Steering the beamOf the available marking technologies, beam-steered laser marking systems provide users with the greatest amount of image flexibility in a fast, permanent, noncontact marking process. As manufacturing processes become more automated and after-sale tracking more prevalent, laser markers are frequently the only method available to produce individually unique, permanent images at high speed.
Beam-steered laser marking systems usually incorporate either a CO2 or Nd:YAG laser. The CO2 laser emits a https://terapia24.hu/bemer-keszulek-reszletre/ continuous-wave output in the far-infrared (10.6-um wavelength) while the Nd:YAG laser emits in the near-infrared (1.06 um) in either a CW or pulsed mode (1 to 50 kHz). The Nd:YAG laser is also unique in its ability to produce very short, high-peak-power pulses when operated in the pulsed mode. For example, a typical 60-W-average-power Nd:YAG laser can produce peak powers on the order of 90 kW at 1-kHz pulse rate.
The delivery optics consist of either a simple focusing lens assembly or a combination fixed upcollimator and flat-field lens assembly. In either instance, the laser beam is directed across the work surface by mirrors mounted on two high-speed, computer-controlled galvanometers.
The simple focusing assembly offers the advantages of low cost and fewer optical components and is routinely used with CO2 lasers. The flat field lens design, though more expensive, maintains the focal point of the marking beam on a flat plane for more consistent image characteristics throughout the marking field. The flat-field lens also produces higher power density on the work surface than the simple focusing assembly due to the shorter effective focal length. The flat-field lens design is always preferred for high-accuracy and high-image-quality applications and is usually incorporated with Nd:YAG lasers.