People Counting,Footfall Analytics For Public Space,Retail Foot Traffic Analysis,People Counting Analysis OP Retail (Suzhou) Technology Co., Ltd , https://www.opretailtech.com
Large Format
The concept of large format laser marking originated from the early use of plotter control units directly on laser equipment. At that time, the drawing pen was removed, and instead, a 45° rotating mirror was installed at the X-axis and Y-axis base points, while a small focusing mirror was placed at the original pen position to redirect the light path and focus the beam. This setup allowed for direct operation using standard drawing software, which could send print commands to drive the optical system. One major benefit of this method was its ability to handle large-format marking with relatively low precision, eliminating the need for specialized marking software. However, it had several drawbacks, such as slow speed, limited accuracy, mechanical wear from the pen arm, and poor reliability. Due to these issues, early large-format systems gradually lost popularity in the market. Today, most large-format systems still follow similar principles, but now they are typically driven by servo motors rather than mechanical pens. With the development of high-speed 3D dynamic focusing galvanometer systems, traditional large-format setups are slowly becoming obsolete.
In the era of mirror-based systems, due to the limitations of large-format technology, high-speed galvanometer systems were not widely adopted in China. To address this, some engineers developed a mirror-scanning system driven by stepper motors. The laser beam, after being expanded, is reflected by two gold mirrors mounted at 90°, controlled by stepping motors. The beam is then directed through an F-theta field lens onto the workpiece. As the mirrors move, the laser spot shifts along the X and Y axes, allowing the system to trace straight lines and complex curves. This approach significantly improved speed and accuracy compared to large-format systems, making it suitable for many industrial applications. Although it still lagged behind international galvanometer systems, this design marked a significant milestone in China’s laser technology development. It demonstrated the country's growing capability in designing and manufacturing laser systems. Eventually, with the rise of more advanced systems, this method was phased out of mainstream use.
Galvanometer Era
In 1998, the large-scale adoption of galvanometer scanning systems began in China. A galvanometer, also known as an ammeter, operates on a principle similar to that of an ammeter. Instead of a needle, a lens is used, and the signal from the probe is replaced by a computer-controlled -5V to +5V DC signal. Like mirror-scanning systems, galvanometers use a pair of mirrors to guide the laser beam. However, instead of stepping motors, they use servo motors for more precise control. Additionally, a position sensor is incorporated into the system, creating a feedback loop that enhances accuracy. This advancement significantly improved the speed and repeat positioning accuracy of the entire system.
Currently, domestic laser marking systems can be categorized into three main types based on their working mode: mask marking, array marking, and scanning marking.
Mask marking, also known as projection marking, involves a system composed of a laser, a reticle, and an imaging lens. The laser beam is expanded and projected onto a pre-made mask, where the pattern is transmitted through the mask and imaged onto the workpiece via a lens. Each pulse of the laser creates a complete mark, including multiple symbols at once. This makes the process very fast, especially for high-volume production where marks can be applied directly on the assembly line. However, this method has limited flexibility and lower energy efficiency, as only a portion of the laser beam is used for each mark.