The Impact of Precise Mirror Systems on Micro-Character Processing

In this paper, we analyze the performance of the galvanometer scanning system in the processing of micro characters, and discuss the impact of the system on processing accuracy, efficiency and stability.Combining laser marking techniques with a detailed analysis of the system parameters optimization method, the book provides users who need high-precision microfabrication with a practical reference.

Why does the processing of tiny letters require a precise galvanometer?

People who have done laser marking may have a deep understanding of this problem. When attempting to mark characters smaller than 0.5 mm on metals and plastics, a conventional galvanometer system often results in blurry edges and strokes that stick together.The precise scanning mirror system is able to control the positioning accuracy to within ± 2μm by using high dynamic response motors and optimized control algorithms.Our laboratory has made comparative tests with mirrors of different brands, and found that the error in repeated positioning of the high-precision system is 60 % less than that of the ordinary system. This is an important index for users who require long-term stable production.

Three key factors emerged from the tests.

Speed vs. precision

During testing, the scanning speed was gradually increased from 800mm / s to 2000mm / s. The results were very interesting: when the speed exceeded 1500mm / s, the strokes of the characters began to show "tails" with the ordinary mirror, while the precision system only showed slight deformation at 1800mm / s.The faster the speed, the better the efficiency, but it also leads to greater heat dissipation.

Control of the size of the spot of focused light.

Experiments comparing 20-μm and 50-μm spot sizes showed that, although the smaller spot size could produce finer strokes, it required more stable galvanometers.In particular, when processing curved surfaces, the precise system's dynamic focusing module can automatically compensate for changes in focal length. This is especially useful in the case of engraving QR codes on the Home button of mobile phones.

Environmental vibrations.

Many users tend to overlook the influence of the workshop environment.We tested the two systems, one on a vibration isolation table and the other on a standard workbench, for 48 hours of continuous processing, and the results showed that the standard galvanometer system's character drift increased over time, while the precision system, which has its own vibration compensation algorithm, maintained stability, with a 40 % increase in overall stability.

Suggestions for practical applications.

The parameters need to be set according to the local situation.

We found that the speed of the scanning beam needed to be between 10 % and 15 % lower for stainless steel than for aluminum to ensure clear edges.It is suggested that when new equipment is obtained, a test method be used (for example, with a speed of 50mm / s per step) to find the best speed range.

The hidden value of maintenance.

The cleaning cycle of the mirror has a direct impact on the quality of the work produced.Actual tests show that after 200 hours of continuous operation, a mirror that has not been cleaned will cause a loss of more than 8 % of the laser's energy.When cleaning, use a professional cleaner, and wipe in one direction only with a cotton swab. Never wipe in circles. This is hard-won experience from a master craftsman.

It was the software algorithm that made the difference.

Most mainstream control software now supports path optimization algorithms.Tests show that with the "smart corner speed reduction" function turned on, the problem of overburning at sharp corners is reduced by 75 %.If you're cutting a logo with a curved line, it's best to set the interpolation precision to 0.01 mm. The job will take 15 % longer, but the end result is worth it.