Image scanner

In computing, an image scanner is a device used to transfer images or text into a computer. There are special models for scanning photo negatives, or to scan books. In the computer, the signal from the scanner is transferred to a digital image. This image can then be edited, printed, etc. All scanners have special parts which are used to take a picture from an object.

Charge-coupled device or Contact Image Sensor parts take the light from the object and change it into a digital signal. The digital signal is then transferred to the computer memory or is read in the scanner's processor. With some software it can be changed to a compressed digital image, like JPEG or PNG. Text printed or written by hand can be changed to ASCII code by an OCR program.

 Types 
The main types of scanner 
Desktop scanner (flatbed scanner). This is probably the most popular type. An object to be scanned (picture, image, text sheet) is put on the glass. Under the glass, there is a moving Image Sensor.
Hand scanner. The device is moved on the paper by hand. It was popular during the 1990s. 
Rotary scanner (drum scanner) used for fast scanning large numbers of sheets of paper.
Smartphone scanner scans a document by taking a photo with the smartphone's camera.

 Producers 
 Canon
 HP
 Lexmark
 Mustek
 Plustek
 Other

 References 

Related pages
 Digital camera

 Other websites 
 Scanning tips
 More tips on scanning 
 HP scanning

Category:Computer hardware
Category:Data input