Scanner

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

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

Type of scanners:
Flatbed scanner: The flatbed scanner is most common desktop scanner. It resembles the copy machine. In the flatbed scanner, the item being scanned resets on a glass plate while 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.

Sheet fed scanner: Personal sheet fed scanner have gained popularity during last few years. These devices are more like a fax machines, because they move the page being scanned past the scanning head, rather than the other way around. The main difference to flatbed scanners is that the image sensor does not move but the document itself is pulled past the mounted image sensor.

Hand held scanner: The hand held scanner is a scanning device where the scanning element is built into a small hand held unit. The hand held unit is then waved or rolled over the item being scanned.
Many scanners are available now a days that 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 program using computers and in desktop publishing. Businesses use scanners for storing documents on the computer.