Take laser marking, for example.
If your laser isn’t properly focused on the work piece, the marking will be the wrong shade or even completely ineffective.
However, keeping your laser in the correct focus is easier said than done. For instance, if the work piece isn’t totally flat the laser must be programmed to a different z-distance all along the work piece. There are two common ways to do this:
Most often, it’s based on a CAD file. The problem is that this requires an expert in reading CADs and programming the laser to move in three axes. Also, CAD files aren’t always available – e.g., if the part needs to be repaired.
When not using a CAD file, the other solution is usually to measure ahead of the laser with 2 or more cameras or use a triangulation sensor. This method doesn’t provide real-time feedback on the laser’s focus, which for instance could be used to check (in real time) if the marking was sufficiently deep. Cameras and triangulation sensors also can’t measure sharp angles or deep holes.
There is one solution that can provide laser autofocus without any of these issues:
Optimet’s collinear optical distance sensors work through the same lens as the laser to provide true real-time focus measurements.
Benefits of Collinear
For more details on laser autofocus, read the full article here.