CW Laser Processing with Delay Control for Thermal Lens Suppression
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Solution Overview
Problem
Conventional laser processing apparatuses face challenges in suppressing the thermal lens effect during continuous-wave laser irradiation, which affects processing quality and requires costly and complex setups to correct for non-uniform thermal expansion in condenser lenses.
Innovation Solution
A laser processing apparatus that calculates energy values for each processing step and sets a predetermined delay time between processes when the accumulated energy exceeds a threshold, and optionally rotates the condenser lens to manage thermal lens effects, allowing for stable processing with a single apparatus for both material and surface processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a continuous-wave laser is used for both material processing and surface processing, then equipment costs are reduced, but heat accumulation in the condenser lens causes thermal lens effect and reduces processing quality
Solution Approach 1:
The patent applies periodic action by controlling the laser irradiation in a cyclic manner with multiple irradiation periods and intermediate cooling periods. The control unit irradiates the laser beam multiple times (first through fourth irradiation periods) with intermediate delays (first and second cooling periods) to allow heat dissipation from the condenser lens, preventing thermal lens effect while maintaining processing quality and using a single continuous-wave laser apparatus.
2Manufacturing precision
If multiple laser oscillators are used for different processing types, then processing quality is maintained, but equipment costs increase
Solution Approach 1:
The patent applies universality by designing a single continuous-wave laser apparatus that can perform both material processing (welding) and surface processing (marking) through controlled multi-stage irradiation. The control unit manages different irradiation parameters and timing for different processing objectives, making one apparatus versatile for multiple processing types without requiring separate laser oscillators.
Solution Approach 2:
The patent applies preliminary action by performing preliminary irradiation (first and second irradiation periods) before final processing (third and fourth irradiation periods). The initial irradiation stages prepare the workpiece and allow heat management, while subsequent stages complete the desired processing outcome, enabling both material and surface processing with controlled thermal effects.
3Productivity
If laser irradiation is performed continuously without delay, then productivity is high, but thermal lens effect increases and processing quality deteriorates
Solution Approach 1:
The patent applies periodic action by structuring the laser irradiation as multiple discrete periods (first through fourth irradiation periods) separated by cooling periods. This periodic irradiation pattern maintains productivity through multiple processing passes while allowing thermal management between passes to preserve processing quality.
Solution Approach 2:
The patent applies preliminary action by performing initial irradiation passes (first and second irradiation periods) that prepare the workpiece and establish thermal conditions, followed by subsequent irradiation passes (third and fourth periods) that complete the processing. This staged approach balances productivity with quality control.
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 approach effectively suppresses the thermal lens effect, enabling reliable and efficient performance of both welding and marking with reduced equipment costs and improved traceability, while minimizing repeatability errors and processing time.
Implementation Method 1
a condenser lens for concentrating the continuous-wave laser beam onto a workpiece
Implementation Method 2
the lens itself absorbs a laser beam and has an increased temperature
Implementation Method 3
heat accumulation due to continuous laser beam incidence on a condenser lens can be increased excessively, causing the thermal lens effect
Implementation Method 4
irradiating the workpiece with the continuous-wave laser beam multiple times according to processing data to perform processing multiple times
Data Source
AI summary
A laser processing apparatus 10 includes a continuous-wave laser oscillator 12 for generating a continuous-wave laser beam, a condenser lens 18 for concentrating a continuous-wave laser beam onto a workpiece, and a delay time setting means for calculating an energy value for each processing by a continuous-wave laser beam irradiation on the basis of processing data and accumulating the calculated energy value, and setting a predetermined delay time between the processings when the accumulated energy value exceeds a predetermined threshold.