Input Devices of Computer

1. INPUT DEVICES OF COMPUTER
BY
Dr.M.BALASUBRAMANIAM

2. INTRODUCTION
 The term computer is
derived from the latin word
computare which means To
compute or To calculate. So it
is considered to be a device.

3. DEFINITIONS
 Computer is an automatic
electronic apparatus for making
calculation or controlling operation,that
are expressible in numerical or logical
terms
 The computer is an
electronic device which converts row
data into valid or meaningful information

4. COMPONENTS OF COMPUTER
Hardware Software
CPU pheriperial
Input devices Output devices
System Software Application
Software

5. COMPUTER PHERIPERALS
 A computer peripherals
consists of mainly two types
namely
 1.INPUT DEVICE
 2.OUTPUT DEVICES

6. INPUT DEVICES
The input devices is used to send
information or instructions or
commands to the computer. The data
received from the input units
immediately stored in main memory
and then processed.

7. All the input devices perform the
following Functions:
 Accept data and instructions from the
outside world.
 Convert it to a form that the computer
can understood.
 Supply the converted data to the
computer system for further
processing.

8. Types of input devices
 Keyboard
 Mouse
 Mouse pad
 Joystick
 Digitizing tablets
 Scanners
 Digital camera
 MICR
 OMR
 Barcode reader
 Speech input
devices
 Touch screen
 Touch pad
 Light pen

9. KEYBOARD
Keyboard is a
device used for issuing
directions to the
Computer and it is
used to information or
data and commands to
the computer.

10. TYPES OF KEYBOARD
There are three
different pc
Keyboards:
 1.Original
keyboard with
84 keys
 AT keyboard with
101 keys.
 Enhanced
keyboard with
101 keys
They differ in the
placement of function
keys,control keys,
Retrun key and shift
key.
KeyBoard are often
classified as Follows.

11. 1.Alphanumeric keys-letters and
numbers
2. Punctuation key-Period, semicolon
and so on.
3.Special keys- function keys, control
keys,arrow and caps lock keys.

12. MOUSE
 A mouse is a
hand- Held pointing
device that allows us to
controls the Movement of
the cursor or the pointer.
 Mouse is imp. For
graphical programs that
allows you to draw
pictures.

13. TYPE OF MOUSE
 1. Mechanical mouse
 2. Opto – mechanical mouse
 3. Optical mouse
 4. Cordless mouse

14. MOUSE PAD
 Mouse pad is a pad over which a
mouse can move.
 It provide more traction than
smooth surface such as glass and
wood.
 They make it easier to move a
mouse accurately.

15. TRACK BALL
o It is a pointing
device which has a
mouse lying on its
back.
o It can also placed
on any type of
surface.
o It is popular
pointing device.

16. JOYSTICK
 It is a lever that
moves in all
directions.
 It has two buttons
called triggers.
 It is mostly used for
computer games.

17. DIGITIZING TABLET
It enables to enter
drawings and
sketches into a
computer.
The tablet contains
electronic grid that
translates the
movement.

18. SCANNER
It can read text or
illustrations.
Translate the
information into
the computer.

19. TYPES OF SCANNER
1. Flat bed scanner.
2. Hand held scanner.
3. Sheet fed scanner.

20. DIGITAL CAMERA
It takes a still
photograph.
It store and send
it as input into a
computer.
Images are stored
as digital files.

21. MAGNETIC INK CHARACTER
RECOGNITION
It recognize
character printer
sing magnetic ink.
It is a direct entry
method used in
banks.

22. OPTICAL MARK RECOGNITION
OMR is also called
mark sensing.
It device senses
the presence or
absence of mark.
It is used in
aptitude test.

23. BARCODE READER
It is photoelectric
scanners.
It reads the
vertical zebra
striped marks.
It is familiar in
supermarkets,shop
s.

24. TOUCH SCREEN
It is a type of
display screen.
It has touch
sensitive
transparent panel
covering the
screen.
By using the
fingers directly
point the object on
the screen.

25. TOUCH PAD
A small touch
sensitive pad use
as a pointing
device.
It is used in
portable
computers.

26. LIGHT PEN
It is directly used
to move the
pointer and select
objects on screen.
It utilizes a light
sensitive detector
to select the
objects.