Page 21 - Viva ICSE Computer Studies 7 : E-book

is placed on the glass pane. The sensor and source of light move across the glass pane to scan
the document and produce its digital copy. It is a popular desktop scanner. It is used in homes,
schools and offi ces.
Microphone
A microphone is a special multimedia input device that is used to store
voice data consisting of a recorded message or synthesised sound using
a GUI operating system such as
Windows. Microphone is used in Think and Discuss
activities like videoconferencing
and recording. Which type of scanner is most
commonly used and why?
Light Pen
A light pen is a small pen-shaped pointing device, which
contains light sensors. It is used to choose objects or
commands on the screen either by pressing it against the
surface of the screen or by pressing a small switch on its
side. This sends a signal to the computer, which then works
out the light pen’s exact location on the screen.

Digital Camera

A digital camera is very similar to the traditional camera. Digital
camera or webcam is used to capture and store data in the form of
still and video images. It has become very popular on the Internet
for chatting.

Output Devices

Output devices display the result of the input after it has been processed. Let’s learn about
diff erent output devices.

Monitor

Monitor, also known as visual display unit (VDU), is the most
important output device. The screen of a monitor is made up
of tiny dots called pixels, which are arranged in a rectangular
form. The resolution (sharpness of an image) of the monitor
depends upon these pixels. There are three types of monitors:
cathode ray tube (CRT) monitor, liquid crystal display (LCD)
monitor and light-emitting diode (LED) monitor.

Printer
A printer is an output device that allows us to print our work on paper. There are mainly three
types of printers on the basis of print method or print technology which are very popular
nowadays.

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