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Digital Scanners

Scanners That Can Read

Scanning artwork and photographs for reproduction is only one reason to use a digital scanner. Another important use is to enable computers to read printed documents. This process is called optical character recognition.

In optical character recognition, a black-and-white digital scan is first made of a document. Using various software programs, a computer is able to recognize this image as various letters and words. The text can then be edited in a word-processing program, just like text typed in by a person at a keyboard.

Because converting paper documents to digital format is very important to many businesses; some scanners have been made for this specific purpose. The primary technology is the same as for desktop scanners, but these special scanners use a mechanism that feeds pieces of paper one-by-one onto the scanning plate.



Chambers, Mark L. Scanners for Dummies. Hungrey Minds Inc., 2001.

Lew, Michael S. Principles of Visual Information Retrieval (Advances in Pattern Recognition). Berlin: Springer Verlag, 2001.


PC Tech Guide. "Input-Output Scanners." December 1, 2001 [cited January 17, 2003]. <http://www.pctechguide.com/18scanners.htm>.

Scott M. Lewis


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Digital code

—Binary code, the series of ones and zeroes that make up all information used by a computer.

Halftone screen

—Pattern of minute dots that defines a color or a black-and-white tone on a printed page.

Light sensor

—Device that translates light into an electric current, the stronger the light the stronger the current.

Optical character recognition

—Process in which a typewritten document is scanned as an image, and translated into words using computer software.


—The smallest unit of color or tonality in a digital image; a single point.


—The number of pixels a scanner can read per square inch.

Additional topics

Science EncyclopediaScience & Philosophy: Jean-Paul Sartre Biography to Seminiferous tubulesDigital Scanners - The Scanning Process, Color Scanning, Digital Scanners For Publishing, Scanners That Can Read