7.3.2 Scanner Settling Time Compensation |
In an ideal world, galvanometer scanners, and the mirrors attached to them, would have zero mass, and thus be able to decelerate instantly and stop precisely at any commanded position.
Unfortunately, the real world pokes us in the eye with the sharp stick of inertia...
Waiting for the scanner to settle.Real galvanometer scanners have non-zero mass, and thus exhibit inertia. Consequently they take some time to decelerate when they reach the end of a vector.
If they are not critically tuned, the scanners may even overshoot the final commanded position at first, before eventually settling to it in a series of decreasing excursions.
If the next vector happens to be exactly co-linear with the current one, or if scanner is moving relatively slowly, these effects might not be noticable, or at least not represent a qualitative problem.
However, in the far more common case where there is a definite change of direction between vectors, e.g. at a corner, the laser beam may well deviate so far from the intended path that quality of processing is compromised.
We can mitigate these effects by allowing the scanner time to settle to the final position of the current vector before it starts scanning the next one.
For this purpose the SP-ICE-3 Card implements the JumpDelay, MarkDelay, and PolyDelay properties.
Please refer to 7.3.2.1 Selecting Scanner Delay Values for more details.