21.7.13

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

kcse computer studies notes
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)
kcse computer studies
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

 Digitizers


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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IWB


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