Laser Focus Diameter Control for Corners and Small Contours

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current laser cutting systems cannot dynamically adjust the focus diameter of the laser beam, leading to compromised cutting quality and productivity due to fixed process parameters, particularly in corners and small contours, where laser power and feed rate adjustments are insufficient.

Innovation Solution

A computer-implemented method for dynamically adjusting the focus diameter of a laser beam emitted from a laser processing head, using a configuration module to adjust the focus diameter based on pre-defined trigger events such as changes in cutting gap width, speed, acceleration, and geometry, allowing for speed-dependent, acceleration-dependent, and geometry-based adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fixed process parameters are used in laser cutting, then the device complexity is reduced, but the cutting quality deteriorates in corners and small contours

Engineering Contradiction:
Improvecutting qualityVSAvoidparameter adjustment system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic adjustment of the focus diameter during the cutting process based on real-time detection of geometric features. The focus diameter is varied according to the curvature radius of the contour being cut, allowing optimal energy concentration for both straight sections and corners. This dynamic adaptation resolves the contradiction by enabling high cutting quality across all contour types without requiring multiple fixed parameter sets or complex manual adjustments.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the focus diameter parameter dynamically during processing based on the detected contour geometry. By adjusting the focus diameter according to the curvature radius (smaller diameter for sharp corners, larger for straight sections), the system optimizes laser energy distribution for different geometric features. This parameter adaptation enables consistent high cutting quality without increasing device complexity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If laser power and feed rate are adjusted dynamically, then productivity is improved, but cutting quality deteriorates due to insufficient adaptation to local geometry

Engineering Contradiction:
Improvecutting speedVSAvoidcutting quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent adds focus diameter as a dynamically adjustable parameter alongside laser power and feed rate. The focus diameter is specifically adapted to the local geometry (curvature radius) of the contour being cut. This additional parameter control enables the system to maintain high cutting quality in corners and small contours while preserving high productivity in straight sections, resolving the insufficiency of power and feed rate adjustments alone.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different focus diameters to different local regions of the workpiece based on their geometric characteristics. Sharp corners and small contours receive smaller focus diameters for concentrated energy, while straight sections receive larger focus diameters for faster processing. This local adaptation of the focus diameter complements the global adjustments of power and feed rate, achieving both high productivity and consistent quality.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If focus diameter is kept constant, then the device complexity is reduced, but the cutting quality deteriorates in corners and small contours

Engineering Contradiction:
Improvecutting qualityVSAvoidfocus diameter adjustment system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical adjustment systems with a computational approach. The focus diameter is determined through calculations based on detected contour geometry and stored adjustment functions, rather than through mechanical linkages or manual intervention. This substitution of calculation and control software for mechanical complexity achieves high cutting quality while keeping the physical device relatively simple.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent dynamically changes the focus diameter parameter based on the detected curvature radius of the contour. By storing adjustment functions that map curvature radius to optimal focus diameter, the system automatically selects appropriate parameters without complex mechanical systems. This computational parameter adaptation resolves the contradiction between device simplicity and cutting quality.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4144474B1Method, apparatus and system for dynamically adjusting focus diameter of a laser cutting apparatus
Publication Date: 2024.08.28 BYSTRONIC LASER AG
  • EP4144474B1 patent drawingFigure 1
  • EP4144474B1 patent drawingFigure 2
  • EP4144474B1 patent drawingFigure 3

AI summary

The present invention relates to an adaptation module (AM) for dynamically adjusting the focus diameter of a laser beam of a laser processing head of a laser cutting machine for processing, in particular planar, profiled or tubular, workpieces, which is configured to carry out the method according to one of the preceding claims, with a test block (AM1) configured to check whether a preconfigurable trigger event is present, and with a processor (AM2) which - if the test block has detected a preconfigurable trigger event - is intended to execute an adaptation function to adjust the focus diameter during a processing operation along a path traversed by the laser processing head.