Cartridge

A cartridge is the detachable component of a printer in which the ink is usually stored. This ink is used to generate the printout when the relevant command is given. Most printer manufacturers such as Hewlett Packard, Canon, Epson and Lexmark also produce ink cartridges. Most often, due to space and availability constraints, people purchase cartridges of a different brand than the printer. As long as these cartridges are compatible, there should be no functional compromises. Certain cartridges can be refilled, thus being more economical in the long run.

Based on the technology used, cartridges can be broadly classified into two categories; thermal and piezoelectric. In the case of inkjet printer cartridges, as soon as the print command is given, an electric current is passed through a small metal plate located within the ink canister. This causes the metal to heat up and vaporise the ink from the immediate vicinity into air bubbles that pass through the nozzle. When the amount of ink increases, it is spewed out of the nozzle into the paper to be printed. Sometimes, if some dried ink gets collected at the tip of the nozzle, the ink flow gets interrupted. In piezoelectric printer cartridges, the metal plate is replaced by a piezoelectric crystal. Correspondingly, the flow of electricity results in the change in the size and shape of the crystal, forcing the ink out of the nozzle.

Ink cartridges are an extremely useful invention and have drastically improved the quality of printouts. Generally, two cartridges are present in a printer, one containing only black ink and the other having a combination of the three primary colours, red, green and blue. While some cartridges are applicable for printing text content, others are specially made for printing photos.