A 1D sensor is sufficient if you want to measure the height of a part that moves on a conveyor. You could use a distance sensor that has a single laser point to measure the distance from the sensor to the surface. A single laser point is displayed on a surface and most of the time, triangulation is used to get the distance value. So it is only possible to get data for one axis with this kind of technology.
Another type of 1D sensor is a line-scan camera. It can also be used for inspections.
2D Laser Scanners
Structured Light Sensors
This type of sensor will project some sort of structured light pattern onto the part and analyze the light patterns as they are being projected. Usually, two 2D cameras are used to analyze the structured light pattern. Then, algorithms combine the data to create output information.
Time of Flight Sensor
This technology is basically illuminating the part to be measured and measuring the time that it takes for the light to travel to the object and come back to the camera sensor. These are usually less accurate systems.
>>Read more by Amanda Lee, Robotiq, November 9, 2016