Computers Science Engineering (Computer Component) - OUTPUT DEVICES

 

 

2.0 The Output Devices :

The output  unit is responsible for producing the output in user readable form. Various output devices like monitor (also called VDU i.e Visual Display Unit), printer, plotter etc.make the output unit of computer.

The function of an output unit is to present processed data to the user.The computer sends the output to monitor if the user needs to see the output. The sound output is produced with the help of speakers. Graphic output is produced with the help of plotters.

Output Devices  :

Mainly  there are three principle devices to output information form a computer. These are : printers, video terminals and speakers.Let us examine each of them individually.

2.0.1  Monitors :

Monitor (" Screen") is the most common form of output information in similar way to that shown on a television screen. The picture on a monitor is made up of thousand of tiny coloured dots called pixels.

The two most common types are a Cathode -ray-Tube (CRT) and a Liquid Crystal Display(LCD) monitor.

2.0.2 Printer :

Printer is an output device used for creating paper copies of output from the computer .Printers can produce text and image on paper.

Printers can be divided into two distinct categories:

1. Impact printers. In these printers , there is mechanical contact between the print head and paper.

2. Non-impact printers. In these printers, there is no mechanical contact between the print head and paper.

Impact Printers :

Dot Matrix Printer :

Non Impact Printers:  The natural limitations of speed in electromechanical  devices and cost considerations have led to the development of printers called non-impact printers.

1. Inkjet Printers : An inkjet printer that fires extremely small droplets of ink to create impression of text or image.

2. Laser printer :  These printer print in the same way as photocopies do.The powered ink (i.e toner) is transferred to paper  to form a text/image pattern.

 2.0.3 Plotter :

Many applications require a graphical output apart from printed output. e.g pie chart, bar chart etc.

2.0.4 Speakers : Speakers receive the sound in form of electric current from the sound card and then convert it to sound format.