Ink jet printer

Sponsorship the way you would do it

Ink jet printers are the most common type of computer printer, and are also used extensively for special-purpose applications in industry and commerce. For example, many ATMs, stock control systems, and cash registers use an injet printer.

In the personal and small business computer market, injet printers are easily the most common type. Injets are usually inexpensive, quiet, reasonably fast, and many models can produce high quality output.

Like most modern technologies, the present-day inkjet has built on the progress made by many earlier versions. Among many contributors, Hewlett-Packard and Canon can claim a substantial share of credit for the development of the modern inkjet. On the worldwide consumer market, four manufactures account for the majority of injet printer sales: Canon, Hewlett-Packard, Epson, and Lexmark.

Most current inkjets work by having a print cartridge with a series of tiny electrically-heated chambers that are constructed by photolithography. To produce an image, the printer runs a pulse of current through the heating elements. A steam explosion in the chamber forms a bubble, which propels a droplet of ink onto the paper (hence Canon's tradename for their inkjets, bubblejet). When the bubble condenses, surplus ink is sucked back up from the printing surface. The ink's surface tension pumps another charge of ink into the chamber through a narrow channel attached to an ink reservoir.

Older ink jet printers directed ink streams electrostatically or piezoelectrically; ultrasound was used to induce waves in the ink, which then broke into little droplets that would fall on the right place on the page.

Compared to earlier consumer-oriented printers, ink jets have a number of advantages. Compared to dot matrix or daisywheel printers, they are almost silent. Many are able to produce high resolutions, and color printing of excellent quality is widely available.

The disadvantages of inkjets include flimsy print heads that are prone to clogging, and ink cartridges that are expensive, sometimes costing US$30–$40 or more. This typically leads value minded consumers to consider laser printers for medium to high volume printer applications.

There are two main design philosophies in injet head design. Each has strengths and weaknesses.

The fixed-head philosophy provides an inbuilt print head that is designed to last for the whole life of the printer. Because the head need not be replaced every time the ink runs out, consumable costs are typically lower and the head itself can be more precise than a cheap disposable one. On the other hand, if the head is damaged, it is usually necessary to replace the entire printer. Epson have traditionally used fixed print heads.

The disposable head philosophy uses a print head which is part of the replacable ink cartridge. Every time the printer runs out of ink, the entire cartridge is replaced with a new one. This adds to the cost of consumables and makes it more difficult to manufacture a high-precision head within reasonable cost limits, but also means that a damaged print head is only a minor problem: the user can simply buy a new cartridge. Hewlett-Packard and Canon have traditionaly favoured the disposable print head.

A few printers (including certain Olivetti and Fujitsu models) have used an intermediate method: a disposable ink cartridge mounted on a disposable head, which is replaced infrequently (perhaps every sixth ink cartridge or so). These were not a great market success.

A common business model for ink jet printers is to sell the actual printer at or even below cost, while significantly marking up the price of the (proprietary) ink cartridges. Hewlett-Packard, for example were recently able to cover the entire 12-month losses accumulated by their other division with the profits made by their consumables division, and have a little left over.

Alternatives for consumers are cheaper copies of cartridges, produced by other companies, and refilling cartridges themselves, for which special refill sets are for sale.