Laser Optical Alignment Using Wavelength Compensation for Spot Positioning
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Solution Overview
Problem
Existing laser light positioning techniques face challenges in achieving high accuracy and speed in positioning laser spots with small diameters, particularly due to the need for narrow slit widths, which complicates initial adjustment and reduces positioning precision.
Innovation Solution
A laser processing apparatus and optical adjustment method that utilize processing guide light and measurement guide light with specific wavelengths to adjust for chromatic aberration, allowing for precise alignment of processing and measurement light irradiation positions, thereby overcoming the limitations of traditional methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a narrow slit width is used to match the small spot diameter at the focal position, then measurement precision is improved, but the ease of operation deteriorates due to difficulty in quickly capturing the spot position during initial adjustment
Solution Approach 1:
The patent divides the optical path into two separate channels: a measurement optical path using a narrow slit for precise spot position detection, and an adjustment optical path using a broad slit for easy initial positioning. This segmentation allows each channel to be optimized for its specific function without compromise
Solution Approach 2:
The patent introduces a broadband light source as an intermediary tool during initial adjustment. This light source emits light that passes through the broad slit to illuminate the spot position, making it easily visible and captureable without requiring the narrow slit configuration
2Measurement precision
If the slit width is narrowed to match the small spot diameter, then measurement precision is improved, but the speed of capturing spot position deteriorates
Solution Approach 1:
The patent segments the positioning process into two phases: initial positioning using a broad slit for high speed, and final measurement using a narrow slit for high precision. This eliminates the need to compromise between speed and precision in a single configuration
Solution Approach 2:
The patent performs preliminary positioning actions using the broad slit configuration before switching to the narrow slit for measurement. This preliminary action allows the system to quickly establish approximate spot position without the constraints of narrow slit visibility
3Adaptability or versatility
If different wavelengths are used for processing light and measurement light, then functional requirements are satisfied, but chromatic aberration causes deviation between irradiation positions
Solution Approach 1:
The patent introduces a compensating optical element as an intermediary component that counteracts the chromatic aberration effects. This element mediates between the different wavelength requirements and the position alignment requirement by introducing opposite aberration to cancel the original chromatic aberration
Solution Approach 2:
The patent changes the optical parameters (focal length, refractive index) of optical elements based on the specific wavelengths used for processing and measurement. By adjusting these parameters, the system compensates for chromatic aberration and maintains position alignment despite wavelength differences
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 high-accuracy and high-speed positioning of laser spots with different output differences, reducing the impact of chromatic aberration and improving measurement accuracy in laser processing applications.
Implementation Method 1
a laser oscillator that emits processing light with which a processing point of a surface of a workpiece is irradiated
Implementation Method 2
a measurement unit that emits measurement light with which the processing point is irradiated, and detects the measurement light reflected at the processing point
Implementation Method 3
a mirror that combines the processing light and the measurement light
Implementation Method 4
a lens that condenses the processing light and the measurement light on the processing point
Implementation Method 5
Respective wavelengths of the processing guide light and the measurement guide light are set to wavelengths at which a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light due to a chromatic aberration of magnification of the lens
Data Source
AI summary
A laser processing apparatus emits processing light, measurement light, processing guide light, and measurement guide light with which a surface of a workpiece is irradiated. Respective wavelengths of the processing guide light and the measurement guide light are set to wavelengths at which a deviation amount between an irradiation position of the processing guide light and an irradiation position of the measurement guide light due to a chromatic aberration of magnification of a lens, and a deviation amount between an irradiation position of the processing light and an irradiation position of the measurement light due to the chromatic aberration of magnification of the lens are equal to each other. Therefore, positioning of spot positions of a plurality of laser lights having different output differences can be realized with high accuracy and high speed.