Laser Marking via Continuous Deflection Mirror Scanning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for creating microstructuring on security documents are time-consuming and costly due to the 'Jump and Shoot' principle, which requires multiple laser pulses and lengthy processing times, especially for large-scale production of security documents like IDs and banknotes.

Innovation Solution

A continuous movement of deflection mirrors in the laser system reduces inertia forces, allowing for a pulse sequence of two or more laser pulses to mark pixels with ultra-short pulses, significantly reducing processing time and increasing scanning speed, thus enhancing the efficiency of microstructuring and pixel creation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple laser pulses are applied to a single location to create small pixels, then manufacturing precision is improved, but processing time increases significantly

Engineering Contradiction:
Improvepixel sizeVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent implements continuous scanning of the laser beam across the substrate without stopping at each pixel location. The laser beam moves continuously while pulses are applied at different positions along the scan path, eliminating the stop-start nature of conventional methods and maintaining continuous useful action throughout the marking process.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces dynamic motion of the laser beam across the substrate during pulse application. By scanning the laser beam continuously at controlled speeds and applying pulses during motion, the system transforms from a static position-based approach to a dynamic motion-based approach, significantly reducing processing time while maintaining precision.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the laser beam is repositioned to each pixel location using deflection mirrors, then manufacturing precision is improved, but processing time increases due to acceleration and deceleration

Engineering Contradiction:
Improvepixel positioning accuracyVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent eliminates the stop-start repositioning cycle by implementing continuous laser beam scanning. The deflection mirrors continuously steer the laser beam across the substrate without stopping at intermediate positions, maintaining continuous motion and eliminating the time losses associated with acceleration and deceleration at each pixel location.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent pre-plans the entire laser beam scan path to cover all pixel locations in a single continuous motion sequence. By organizing the scanning trajectory in advance and executing it without interruptions, the system eliminates the need for repeated positioning operations, significantly reducing processing time while maintaining precision through controlled continuous motion.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If multiple laser pulses are applied consecutively at each location, then marking quality is improved, but the inertial forces of the deflection device increase processing time

Engineering Contradiction:
Improvemarking qualityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent transforms the static multi-pulse application process into a dynamic single-scan process. By scanning the laser beam continuously and applying pulses during motion, the system eliminates the need for the deflection mirrors to repeatedly accelerate and decelerate at each pixel location, significantly reducing inertial forces and processing time while maintaining marking quality through controlled pulse delivery during scan.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements continuous laser beam scanning with pulse application during motion, eliminating the stop-start nature of conventional multi-pulse methods. The useful action of marking continues uninterrupted throughout the scan, with pulses applied at different positions along the continuous scan path rather than requiring repeated stopping and starting at each location.

Inventive Principle:
Principle #20Continuity of useful action

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 shortens processing times and reduces manufacturing costs by minimizing the need for repeated laser beam movement along pixel tracks, enabling faster and more cost-effective production of secure markings with enhanced security features.

Implementation Method 1

Irradiating the layer with pulse sequences comprising a plurality of laser pulses, wherein a pulse sequence is generated as soon as the laser beam reaches a position on the layer where a pixel is to be generated

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3900944B1Method for marking by means of laser pulses
Publication Date: 2025.01.29 BUNDESDRUCKEREI GMBH
  • EP3900944B1 patent drawingFigure 1
  • EP3900944B1 patent drawingFigure 2a
  • EP3900944B1 patent drawingFigure 2b

AI summary

The invention relates to a method (1) for introducing a marking (3) into a layer by means of a laser beam (11) generated by a laser generator (9), wherein the marking (3) has a plurality of pixels (BP) in at least a first path (29) connecting the pixels (BP), the laser beam (11) is guided along the first path (29) connecting the pixels (BP) on the layer (5) by means of at least one movable deflection mirror (15, 17) of a deflection device (13), a movement of the laser beam (11) through the deflection device (13) is carried out continuously, and to generate one of the pixels (BP) of the marking (3) during the continuous movement through the deflection device (13) a pulse train (33) of two or more successive laser pulses (31) of the laser beam (11) is generated.Furthermore, the invention relates to a marking device (7), a layer (5) with a marking (3), the use of a layer (5) for a security document (65) and a computer program.