They spray ink on the page by using a reservoir of ink, a pump, and an ink nozzle. The spraying of ink forms a pattern onto a page as per data to be printed. They are the most commonly used printer and range from small cheap consumer models to very large professional machines.
The inkjet printer works by propelling ink onto various sizes of paper. Many inkjets store ink in multiple ink cartridges that are consumable; they have to be replaced when empty. Some inkjet printers stop operating if just one of the ink cartridges is empty. Two common types of inkjet printers are the thermal inkjet and the piezoelectric inkjet:
Inside the ink cartridge are several small chambers. At the top of each chamber are a metal
plate and a tube leading to the ink supply. At the bottom of each chamber is a small pinhole.
These pinholes spray ink on the page to form characters and images as patterns of dots with much higher resolution. There are two methods of spraying the ink out of the cartridge.
Thermal inkjets: When a particular chamber needs to spray ink, an electric signal is sent to the heating element, energizing it. The elements heat up quickly, causing the ink to vaporize. Because of the expanding ink vapor, the ink is pushed out the pinhole and forms a bubble. As the vapor expands, the bubble eventually gets large enough to break off into a droplet. HP and Canon develop many models of thermal inkjet printers. They are different from with thermal printers.
Piezoelectric inkjets: It uses a piezoelectric element that flexes when energized. The outward flex pushes the ink from the nozzle and forcing the ink onto the paper. This process enables longer print head life as compared to thermal inkjets. Epson makes piezoelectric inkjet printers.
Parts of a Inkjet Printer
Printhead/Ink Cartridge – It has many small nozzles (usually 100–200) that spray the ink in small dots onto the page, usually it is part of the ink cartridge, which contains a reservoir of ink and the printhead in a removable package. Some printers have multiple printheads, one for each color. It must be replaced as the ink supply runs out.
Head Carriage, Belt, and Stepper Motor – Printhead carriage moves back and forth during printing and contains physical and electronic connections. These connections cause the nozzles to fire. The stepper motor and belt make the printhead carriage move. Stepper motor is an electric motor to move the printhead carriage. The belt is placed around two small wheels or pulleys and attached to the printhead carriage and is driven by the carriage motor and moves the printhead back and forth across the page while it prints.
Paper-Feed Mechanism – It picks up paper from the paper tray and feeds it into the printer. It has several smaller assemblies and has pickup rollers, separator pads and a paper tray.