Computer Scanner and Printer

                            
Computer Scanner
Computer  Scanner  creates  an  electronic  copy  of  a  photograph  This  process of creating a picture - file from a photograph is called as  scanning  or  digitization .  the scanned image can be opened in any  suitable  program  for  editing  and can be edited. A hand held scanner  is  to  be  scanned , just like barber moves the hair pricker over  the  head .  In  sheet  fed  scanner, you are required to feed a single sheet of paper to be scanned. In  flat bed scanner, just place the  paper  to  be scanned over flat bed. If a page in a book is to be scanned , then  you  can not use sheet fed scanner, you should use flat  bed  scanner . If a large sized map is to be scanned, then hand held  scanner  should  be used .  so  this  is  all about the computer scanner.

Computer Printer
A Computer Printer is used for drawing printouts. As a PC user you will use one of the following printerrs (a) dot matrix printer (b)  ink jet  printer ,  and  ( c )   Laser   printer .  In  big   companies ,  where thousands  of   pages  are  to  be  printed ,  line  printers   are  used Operating  cost of line printers is least. However, You can not print  graphics  using  line  printers .  Also ,  line  printers  come with very impressive   price  tag .  in   order   to  print   engineering  drawings plotters  are  used .  Operating cost of plotters is high, so also their price. But plotters are a must for  high quality engineering drawing printouts. Technically, 

printers are classified into two groups.
(1) Impact  printers .  For  example ,  dot  matrix  printers  and  line printers.
(2)  Non  impact  printers  .   For  example  ,  inkjet  printers ,   laser printers, plotters, and image setters.
Impact  printers make noise, where as, non-impact printers do not make much noise .  Price  of  dot  matrix  printers is moderate, and the quality of printouts is  poor ,  but  operating cost is lowest. Dot matrix printers come in two varieties - 9 pin and 24- pin. More the pins ,  more  the  resolution, better the quality of printout. price of inkjet  printers   is  moderate  but  operating  cost  is  high, and the quality  of  printouts  is  good .  Price  of  low  end  laser  printers  is moderate ,  their  operating  cost  is low, and quality of printouts is good. so friend this is all about the computer printer.