Output Devices of Computer

Output Devices

Output devices are used to give output information, data, sound, and display to the user of the computer. Some Output devices are listed here.

  1. Monitor.
  2. Printers.
  3. Projector.
  4. LCD Projection Panels.
  5. Computer Output Microfilm.
  6. Speakers.
  7. HeadPhone.
  8. Visual Display Unit.



Monitors, commonly called Visual Display Unit (VDU), are the main output device of a computer. It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels.
There are two kinds of viewing screen used for monitors.

  • Cathode-Ray Tube (CRT)
  • Flat-Panel Display

Cathode-Ray Tube (CRT) Monitor

The CRT display is made up of small picture elements called pixels. The smaller the pixels, the better the image clarity or resolution. It takes more than one illuminated pixel to form a whole character, such as the letter ‘e’ in the word help.

A finite number of characters can be displayed on a screen at once. The screen can be divided into a series of character boxes – the fixed location on the screen where a standard character can be placed. Most screens are capable of displaying 80 characters of data horizontally and 25 lines vertically.

Flat-Panel Display Monitor

The flat-panel display is divided into two categories −

  • Emissive Displays − Emissive displays are devices that convert electrical energy into light. For example, plasma panel and LED (Light-Emitting Diodes).
  • Non-Emissive Displays − Non-emissive displays use optical effects to convert sunlight or light from some other source into graphics patterns. For example, LCD (Liquid-Crystal Device).


A printer is an output device, which is used to print images, data, and information on paper.

There are two types of printers −

  • Impact Printers
  • Non-Impact Printers

1. Impact Printers: Impact printers print the characters by striking them on the ribbon, which is then pressed on the paper.
These printers are of two types −

  • Character printers
  • Line printers

Character Printers

Character printers are printers that print one character at a time. These are further divided into two types:

  • Dot Matrix Printer(DMP)
  • Daisy Wheel

2. Non-impact Printers: Non-impact printers print the characters without using the ribbon. These printers print a complete page at a time, thus they are also called Page Printers.

These printers are of two types −

  • Laser Printers: These are non-impact page printers. They use laser lights to produce the dots needed to form the characters to be printed on a page.
  • Inkjet Printers: Inkjet printers are non-impact character printers based on relatively new technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high-quality output with presentable features.

Both Input-Output Devices:

  1. Modems
  2. Network cards
  3. Touch Screen