Laser Processing Focal Position Adjustment via Wavelength Selection
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Solution Overview
Problem
Conventional laser processing apparatuses struggle to accurately correct the focal position of a laser beam in real time, especially when the surface displacement of a workpiece is not constant, leading to reduced processing efficiency due to the large spot diameter of the detecting laser beam and inability to measure surface displacement during processing.
Innovation Solution
A laser processing apparatus equipped with a surface displacement detecting system that uses a detecting light source capable of oscillating light at multiple wavelengths, allowing for real-time adjustment of the focal position by selecting an appropriate wavelength for the detecting light to focus on or near the workpiece surface, regardless of its thickness, enabling accurate measurement and correction of the focal position during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the focal position of the processing laser beam is set inside the workpiece at a deep position, then the processing accuracy is improved, but the spot diameter of the detecting laser beam on the surface becomes large, reducing measurement accuracy
Solution Approach 1:
The patent introduces a detecting laser beam with a wavelength different from the processing laser beam as an intermediary measurement tool. This detecting beam serves as a mediator that can focus on the workpiece surface independently of the processing beam's focal depth, enabling accurate surface displacement measurement even when the processing focal point is deep inside the workpiece.
Solution Approach 2:
The patent changes the wavelength parameter of the detecting laser beam to be different from the processing laser beam. This parameter change allows the detecting beam to have different optical properties, specifically enabling it to focus on the surface while the processing beam focuses inside the workpiece, thus resolving the contradiction between deep processing focus and surface measurement accuracy.
2Productivity
If the focal position of the processing laser beam is set inside the workpiece, then the processing effectiveness is improved, but real-time measurement of surface displacement becomes impossible, reducing processing efficiency
Solution Approach 1:
The patent enables continuous real-time measurement of surface displacement during laser processing by using the detecting laser beam that operates simultaneously with the processing beam. The detecting beam continuously monitors surface displacement throughout the processing operation, providing continuous feedback information without interrupting the processing workflow.
Solution Approach 2:
The patent implements a feedback mechanism where the detecting laser beam measures surface displacement in real time, and this measurement information is fed back to adjust the focal position of the processing laser beam dynamically, enabling adaptive control during processing.
3Adaptability or versatility
If a single wavelength detecting laser beam is used, then the device complexity is reduced, but the ability to focus at different depths is limited, reducing adaptability
Solution Approach 1:
The patent utilizes wavelength as a controllable parameter of the detecting laser beam to achieve different focal positions. By changing the wavelength parameter, the detecting beam can be focused at different depths within the workpiece, providing adaptability without adding complex mechanical adjustment mechanisms.
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
Enables real-time correction of the laser beam's focal position, ensuring accurate processing even with varying surface displacements, thereby improving processing efficiency and accuracy by allowing surface displacement measurement during laser processing.
Implementation Method 1
a detecting light source capable of oscillating light having a plurality of wavelengths different from the wavelength of the laser beam; a wavelength selecting section configured to select one of the plurality of wavelengths as the wavelength of detecting light
Implementation Method 2
a detecting light applying section configured to introduce to the focusing lens the detecting light oscillated from the detecting light source and having the wavelength selected by the wavelength selecting section
Implementation Method 3
a detecting section configured to detect reflected light reflected on the workpiece by the application of the detecting light to the workpiece
Implementation Method 4
focal position adjusting means for adjusting the position of the focusing lens according to the result of detection by the surface displacement detecting means
Data Source
AI summary
A laser processing apparatus including a holding unit for holding a workpiece, a processing unit for applying a laser beam to the workpiece held by the holding unit, a surface displacement detecting unit for detecting a surface displacement of the workpiece, and a focal position adjusting unit for adjusting the position of a focusing lens provided in the processing unit according to the surface displacement detected. The surface displacement detecting unit includes a detecting light source capable of oscillating light having a plurality of wavelengths different from the wavelength of the laser beam and a wavelength selecting section configured to select one of the plurality of wavelengths as the wavelength of detecting light. The detecting light having the selected wavelength is focused by the focusing lens and applied to the workpiece.