Laser Beam Width Adjustment for Uniform Circular Irradiation
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Solution Overview
Problem
Laser processing apparatuses face issues with variations in the area of laser beam irradiation due to elliptical cross-sections, leading to potential defects during processing.
Innovation Solution
A laser processing apparatus with a width adjuster comprising first and second width adjusting portions, each with convex and concave surfaces of different curvatures, adjusts the laser beam cross-section to a perfectly circular shape, using a beam expander and F-theta lens to maintain consistent irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a laser beam with an elliptical cross-section is used for processing, then the laser source can output high power, but the area where the laser beam is irradiated varies along the processing path, leading to potential defects
Solution Approach 1:
The patent changes the geometric parameters of the laser beam by introducing optical elements (cylindrical lenses or prism pairs) that modify the beam's cross-sectional shape from elliptical to circular. This parameter transformation ensures uniform irradiation area along the processing path while preserving the high power output, thereby resolving the contradiction between power and processing reliability
Solution Approach 2:
The patent introduces intermediary optical components (width adjusters consisting of cylindrical lenses or prism pairs) between the laser source and the scanner. These intermediaries transform the elliptical beam into a circular beam, acting as mediators that enable both high power transmission and uniform irradiation, thus resolving the reliability issue without sacrificing power
2Productivity
If the cross-section of the laser beam is elliptical, then the laser processing can be performed, but the area where the laser beam is irradiated varies, causing defects in the processed material
Solution Approach 1:
The patent transforms the beam cross-sectional parameter from elliptical to circular using optical elements, ensuring that the irradiation area remains constant along the processing path. This parameter change maintains processing efficiency while eliminating precision defects caused by variable irradiation areas
Solution Approach 2:
The patent performs preliminary beam shaping before the laser beam reaches the scanner and processing area. By pre-adjusting the beam cross-section to be circular using width adjusters, the system ensures uniform irradiation throughout the entire processing path, preventing precision defects before they occur
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
Prevents variations in laser beam irradiation area, ensuring consistent processing and reducing defects by converting elliptical cross-sections to circular, enhancing processing reliability.
Implementation Method 1
Each of the first width adjusting portion and the second width adjusting portion may comprise a convex surface and a concave surface, and the convex surface and the concave surface may have different curvatures
Implementation Method 2
an F-theta lens for condensing the laser beam whose irradiation position has been determined
Data Source
AI summary
A laser processing apparatus includes a laser source; a width adjuster that adjusts a width of a laser beam irradiated from the laser source; and a scanner that adjusts an irradiation direction of the laser beam having passed through the width adjuster, wherein the width adjuster includes a first width adjusting portion and a second width adjusting portion arranged on a traveling direction of the laser beam, a focal length of the first width adjusting portion is equal to or greater that about 20,000 mm and a focal length of the second width adjusting portion is equal to or greater than about 20,000 mm.