Optical Sensor QC for Value Documents With Two-Stage Screening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing securities lack efficient and reliable quality control, leading to material waste and potential exposure of security features to broad audiences, compromising counterfeiting protection.
Innovation Solution
A method involving two-stage optical radiation testing with varying sensitivities and resolutions is employed, where the first stage detects impurities with high sensitivity and low resolution, and the second stage verifies the presence and quantity of security features with higher resolution and lower sensitivity, using a single sensor system for both stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If comprehensive quality control testing is performed on all semi-finished products with high sensitivity and high resolution, then manufacturing precision and reliability are improved, but loss of substance increases due to rejection of semi-finished products containing impurities that would not interfere with final security features
Solution Approach 1:
The quality control process is segmented into two distinct stages: a first testing stage with high sensitivity and low resolution to detect impurities before feature material application, and a second testing stage with lower sensitivity and high resolution to verify security features. This segmentation allows each stage to be optimized for its specific purpose, preventing premature rejection of semi-finished products while ensuring final quality.
Solution Approach 2:
The first quality control test is performed as a preliminary action before applying feature materials to the semi-finished product. This preliminary testing identifies and eliminates only those products with impurities that would genuinely interfere with subsequent feature application, while preserving products that would have been incorrectly rejected by a single comprehensive test.
2Device complexity
If a single sensor system is used for both testing stages, then device complexity is reduced, but measurement precision may be compromised due to the need to switch between different sensitivity and resolution settings
Solution Approach 1:
The sensor system is designed with dynamic capabilities to switch between different operating modes: a first mode with high sensitivity and low resolution for impurity detection, and a second mode with lower sensitivity and high resolution for security feature verification. This dynamic adaptability allows a single sensor system to achieve the precision requirements of both testing stages without requiring multiple dedicated sensors.
Solution Approach 2:
The sensor system is designed as a universal device that can perform both the first quality control test (high sensitivity, low resolution) and the second quality control test (lower sensitivity, high resolution). This multi-functionality reduces device complexity by eliminating the need for separate sensor systems while maintaining the measurement precision required for both testing purposes through configurable operating modes.
3Loss of substance
If high sensitivity testing is performed early in production, then loss of substance is reduced by avoiding waste of feature materials on impure semi-finished products, but productivity decreases due to the need for multiple testing stages
Solution Approach 1:
The first quality control test with high sensitivity is performed as a preliminary action before applying feature materials to identify and eliminate semi-finished products with impurities. This prevents waste of feature materials on defective products while using a low-resolution test that can be performed quickly, minimizing the impact on production throughput.
Solution Approach 2:
The quality control process is segmented into two efficient stages: a fast, high-sensitivity screening test that prevents feature material waste, followed by a high-resolution verification test. This segmentation optimizes both material efficiency and production speed by matching test characteristics to their specific purposes in the production workflow.
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 reduces material waste and ensures efficient production while maintaining high counterfeit protection by early detection of impurities and precise verification of security features, using a single sensor for both stages.
Implementation Method 1
capturing a first optical radiation emanating from the first semi-finished product with at least one first sensitivity and at least one first resolution of temporal, spatial and/or spectral properties
Data Source
Figure 1
Figure 2~4
Figure 5
AI summary
The invention relates to a method for producing value documents and to a sensor system for quality control during the production of value documents. A first optical radiation (S1) emitted by a first semi-finished product (1) is detected with a first sensitivity (E1) and a first resolution (A1) and is tested using a first test criterion (K1). If the first test criterion (K1) is met, the following steps are performed: introducing and/or applying at least one feature substance (MS) into or onto the first semi-finished product (1), wherein a value document (4) or a second semi-finished product (2) is obtained; detecting a second optical radiation (S2) emitted by the value document (4) or second semi-finished product (2) with at least a second sensitivity (E2) and at least a second resolution (A2); and testing the second optical radiation (S2) on the basis of at least one second test criterion (K2a, K2b) and, if the at least one second test criterion (K2a, K2b) is met, releasing the value document (4) for circulation or releasing the second semi-finished product (2) for use in the production of a value document (4). The first sensitivity (E1) is greater than the second sensitivity (E2) and/or the first resolution (A1) is less than the second resolution (A2) and/or the testing of the first optical radiation (S1) is less selective than the testing of the second optical radiation (S2).