Inkjet Printers - History And Technologies
By Kishor Nayak on Dec 19, 2008 in Hardware | comments(0)
Although Ink Jet printers only appeared on the consumer market in the late 1980s, they had been under development for more than twenty years by that time. In the mid-1970s, printer companies realized the potential of the technology that would make dot matrix printers obsolete.
The challenge, however, was to come up with a way to create an affordable Ink Jet printer that would reliably create high-quality printouts.
Technical challenges
The quality of the printed page depends largely on the relationship between the ink, the print head, and the paper. Researchers had a hard time creating a controlled flow of ink from the print head onto the page, and preventing the print head from becoming clogged with dried ink. Once these challenges were met by Canon and Hewlett Packard in the late 1980s, liquid Ink Jet printers began to come on the market.
Different styles
Continuous Ink Jet printers were developed by IBM, and use electrically-charged droplets to coat the page with ink very quickly but also waste a lot of ink. This technology never caught on with consumers, but is used today in industrial settings, for labeling cartons and addressing direct mail. The more popular design among consumers is the drop-on-demand Ink Jet printer, invented by Siemens in 1977. These printers, which spray ink only where needed, are slower than continuous Ink Jet printers but less expensive.
Most drop-on-demand printers, including those made by HP, Canon, and Lexmark, use thermal technology to push the drops of ink out of the print head; Epson uses its own technology, called piezo-electric, to achieve the same effect. The Ink Jet printer has come a long way since it became available almost twenty years ago: Hewlett Packard’s DeskJet printer, which was among the first available to the public, was priced at $1,000 in 1988!
If you’re like most Ink Jet printer owners, you only look inside your printer when the printer ink cartridge needs to be replaced. But the ink cartridge is just one element of a pretty complex mechanism — let’s take a look inside your Ink Jet printer.
The print head
At the heart of your Ink Jet printer is the print head, which houses the nozzles responsible for spraying the ink onto the printer paper. Some printer manufacturers now build the print head into the ink cartridge, so as to keep the price of the printer itself down, and to increase the lifetime of the printer.
The print head and ink cartridges (together, called the print head assembly) are pushed back and forth across the page by the stepper motor. The print head assembly travels across a stabilizer bar, to ensure even and precise motion.
Rollers
Paper is pulled into the printer from the paper tray or feeder by a pair of rollers, which control the rate at which the paper advances past the print head assembly. The rollers are powered by the paper feed stepper motor.
Twin Ink Jet technologies
Most Ink Jet printer manufacturers (including HP and Canon) use thermal bubble (bubble jet) technology to transfer ink to the page. In these printers, tiny resistors heat the printer ink to form bubbles. As these bubbles pop, ink is fired onto the page.
Some other Ink Jet printers, including those manufactured by Epson, use piezoelectric technology instead. This technique involves a piezo crystal, housed in the ink reservoir of each nozzle, which is stimulated by an electric charge. That charge causes the crystal to vibrate, forcing ink out through the nozzle in which it is located.
