Laser Marking System Using Spatial Light Modulator for Parallel Beam Generation
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Solution Overview
Problem
Current laser marking systems are inefficient in marking larger areas quickly due to their reliance on single-spot scanning and limited power, resulting in prolonged marking times and reduced throughput.
Innovation Solution
A laser manufacturing system incorporating a spatial light modulator with a multi-pixel, linear array of microelectromechanical systems (MEMS) based diffractors, which projects a demagnified and tightly focused line beam onto the workpiece, enabling faster marking of larger areas with higher power lasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single laser beam is scanned across the surface using galvanometric mirrors to mark one spot at a time, then marking precision is maintained, but marking time increases significantly and throughput decreases
Solution Approach 1:
The patent segments the single laser beam into multiple parallel beams by using a spatial light modulator with a multi-pixel linear array. Each pixel in the array corresponds to a separate beam that can mark a different location simultaneously, transforming a sequential single-spot marking process into a parallel multi-spot process, thereby dramatically increasing throughput while maintaining precision through controlled beam positioning
Solution Approach 2:
The patent merges multiple marking operations into a single pass by combining multiple laser beams into a unified marking system. The spatial light modulator integrates multiple pixel-controlled beams that work together to mark entire lines or areas simultaneously, consolidating what would otherwise require multiple sequential scanning operations into one coordinated action
2Productivity
If higher power lasers are used to mark larger areas, then marking time decreases and throughput increases, but the risk of damaging the substrate increases
Solution Approach 1:
The patent segments the high-power laser energy across multiple pixels in the spatial light modulator array. Instead of concentrating all power into a single spot (which would damage the substrate), the energy is distributed across many parallel beams, each delivering lower power density to its target location. This allows the system to use higher total power for faster marking while keeping individual spot power levels safe for the substrate
Solution Approach 2:
The patent transitions from single-spot marking in one dimension to multi-spot line marking by adding spatial distribution across multiple pixels. The spatial light modulator's linear array of pixels creates a one-dimensional array of simultaneous marking points that can be scanned across the substrate, effectively adding a spatial dimension to the marking process that enables higher throughput without increasing power density at any single location
3Manufacturing precision
If focusing lenses are added or changed to achieve finer resolution, then marking precision improves, but scan rates decrease and throughput is penalized
Solution Approach 1:
The patent segments the resolution achievement process by using a spatial light modulator with precisely positioned pixels instead of relying solely on optical focusing. Each pixel in the array can be independently controlled to define marking locations, allowing fine resolution to be achieved through digital pixel addressing rather than requiring high-precision optical focusing, thereby maintaining faster scan rates
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 solution significantly reduces marking time and increases throughput by allowing the use of higher power lasers to mark larger areas simultaneously, improving the efficiency of the laser marking process.
Implementation Method 1
A laser marking system including a spatial light modulator (SLM) with a rectangular array of electrically actuated two-dimensional (2D) diffractors
Implementation Method 2
projection optics operable to project modulated light from the SLM onto a surface of a workpiece to form an anamorphic reflection or image of the SLM that is demagnified along the long-axis of the SLM and tightly focused along the short-axis to form a condensed line beam
Data Source
AI summary
A laser manufacturing system including a spatial light modulator (SLM) with a rectangular array of electrically actuated two-dimensional (2D) diffractors arranged to form multiple pixels spaced linearly along a long-axis thereof, each pixel including a plurality of 2D diffractors electrically ganged together and arranged along a short-axis perpendicular to the long-axis. The system further includes a laser and optics to illuminate the SLM, and projection optics to project modulated light from the SLM onto a surface of a workpiece to form an anamorphic image of the SLM that is demagnified along the long-axis of the SLM and tightly focused along the short-axis to form a condensed line beam to mark the workpiece. The line beam has a sinc2 profile along the short-axis and a top-hat along the long-axis. Demagnification and the resulting long-axis length at the workpiece is chosen based on the pulse-energy of the laser and targeted peak fluence.