What is the working principle of continuous inkjet printing?

Continuous inkjet printers produce a continuous stream of ink, which is ejected from the main ink tank through nozzles and into the ink channel. The ink channel uses vacuum pressure to return unused ink to the main ink tank. This ink stream is continuously segmented (modulated) into individual droplets in a very precise and controlled manner. During printing, the printer applies a different charge to each droplet, causing it to deflect from the ink channel under the influence of a high-voltage electric field inside the printhead, forming vertical lines of ink droplets (strokes). The greater the charge, the greater the vertical deflection of the droplet. A stroke is composed of a series of ink droplets, forming a vertical slice of the character or image to be printed. As the print passes through the printer, it forms subsequent strokes in the correct pattern, thus creating the dots of each character in the dot matrix. The most common "fonts" consist of seven vertical droplets and five horizontal (stroke) droplets. Multiple lines can also be printed at once, and these lines can be stacked on top of each other. Single-line, double-line, and triple-line codes are most common.