Unit II: Input Devices
1. Definition of Input Devices
2. its type (Mouse, Keyboard, Microphone, Scanner, TouchPanel, MICR, OBR and
3. Uses of input devices.
Content of this unit
What is Input Device?
An input device is any hardware device that sends
data or instruction to a computer, allowing you to
interact with and control it.
Keyboard and mouse are primary input devices of
There are many types of input devices like:
Microphone, Scanner, webcam, bar-code Reader,
TouchPanel, MICR, OBR(Optical Braille
Recognition)and OMR (Optical Mark Recognition)
Keyboard is an input device consisting of a set of typewriter like keys
that enables you to enter data into a computer.
Computer keyboards are similar to electric typewriter keyboard but
contains additional keys .
Different types of keys are:
Alphanumeric Keys: alphabet and numbers
Punctuation Keys: Comma, Period, Semicolon and so on.
Special Keys: Function, Command, arrow, Caps lock etc.
The standard layout of keyboard is QWERTY keyboard.
It was designed in 1800 for mechanical typewriter to write slowly to
avoid jam while typing.
Another keyboard design for fast typing is Dvorak Design
IBM Keyboard contains additional page up, page down, home, end,
Insert, pause, numlock, scroll, break, etc
Apple computer have several keyboards called ADB keyboards
Mouse is a device that controls the movement of the cursor or pointer on
A mouse is a small device that can be roll along the hard flat surface.
Mouse / Mice contains at least one button and sometimes three buttons
which have different functions.
Invented by Douglas Engelbart of Stanford Research Center in 1963, and
pioneered by Xerox in 1970
Mouse is a breakthrough technology to use as main input device in GUI
Types of Mouse/Mice:
Mechanical: Used Metal or rubber ball as it can know the direction of device
with the rolling.
Opto-mechanical: Used optical sensor but still is mechanical mouse.
Optical: Uses laser to detect the mouse’s movement. It is more quick than
Mouse or mice are connected to PC with either Serial mice Connect which
is PS/2 port or Bus mice through interface card or Cordless which is not
A Microphone is an input device that was developed by Emile Berliner
It is used to convert sound waves into electric waves or input the audio
It captures audio by converting sound waves into an electrical signal,
which may be a digital or analog signal.
This process can be implemented by a computer or other digital audio
Regularly, microphones are designed on the basis of directionality,
besides the type of device.
Such as, Omnidirectional microphones are capable of picking up all
sounds in an area, but it is unable to dfocus on a particular subject with
What is the use of a microphone on the computer?
It is used for voice recording.
It offers users the option of voice recognition.
It allows users to record sound of musical instruments.
It enables users to online chatting.
It allows us for VoIP (Voice over internet protocol).
It is also used for Computer gaming.
Furthermore, it can record voice for singing, podcasts, and dictation.
Scanner is an input device that reads text or image that translated the
information into a form that the computer uses.
Scanner works by digitizing an image dividing into a grid of boxes and
representing each box whether with zero or one.
The resulting matrix of bits, called a bit map can then be stored in a file,
displayed on a screen and manipulated by programs.
Optical scanners do not distinguish text from illustrations.
For reading text type scanning require OCR (Optical Character
Recognition) system to translate the image into ASCII characters
Different Types of Scanner:
Flatbed Scanner: It has a glass pane and a moving optical CIS or CCD array.
Handheld Scanner: It is a small manual scanning device which is held by hand
and is rolled over a flat image that is to be scanned.
Sheetfed Scanner: In this scanner, the document is inserted into the slot
provided in the scanner.
Drum Scanner: Drum scanner has a photomultiplier tube (PMT) to scan
Photo Scanner: It is designed to scan photographs.
Touch panel or screen is a type of display screen that
has a touch sensitive transparent panel covering the
Instead of using a pointing device such as a mouse or
light pen, you can use your finger to point directly to
objects on the screen.
Although screens provide a natural interface for
These types of devices like smartphone, tablet, touch
monitors that uses touch of a figure as input data.
But due to the big size of the finger touch some time
its is not ideal for input.
For that a touch pen can be useful as the touch point
of pen will be much smaller than that of a figure which
can be useful for some precise work like graphics
MICR (magnetic ink character recognition) is a technology
invented in the 1950s that's used to verify the legitimacy or
originality of checks and other paper documents.
It allows the computer to recognize characters printed using
It is use in bank.
In the bank, cheques that are have some number which is printed
on the bottom are made with special type of magnetic ink and
these devices reads those characters.
Some other related technology will be debit / credit card black
magnetic strip which is read in ATM machines some information
about user in a bank.
Another example can be ID card that which use such technology
to verify the user to enter some place or room.
Optical Bar Code Reader (OBR) which is used for reading bar-
It scans a set of vertical bars of different width for specific data
and is used to read tags.
Bar code reading is done by a light pen or scanner connected to
OMR is gathering information from human beings by recognizing
marks on a document.
OMR is accomplished using a hardware device (scanner) that detects
a reflection or limited light transmittance on or through a piece of
OMR allows for the processing of hundreds or thousands of
documents per hour.
For example, students may recall taking tests or surveys where they
filled in bubbles on paper (shown right) with a pencil.