Scanner Input Device And Saveral Kinds Of Scanner

Another input device that is being used increasingly is the scanner. Often, there are situations when some information (picture or text) is a available on paper and is needed on the computer disk for further editing. The simplest way to do this would be to take photograph of the image directly from the source, and convert it into a form that can be saved on the disk and then edited.

A scanner scans an image and transforms the image to ASCII codes that is used by the computer to represent the characters you find on you keyboard, such as, alphabets, numbers, punctuation marks and graphics. These can be edited, manipulated and printed.

There are three types of scanners:

Flatbed Scanner: The Flatbed scanner is most common desktop scanner. It resembles the copy machine. In a Flatbed scanner, The item being scanned rests on a glass plate whicle the scanning head moves underneath it. It works like a copy machine except that it creates a file of the document rather than a paper copy.
Sheetfed Scanner: Personal sheetfed scanners have gained popylarity during the last few years. These devices are more like fax machines, because they move the page being scanned past the scanning head. The main difference between this type and a flatbed scanner is that the image sensor does not move but the document itself is pulled past the mounted image sensor.
Handheld Scanner: The handheld scanner is a scanning device where the scanning element is built inro a small handheld unit. The handheld unit is then waved or rolled over the item being scanned.

Many of the scanners available now-a-days are capable of not only scanning text and graphics, but also integrating text and graphics files.

Scanners are used to reproduce photographs on the computer screen. They can be used in training programs using computes and in desktop publishing. Businessses use scanners for storing documents on the computer.