Laser marking systems are laser systems consisting of a beam source, deflection head with optics, control and supply unit, which are offered without protective devices and handling for integration into marking workstations and marking stations. The beam sources used are, for example, solid-state lasers such as Nd:YAG lasers and fibre lasers with wavelengths of 1062-1064 nm or CO2 gas lasers with wavelengths of 930 or 10.6 µm in the mid-infrared range. The laser marking unit always comprises a laser beam source, a marking head and a control and operating unit with marking software.
Depending on the design of the marking head, a distinction is made between vector lasers, dot-matrix lasers and mask lasers. Vector lasers enable freely programmable marking in a specific working field, which can often be changed by interchangeable lenses. Dot-matrix lasers can only mark a matrix of a few predefined points. Mask lasers are used to mark fixed marking contents with the aid of templates.
The selection of the laser marker is usually application-specific by adapting the type and wavelength of the laser, the continuous and peak power and, if necessary, the lenses to the type of marking, the marking field, the workpiece surface and the marking speed. The actual marking is produced with marking heads of different designs.
The most common marking head design for laser marking devices is the freely programmable vector laser. The beam source generates a continuous beam of light that is deflected by mirrors in the marking head and directed onto the workpiece via an optical system. The mirrors are driven by galvanometer scanners consisting of highly dynamic rotary drives and high-precision position detectors. Vector lasers thus offer high accuracy and speed and are suitable for marking stationary or moving objects.
Dot-matrix lasers are divided into single- and multi-laser systems, all of which work with light pulses. Single-laser systems generate light pulses that reach the marking surface via a deflection unit. In multi-laser systems with, for example, seven lasers, each laser is directed at a different angle via fixed optics in a vertical line to a different point on the matrix. Dot-matrix lasers can only produce a continuous mark if the workpiece is moving.
Another option is mask marking, where a laser pulse is passed through the apertures of a stencil and projected onto the marking surface via optics. This process is particularly suitable for marking fixed contents in high quantities and at very high speed.