galvoohjatut

Galvo-ohjattu (galvanometer-based) refers to a class of systems that use galvanometer-driven mirrors to steer a light beam, most commonly a laser. In Finnish technical literature the term galvoohjatut describes devices where the angular position of one or more mirrors is controlled in real time to translate a beam across a target plane. These systems are widely used in precise beam steering applications such as marking, engraving, laser projection, and fast optical scanning.

Operating principle: A galvanometer motor rotates a small mirror mounted on a low-inertia shaft. The rotation angle is controlled by a pair of coils and a magnetic field, typically in a closed-loop configuration with an angle encoder or resolver to achieve high accuracy and repeatability. Most setups use two perpendicular galvo axes (X and Y) to provide two-dimensional scanning. The optics, including telecentric lenses and possibly an F-theta lens, are chosen to map angular deflection to a nearly linear scan across a working plane. The system can produce various scan patterns, from raster-like sweeps to continuous vector paths, and work at high speeds limited by mirror inertia and mechanical resonance.

Applications: Galvo systems are central to laser marking and engraving, micro-machining, precision cutting, laser projection and display, and high-speed optical scanning in measurement equipment. They enable precise, repeatable beam placement over a defined field of view.

Advantages and limitations: Benefits include high scan speed, precision, compact form factor, and good repeatability. Limitations involve a finite field of view determined by mirror size, optical distortion and nonuniform intensity across the field, resonances at high frequencies, and wear or drift in the mechanical components requiring calibration and maintenance.