Types Of Computer Hardware – Output Devices(Print – Printer)


Devices that produce text and graphics on a physical medium such as paper or transparency film are referred to as print output hardware. These are printers and plotters, which are available in different types.

Printers can be classified according to many features but the most common is the print technology. Two popular print technologies used by printers to print their information on paper are impact and non-impact technology. Impact printers and non-impact printers are developed for various types of printing tasks.

Are there other different types of printers?

Sure! there are. These are Plotters and Special Purpose printers which will be looked at in the next post.


Impact Printers

An impact printer makes use of mechanical impact to print its output on a paper. In other words, with an impact printer the print mechanism actually makes direct contact with the print medium. It prints with extended pins on the print head making direct contact with the paper. An image or character is formed on the paper when the appropriate pins are striking on an inked-ribbon against a paper. Dots of ink are transferred onto the paper and with the movement of the print head the appropriate image is formed.

There are different types of impact printers and the common ones include:

  • Line Printers
  • Dot-Matrix Printers
  • Daisy Wheel Printers
Line Printers

Line PrinterLine printers print information on the paper line by line with each character composed of group of tiny lines. They can print 300 to 3000 lines per minute and they are larger and more expensive. Line printers can use different types of papers. Some of them include continuous form sheets, cards, envelopes, foolscap sheets and A4 or A3 size sheets.

Dot-matrix Printers

Dot-Matrix PrinterDot-matrix printers print characters in dots. The print is produced by a small print head that moves to and fro across the page and strike a ribbon against the paper with an array of wires. Their print speeds are from 100 to 700 characters per second. They usually produce draft quality prints and are less expensive. Dot-matrix printers can use many types of papers just as used by line printers.

Daisy Wheel Printers

Daixy wheel PrinterThese are impact printers fitted with exchangeable print heads called daisy wheels. To print each character, the wheel is rotated and the appropriate spoke is struck against an inked ribbon. Printing speeds are typically 45 characters per second.


Non-impact Printers

Due to tremendous improvements in the printer industry over the years, most printers today are non-impact printers, meaning they form images without the print mechanism actually touching the paper. Non-impact printers usually produce higher quality images and are much more quitter than impact printers.

Two most common printers today are laser and ink-jet printers and they are all non-impact printers. Different types of non-impact printers are below:

Laser Printers

Laser printers use the print technology similar to the photocopier machine. To print a document, the laser printer first uses a laser beam to charge the appropriate locations on a drum to form the page’s image, and uses a rotating mirror to draw an image of the desired page on a photosensitive drum. The toner (ink powder) is then releaseLaser Printerd from a toner cartridge and spread to the drum. The toner is then transferred to a piece of paper when the paper is rolled over the drum. A heating unit fuses the toner powder to the paper to permanently form the image. Laser printers use buffers that store an entire page at a time and so they print one page at a time. If a whole page is loaded, it will be printed.

They are typically faster and have better quality output than ink-jet printers. Many home-use laser printers can print between 15 to 30 pages per minute. However, they can be faster and print approximately 21,000 lines per minute, or 437 pages per minute if each page contains 48 lines.

Ink-jet Printers

Ink-jet printers work in the same way as dot-matrix printers. They create images or characters with little dots by firing streams of ink drops at the surface of the paper from one or more banks of tiny nozzles, and the ink is absorbed intoInkjet Printer the paper and dries instantly and various colors of ink can also be used. This is achieved by surface boiling of ink using tiny electric heating element behind the nozzle or by mechanical pressure.

Ink-jet printers print out finer characters than dot-matrix printers. They use colour ink cartridges of four colours: cyan (blue), magenta (red), yellow and black as their source of ink when printing. Their printing speed is about 5 to 60 pages per minute.

Thermal Printers

Thermal PrinterThermal printers use heat as a mechanism to print information character by character. The image is produced by localized heating of paper that has a very thin heat sensitive colour coating containing two separate and colourless components. When heated the colour melts and combines with colourless dyestuff to make a visible mark. They however do not produce good quality output like laser printers.

Electrostatic Printers

These are obsolete type of printers that produced images by passing electric current into the surface of specially prepared paper. They assemble a whole page of information before printing. These printers are offshoot of photocopiers. They use toner as their source of ink and have their own processor and memory. This therefore makes it possible to print in many typefaces or fonts.


If you liked this article and find it helpful, please feel free to share and don’t hesitate to ask any question or share your thoughts or experiences in the comments section below.

You May Also Like

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.