Feeding, printing, collecting operation are done automatically, however these features vary in the different makes of machines.
The machine works on its own but the feeding and collecting has to be done by hand.
These beams may be emanating from laser, or the spray of ink, the most important factor is that the product or machine should be moving at constant speed.
The moving product are sensed by a sensor & give a signal to the machine which responds immediately with the printing.
A few machines in this category are Inkjet printer, Laser printer, industrial Inkjet coding machine, laser marking systems.