Laser Head Calibration Assembly for Focus and Beam Position Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current calibration methods for additive manufacturing devices with power radiation sources fail to optimize focusing and positioning corrections, leading to non-linear deformations and suboptimal energy transmission on the powder bed.
Innovation Solution
An automatic calibration method using a calibration plate with reference marks and a firing support, where the radiation source generates a calibration pattern, and optical measuring equipment acquires images to determine corrected commands based on the distribution of impact points, allowing for precise Z calibration and improved X and Y corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a three-axis head system with galvanometers is used to control beam positioning and focusing, then positioning precision and focusing control are improved, but non-linear deformations and geometric shifts occur on the work plane
Solution Approach 1:
The patent implements feedback by using a camera to capture images of reference marks on the calibration plate, measuring actual beam positions and focus points, and automatically calculating correction values that are applied to the control system to compensate for geometric distortions and focusing variations across the work plane
Solution Approach 2:
The patent changes control parameters by determining correction values for X, Y positioning and Z focusing based on measured deviations from ideal positions. These correction parameters are stored and applied to adjust the beam control, transforming the system from having systematic errors to achieving uniform precision across the entire work plane
2Use of energy by moving object
If the laser beam is correctly focused at the powder bed level, then energy transmission to the melting point is improved, but focusing varies according to beam inclination and optical path length
Solution Approach 1:
The patent replaces manual focusing adjustment with an automated optical measurement and calculation system. A camera captures focus point positions, and a computer automatically calculates Z-axis correction values for different beam angles and positions, eliminating the need for manual trial-and-error focusing adjustment and ensuring consistent energy transmission across the work plane
3Measurement precision
If calibration plates with reference marks are used to determine X and Y corrections, then positioning corrections are improved, but Z focusing calibration is not optimized
Solution Approach 1:
The patent makes the calibration plate multi-functional by incorporating both reference marks for X-Y positioning calibration and target zones for Z-focus calibration. The same calibration plate and camera system are used to determine all three correction parameters (X, Y, Z), eliminating the need for separate calibration procedures and ensuring comprehensive calibration of the beam control system
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 method optimizes focusing and positioning corrections, ensuring consistent and precise energy transmission across the powder bed, enhancing the accuracy and quality of additive manufacturing processes.
Implementation Method 1
consolidating selected zones on successive layers of powdered material by a total or partial selective fusion carried out with a focused radiation source
Implementation Method 2
the more the laser beam is correctly focused at the level of the powder bed, the greater and more controlled the energy transmitted to the melting point
Data Source
Figure 1
Figure 2~3
Figure 4a
AI summary
The invention relates to an assembly for calibrating a head system of a power radiation source of an additive manufacturing device, comprising: - a calibration plate that has a plurality of reference markings, and - a firing support made of at least one material that is sensitive to the radiation from the source, said support leaving the reference markings of the calibration plate visible when it is installed thereupon, characterised in that the firing support comprises a plurality of windows which are distributed so as to lie over the different reference markings on the calibration plate and leave them visible when the firing support is installed on the calibration plate. The invention also relates to a method for calibrating such a system.