The TTL laser and the image-processing vision sensor share one and the same optical path ("Through-The-Lens"). This coaxial principle allows seamless switching between camera and laser. As this concept does not involve an offset between the two sensors, no loss of measuring range in the X-direction occurs and calibration is minimised.
As the rapid autofocus sensor, the TTL laser uses the laser light reflected from the surface of the inspected object to find the best focus position for the vision sensor. The distance to the inspected part's surface is determined by triangulating the reflected light and used for the camera's vertical track. The TTL laser clearly accelerates the focusing process in comparison with conventional video focusing techniques, while achieving good reproducibility values. The result is an overall faster measuring speed and therefore a higher inspected parts throughput.
The TTL laser can perform height measurements using a combination of focus points at different levels on the part, while at the same time measuring the depth of the even the smallest of blind holes using the coaxial principle.
Scanning is a further application of the TTL laser. With a high measuring point density of up to 350 points per second, the sensor is capable of capturing the profile of freeform surfaces in a non-contact and therefore non-destructive manner.
Example applications for the TTL laser:
- Quick focusing of the vision sensor
- Precise measurements of heights, hole depths and flat surfaces
- Contour and surface scanning