Laser-Etched Security Features With Adaptive Beam Focusing
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Solution Overview
Problem
Existing security documents are vulnerable to forgery due to lack of advanced protection features, making them susceptible to imitation and alteration.
Innovation Solution
A device and method that utilize a lens arrangement with electrically movable lenses and adjustable mirrors to control a laser beam, allowing for variable beam diameter and focal length adjustments based on three-dimensional topography data, incorporating personalized or document-specific information to create secure laser-etched features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional security features are used in identification documents, then the documents can be produced easily and read by visually impaired persons, but the documents remain vulnerable to forgery and imitation
Solution Approach 1:
The patent applies local quality by creating security features with spatially varying beam diameters and focal lengths across different regions of the document. The laser beam parameters are locally adapted to generate complex three-dimensional structures that are difficult to replicate, while maintaining simplicity in other areas of the document.
Solution Approach 2:
The patent implements dynamics by using electrically movable lenses and adjustable mirrors that can dynamically change the laser beam's focal length and diameter during the marking process. This allows the system to create variable complexity security features on demand, adjusting the degree of defocusing and beam expansion based on the specific security requirements of different document regions.
2Reliability
If a laser beam with fixed focal length and diameter is used for marking, then the marking process is simple, but the security features lack complexity and personalization
Solution Approach 1:
The patent implements feedback by using an optical detection device to scan the blank and acquire reference values representing three-dimensional topography data. The control device uses this feedback information to automatically adjust the laser beam's focal length and diameter, enabling precise creation of complex security features without manual intervention.
Solution Approach 2:
The patent replaces manual mechanical adjustment of laser parameters with an automated optical system. Electrically movable lenses and adjustable mirrors controlled by a computer system substitute for manual mechanical focusing and positioning, enabling precise control of beam diameter and focal length through electrical signals rather than mechanical manipulation.
3Manufacturing precision
If the distance between the lens arrangement and the blank surface is adjusted for each point, then the laser beam can be precisely focused, but the processing time increases
Solution Approach 1:
The patent applies dynamics by keeping the physical distance between the lens arrangement and blank surface constant, while dynamically adjusting the optical focal length through electrically movable lenses. This allows the focal point to be precisely positioned at different depths without mechanical movement, maintaining high processing speed while achieving variable focal precision.
Solution Approach 2:
The patent replaces mechanical adjustment of the lens-to-blank distance with optical adjustment of the focal length. The control device varies the focal length of the laser beam optically through electrically movable lenses, substituting mechanical positioning with optical focusing to maintain constant physical distance while achieving variable focal precision.
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
Enhances security features by providing increased protection against counterfeiting through personalized and complex laser-etched markings, ensuring documents are difficult to replicate.
Implementation Method 1
A lens arrangement is provided, comprising at least one electrically movable lens and thus configured to shape the laser beam emitted by the laser source
Implementation Method 2
A mirror arrangement is provided, comprising at least one electrically adjustable mirror and thus configured to deflect the laser beam exiting the lens arrangement
Implementation Method 3
A further lens arrangement is provided, which serves to diffract or focus the laser beam deflected by the adjustable mirror
Implementation Method 4
A further lens arrangement is provided, which serves to diffract or focus the laser beam deflected by the adjustable mirror
Implementation Method 5
a laser source for emitting a laser beam
Data Source
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AI summary
The invention relates to a method and a device (100) for embedding a laser-etched security feature into a blank (200) of an identification, valuables, or security document comprising a flat surface (202). Reference values (122) in the form of three-dimensional topographic data, grayscale values, or a reference image are acquired and/or processed. A mirror arrangement (112) is then used to scan the blank (200) in an area designated for the security feature with the laser beam (104), thereby embedding the security feature by means of the laser beam (104). The focal length or diameter of the laser beam (104) is adjusted based on the reference values, depending on its point of impact on the flat surface (202), while maintaining the distance between the surface (202) of the blank (200) and the further lens arrangement (118).The invention also relates to a security feature and an identification, value or security document with such a feature.