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.
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