How Galvo Technology Works
The Core Mechanism
A galvo scanner consists of two small mirrors mounted on precision galvanometer motors:
Each mirror is attached to a galvanometer — an electromagnetic rotary motor that rotates to a precise angle based on the electrical current it receives. The mirrors are incredibly lightweight (typically 8–15 mm diameter, <1 gram), which is the key to their speed.
Here’s the chain of events when the laser fires a mark:
All of this happens in under 1 millisecond for repositioning.
Why Mirrors Beat Rails
The fundamental speed advantage comes down to physics: rotating a 1-gram mirror requires dramatically less force than moving a 5-kilogram gantry head.
| Factor | Galvo Scanner | Gantry System |
|---|---|---|
| Moving mass | < 1 gram (mirror) | 2–10 kg (entire head) |
| Acceleration | Up to 100,000 rad/s² | 1–5 m/s² |
| Repositioning time | 0.3–1 ms | 30–100 ms |
| Mechanical wear | Minimal (no rails/belts) | Significant (linear bearings, belts) |
| Maintenance interval | 20,000+ hours | 5,000–10,000 hours |
The galvo scanner has no belts to stretch, no rails to accumulate dust, and no linear bearings to wear out. It’s an electromagnetic system with minimal mechanical contact.
