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Author: Atika M. Nyamoti
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
![classification of scanners kcse computer notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEinRRbvSGuhxUwIjqHlHgkcOlj-BPsxu0BBGgYdUrvnDV-TJG2lOHtI5bXegAG9NPvnStqP8XXMv4okQ-Wlku30vckfz2WMmTE8bMKQhe4NbFbXhCqfT8UdwylMNeGm3BS3Zum-KngKT2Y/s1600/classf.JPG) |
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.
![Examples of optical scanners Kcse computer studies notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi3zEFNuCP0X7jMknWctNdH32Dqx2ULLbCBNkWUKfFvtOptSzh2nhYKXb9Fw5ioDBYI3-Xte3nb_EZYe2lGnoZN_EyQfkOFimEz0Q1KuvDscQX4MhuBI7rHle6ypMX7_ppqIVFtr4zGick/s1600/scanners.JPG) |
Examples
of optical scanners
|
![Barcode and scanner types kcse computer studies notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAug32CAXLg7mqUEMXuxjAeH8-PRVvMsSAfrWdbZ5xwgla1Mf0Y8S3IJmKRI9wtnmnjqzGrcp1xizKazdA-dV3QbQRRGB138YZMvPTm6MClaLPmCj7BO_bDjGQ3yFD_kqnUT6MM0AOlsM/s1600/scan+dev.JPG) |
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
![MICR kcse computer notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhS84Skrr_fsixdaPjZKh0G3BBQCinXU0PtJYRZi7Y4nk-Xkxp95Ev9TpeX1VtnYZQQRbghNzDXflvt3_aDfRXcU1kIysw4ZwA6xFR8JUeYo2pNZVdrGvdX8KDYGFc-c7Y7vjmLYWpw7EA/s1600/micr.JPG) |
Magnetic Ink Character Recognition (MICR) |
![Inked Characters kcse computer studies](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiMq1W7pxvW7AZ4lZQpOM0v9aq18FnfDR80EwC24Two0hx5M4sA4tCRkHkiqDRc4nxHG6_IwlrOiryuPXNAucWQCihJB0TQvMBKd-jI0vXyReFWqHEppeBNYiWiJwoZSqD1KraN9Xyx3i0/s1600/inked+characters.JPG) |
Inked Characters |
Card Readers
A magnetic card reader is a device which reads information contained in a encrypted sequence on a magnetic strip
![Card Reader computer KCSE notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi_2ur4GB1xlQCtcUQWHZZFfT88HyH3fFa6eJmF9MBYWikclIgtaQNlpWgftXarEG7NgtY8-k6gvyVdGzft99sLNihx4LaJ3T3RuxU_FUvBb8mc19e4GJqzHVdYroISiOrWU0ke5PvGjMA/s200/card+reader+magnetic.jpg) |
Card Reader |
Digitizers
Also known as graphic tablet, allows a user to
draw an image using a stylus
![Digitizer and a Stylus computer notes kcse form 1](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgEiknz0hRPP7pgXevF7jsk7iq8MgyjJrk0uhp6i3R_3FhQgbhoAq6Dy29n1AT3B8_pGdWR55M6dZr4PMu-E3IaFPnX-6MnWNHsKNf3xibk0uNpWTM4HtlQG1MsBfCGQXC6AQGMRN6bhDg/s1600/digitizers.jpg) |
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
![Digital Camera form 1 computer notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjS7g-R8-Hi7hyO7IezxbY_qVgqBULWLtjtqyolDQH6-6N-pTel6iz-KURGtvriik693RXUWH2D-pHGgvg23qn5U6LIQJOCR3-hrDZ5gYHx-LbsjFApj9wGloZjTx2aW8sFmJuX8HOH0JQ/s1600/digicam.jpg) |
Digital Camera |
Touch screen
It is an electronic visual
display that can detect the presence and location of a touch within the display
area.
![Touch Screen form 1 computer notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj07Ww6SVFsnCSPOnxa3GFojbrpmGuDkdjoyPiWdrFDOj91SvdcE-9POEX1s61BJadaBc4CYRI4KOvTnVKmBoYqCGJZAgWK_xyTtYrnwSriHHoCTzMG9F01psjne50b_s9U7-JX70tqgA4/s1600/touch+screen.jpg) |
Touch Screen |
Voice input
Also known as speech recognition
(SR). Is the translation of spoken words into text.
![Speech recognition form 1 computer notes](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYpiv9KIOqNOlKKSfQcrCECQuDhRBh3J26daMZ72l36vk848jWE24HPquaSHa-PDJh20zGYh3PjeZOf_6QnUJryefD3jbeaXfDk4-OPKnbgwQPrl6yVUOrqCY0xROsk6K8vhAGfYcxRJ4/s1600/voice+dev.JPG) |
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.
![interactive white board form 1 kcse computer tutorials](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_PVjwyQIfeaJIoF5OgLOfhuP4Dr8d4kTzod47xxnTDhChNNfVruvRhthu-wA6UP0lYwVyZ7yEk1H88N6oX6z1O_NoZncFGB1_4Nq2Ji6JeHmsZ016hyFlG9WFBzAFzUCiuZNB0w2BxRo/s1600/iwb.jpg) |
IWB |
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