial structures on the documents, leading to inaccurate luminescence intensity measurements.
Innovation Solution
A method and sensor that detect multiple intensity courses from different locations on a moving value document, combine these into a single intensity course, and determine the time constant of the luminescence using a non-linear least-square fit or decay quotient, allowing precise determination of the luminescent substance's decay time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If value documents are transported at high speeds past stationary sensors, then productivity increases, but measurement precision deteriorates due to spatial structures causing inaccurate luminescence intensity measurements
Solution Approach 1:
The patent divides the value document into multiple measurement segments by detecting luminescence intensity at multiple discrete locations along the transport direction. Each location provides a separate intensity course, and these segmented measurements are later combined to achieve accurate decay time determination despite high transport speeds and spatial structures
Solution Approach 2:
The patent combines multiple intensity courses from different measurement locations into a single composite intensity course. This merging process integrates data from various segments of the value document, allowing accurate decay time determination that is independent of local spatial structures while maintaining high transport speed operation
2Productivity
If decay time measurement is performed at multiple discrete time points during high-speed transport, then productivity is maintained, but measurement precision deteriorates because different points on the value document are measured at different time points
Solution Approach 1:
The patent segments the decay time measurement process by performing measurements at multiple discrete locations along the value document during transport. Each location provides a localized intensity course that captures the decay behavior at that specific point, and these segmented measurements are subsequently combined to reconstruct the overall decay characteristics
Solution Approach 2:
The patent adds the spatial dimension to the time-based decay measurement by measuring at multiple locations along the transport direction. This transforms the measurement from a single temporal decay curve into a spatio-temporal dataset, where the combination of spatial segments compensates for the effects of high-speed transport and spatial structures
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 method provides accurate determination of luminescent decay times, independent of spatial structures on the document, enhancing the reliability of value document authentication and classification.
Implementation Method 1
the value documents have a security feature with a luminescent substance which, in reaction to a correspondingly suitable excitation by an excitation source, preferably by an excitation pulse, emits a luminescence
Implementation Method 2
illuminate them with light pulses, and to detect the luminescence intensity of the value document
Data Source
AI summary
A method for checking value documents, in particular with regard to their authenticity and/or with regard to their value-document type, involves the following steps: detecting a first plurality of intensity courses on a value document, combining the first plurality of intensity courses or a second plurality of intensity courses selected from the first plurality into a combined intensity course, determining a time constant τ of the combined intensity course, checking the value document based on the time constant τ of the combined intensity course. A corresponding sensor is provided for checking value documents, and an apparatus enables value-document processing with the aforementioned sensor.