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Output Devices

                 Output is the information obtained after processing of data. The user receives the result through
                 output devices. Output can be in the form of soft copy or hard copy. Soft copy refers to the
                 digital copy which lies in the storage device where as hard copy refers to the printed contents on
                 a paper or film. Some of the output devices are:

                 •   Monitor: Monitor is a standard output device. It is also known as VDU (Visual Display Unit)
                   or Screen. Monitor is used for interactive processing i.e., the data being fed is displayed on
                                 the screen. It resembles a television. The images that you see on the monitor
                                 are made up of tiny dots called pixels. The clarity of the images depends on the
                                 number of dots/pixels per inch on the screen. The maximum number of dots per
                                 inch (dpi) will give you more clarity and a better display.

                   Nowadays,  monitors with Light Emitting Diode (LED)  screens have become very popular
                    because of the clarity of the images and the slim shape of the monitor.
                 •  Printer: Printer is a common output device which is used for the purpose of printing documents.
                   Printer generates a hard copy of data or information. Printers are categorised into impact or
                   non-impact depending on how they work. Impact printers prints the contents by striking
                   the printer head or needle, on an ink ribbon which rolls through the cartridge to make mark
                   on the paper. Non-impact printers create an image on paper by spraying ink on the paper.
                   Some of the common printers are:
                      ◦ Dot Matrix Printer

                      Dot  matrix  printer  is  the  most commonly used printer.  It  is also
                      known as the ‘Wire Matrix’ printer. In dot matrix printer, the printer
                      head contains a matrix of pins. The characters are printed by dots
                      which are formed by striking the pins on the ribbon with the help of small ‘printer head’
                      which moves to and fro across the page and stops momentarily at each character position
                      to strike the print ribbon.
                      A print head of a Dot matrix printer contains 9 or 24 pins. Dot matrix printer is cheaper and
                      has low printing cost than other printers. The width of a dot matrix printer can be 80 or 132
                      or 136 columns. Dot matrix printer can print upto 100 to 300 characters in a second. The
                      resolution of the printing ranges from 150 to 300 dots per inch (dpi).

                                        ◦ Inkjet Printer
                                           Inkjet printers produces a high quality print outputs by spraying drops of
                                         ink (which is stored in coloured and black cartridges). This printer has a
                                         print head which contains the cartridge that has several tiny holes through
                                         which the ink is sprayed on the paper.


                       An inkjet printer can print upto 2 to 10 pages per minute. Its printing is costlier than that
                      of dot matrix printer but its quality is much better than that and it prints at a medium pace.
                      Inkjet printer prints photo quality image with resolution of 400 dpi to 4000 dpi (dots per inch).






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                                                                              Computer—Hardware Components
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