Polygon scanners and galvanometer scanners are not competing technologies in every application. In many laser processes, they complement each other: the polygon scanner provides high-speed line deflection, while the galvo adds flexible positioning within the working field.
What a galvo scanner does best
Galvo scanners are a flexible solution for two-dimensional laser processing. They can position the beam freely within the available field and are well suited to contours, variable geometries and applications that require frequent changes in the scan path.
The decisive advantages are flexibility, simple adaptation to different geometries and straightforward integration into many laser systems. For smaller and medium-sized working fields, a galvo solution is often the right starting point.
Where a polygon scanner has its strengths
A polygon scanner deflects the laser beam at very high speed along a scan line. This makes it particularly interesting for large-area processing, continuous material handling and processes in which the available laser power should be used efficiently.
MOEWE polygon scanners are designed for high-speed beam deflection and real-time control. Depending on the configuration and optics, they support applications such as marking, microstructuring, surface cleaning, drilling, cutting and engraving. Bitmap and line-processing modes also make it possible to process digital patterns and parameterised scan jobs.
Why combine a polygon scanner with a galvo?
The combination uses the strengths of both systems. The polygon scanner generates the fast scan lines, while the digitally controlled galvo shifts the position of these lines. This creates a two-dimensional processing field without having to move the complete scanner mechanically for every line.
The result can be a high-throughput process with flexible positioning. Depending on the application, additional axes, rotary units or roll-to-roll transport can be integrated as well. This is especially useful when a moving substrate must be processed continuously or when a large area needs to be covered quickly.
Typical applications
- Large-area laser marking and surface structuring
- Continuous processing of films, foils or other moving substrates
- Laser cleaning, cutting or drilling of thin materials
- Engraving and parameterised 2D or 2.5D processing
- Processes that combine high scan speed with changing geometries
When does the combination make sense?
A polygon scanner and a galvo are worth combining when both speed and flexible positioning are important. Typical indicators are:
- The process must cover a large area within a short cycle time.
- The workpiece or substrate is moving continuously.
- Scan lines, contours or processing windows need to change during the process.
- The system benefits from synchronisation between laser, scanner and external axes.
- The optics, aperture, focal length and laser parameters are compatible with the required process window.
What should be clarified during system design?
The right solution depends on more than the nominal scan speed. Working-field size, focal length, laser wavelength and power, material behaviour, required resolution, duty cycle and the motion of the workpiece all influence the design.
It is also important to define the data path and synchronisation at an early stage. Real-time processing, encoder feedback and the selected interface determine how reliably the scanner, laser and motion system work together.
Conclusion
A galvo scanner is the flexible choice for freely positioning a laser beam. A polygon scanner is the high-speed specialist for line-based processing and large-area throughput. Combining both can therefore be useful wherever a process needs high productivity without giving up flexible positioning.
The best configuration is always application-specific. MOEWE supports the evaluation of scanner concept, optics, control and integration for the intended laser process.