Scanning Devices

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3. Scanning Devices

  • -These are devices that capture data directly into the computer.
  • -They can also be defined as devices that use a magnetic or photo-electric source to scan and convert images into electric signals that can be processed by an electronic apparatus, such as a computer.

Uses of Scanning Devices

Scanning devices are commonly used to:

  • -Convert a text document into an electronic file;
  • -Convert a photograph into an electronic graphic file;
  • -Sense an image to be sent over a voice frequency
  • -Circuit, such as a fax machine;
  • -Reproduce text and images, as with a copier.

 Classification of scanning devices

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Scanners are classified according to technology used to capture data namely: optical and magnetic scanners.

 Optical scanners

These scanners capture data using optical or light technology.
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Examples of optical scanners

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Bar Code and Scanner types

Magnetic scanners

 These scanners use magnetic technology to capture handwritten and magnetic strip data. E.g. MICR (magnetic ink character recognition), card readers etc 

MICR-Magnetic Ink Character Recognition

these scanners are used to read characters written using magnetic ink as shown left. Mostly used in banks to read cheques

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Magnetic Ink Character Recognition (MICR)
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Inked Characters

Card Readers

 A magnetic card reader is a device which reads information contained in a encrypted sequence on a magnetic strip
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Card Reader


Also known as graphic tablet, allows a user to draw an image using a stylus
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Digitizer and a Stylus

 Digital camera

Also known as a digicam. Is a camera that takes video or still photographs by recording images on an electronic image sensor

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Digital Camera


Touch screen

It is an electronic visual display that can detect the presence and location of a touch within the display area.
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Touch Screen

 Voice input

Also known as speech recognition (SR). Is the translation of spoken words into text.
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Voice Input

Interactive Whiteboard (IWB) 

It is a large interactive display that connects to a computer and projector. A projector projects the computer's desktop onto the board's surface where users control the computer using a pen, finger, stylus, or other device. The board is typically mounted to a wall or floor stand.

they are used in a variety of settings, including classrooms at all levels of education, in corporate board rooms and work groups, in training rooms for professional sports coaching, in broadcasting studios and others.
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Basic Computer Practices and Maintenance Skills for Starters –Part two

Definition of a computer

Output devices

Power lines and interfacing in a computer