Telecentric Optical Detector Calibration for Multi-Laser Drift Control

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Solution Overview

Problem

Laser processing systems face challenges in maintaining accuracy due to thermally driven fluctuations, leading to offset and gain drifts, especially when multiple laser devices operate in parallel, requiring frequent recalibration that is often time-consuming and requires human intervention.

Innovation Solution

A laser processing system with a frame structure and optical detector that is movable with limited degrees of freedom, allowing for automated calibration by generating reference marks outside the work field and using a control unit to adjust laser device settings based on precise detection, reducing external intervention and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If traditional calibration methods using marking paper and reference plates are used, then calibration can be performed, but the process is time-consuming and requires human intervention

Engineering Contradiction:
Improveautomation of calibrationVSAvoidcalibration time
Core Design Contradiction:
Extent of automationVSLoss of time

Solution Approach 1:

The system performs self-calibration automatically without human intervention. The control unit controls the laser device to generate reference marks and the optical detector to detect these marks, enabling the system to calibrate itself autonomously during operation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system generates reference marks on the workpiece surface before final processing. These preliminary marks serve as calibration references that the optical detector uses to determine positional accuracy and make necessary adjustments

Inventive Principle:
Principle #10Preliminary action

2Productivity

If multiple laser devices operate in parallel to increase productivity, then output rate improves, but accuracy maintenance becomes more difficult due to thermal fluctuations

Engineering Contradiction:
Improveoutput rateVSAvoidlaser positioning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The optical detector continuously monitors the actual positions of reference marks generated by laser devices. The control unit receives this feedback information and adjusts laser device settings to compensate for thermal drift, maintaining accuracy even during continuous parallel operation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs periodic calibration during operation by generating and detecting reference marks at regular intervals. This periodic self-calibration compensates for thermal fluctuations that occur during continuous parallel laser processing

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If the optical detector has full degrees of freedom for movement, then detection flexibility is improved, but measurement precision decreases due to additional movement variables

Engineering Contradiction:
Improvedetection flexibilityVSAvoidreference mark detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent extracts and eliminates unnecessary degrees of freedom from the optical detector system. By fixing the detector in a telecentric arrangement with limited movement capability, the system removes variables that would otherwise compromise measurement precision while retaining sufficient flexibility for calibration tasks

Inventive Principle:
Principle #2Taking out (Extraction)

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 system achieves improved accuracy and automation in calibration, reducing the need for human intervention and minimizing the impact of thermal fluctuations, enabling more efficient and precise laser processing.

Implementation Method 1

an optical detector (40) for scanning the work field (28) for detecting at least a part of the one or more reference marks (24) generated by each laser device (20)

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3755524B1Automatic calibration of a laser processing system using an integrated telecentric optical detector with limited degrees of freedom
Publication Date: 2022.07.27 RAYLASE GMBH
  • EP3755524B1 patent drawingFigure 1a~1b
  • EP3755524B1 patent drawingFigure 2~3
  • EP3755524B1 patent drawingFigure 4a~4b

AI summary

The present invention relates to a laser processing system (10) comprising a frame structure (12); a work base (14) for supporting a work material (16), wherein the work base (14) defines a work field (28) in a work plane (18); at least one laser device (20) for projecting work light on the work plane (18) and/or on the work material (16), wherein the at least one laser device (20) is attached to the frame structure (12); wherein each laser device (20) is configured for generating one or more reference marks (24) on the work material (16) and/or on the work plane (18) within the corresponding laser field (30), wherein the laser field (30) corresponds to at least a part of the work field (28); an optical detector (40) for scanning the work field (28) for detecting at least a part of the one or more reference marks (24) generated by each laser device (20). wherein the optical detector (40) is movable with respect to the frame structure (12) with not more than two degrees of freedom; and a control unit (50) functionally connected to the optical detector (40) and the at least one laser device (20). wherein the control unit (50) is configured for calibrating the at least one laser device (20) based on the reference marks (24) detected by the optical detector (40). The invention further refers to a related method of calibrating one or more laser devices of a laser processing system.