Mouse
Mouse
is most popular Pointing device. It is a very famous cursor-control device. It
is a small palm size box with a round ball at its base which senses the
movement of mouse and sends corresponding signals to CPU on pressing the
buttons.
Generally, it has two buttons called
left and right button and scroll bar is present at the mid. Mouse can be used
to control the position of cursor on screen, but it cannot be used to enter
text into the computer.
Advantages
CEasy
to use
CNot
very expensive
CMoves
the cursor faster than the arrow keys of keyboard.
Joystick
Joystick
is also a pointing device, which is used to move cursor position on a monitor
screen. It is a stick having a spherical ball at its both lower and upper ends.
The lower spherical ball moves in a socket. The joystick can be moved in all
four directions.
The
function of joystick is similar to that of a mouse. It is mainly used in
Computer Aided Designing (CAD) and playing computer games.
Light
Pen
Light
pen is a pointing device, which is similar to a pen. It is used to select a
displayed menu item or draw pictures on the monitor screen. It consists of a
photocell and an optical system placed in a small tube.
When
light pen's tip is moved over the monitor screen and pen button is pressed, its
photocell sensing element detects the screen location and sends the
corresponding signal to the CPU.
Track
Ball
Track
ball is an input device that is mostly used in notebook or laptop computer,
instead of a mouse. This is a ball, which is half inserted and by moving
fingers on ball, pointer can be moved.
Since
the whole device is not moved, a track ball requires less space than a mouse. A
track ball comes in various shapes like a ball, a button and a square.
Scanner
Scanner
is an input device, which works more like a photocopy machine. It is used when
some information is available on a paper and it is to be transferred to the
hard disc of the computer for further manipulation.
Scanner
captures images from the source which are then converted into the digital form
that can be stored on the disc. These images can be edited before they are
printed.
Digitizer
Digitizer
is an input device, which converts analog information into a digital form.
Digitizer can convert a signal from the television camera into a series of
numbers that could be stored in a computer. They can be used by the computer to
create a picture of whatever the camera had been pointed at.
Digitizer
is also known as Tablet or Graphics Tablet because it converts graphics and
pictorial data into binary inputs. A graphic tablet as digitizer is used for
doing fine works of drawing and images manipulation applications
Microphone
Microphone
is an input device to input sound that is then stored in digital form. The
microphone is used for various applications like adding sound to a multimedia
presentation or for mixing music.
Magnetic
Ink Card Reader (MICR)
MICR input
device is generally used in banks because of a large number of cheques to be
processed every day. The bank's code number and cheque number are printed on
the cheques with a special type of ink that contains particles of magnetic
material that are machine readable.
This reading
process is called Magnetic Ink Character Recognition (MICR). The main advantage
of MICR is that it is fast and less error prone.
Optical
Character Reader (OCR)
OCR is an input device used to read a
printed text. OCR scans text optically character by character, converts them
into a machine readable code and stores the text on the system memory.
Bar
Code Readers
Bar Code
Reader is a device used for reading bar coded data (data in form of light and
dark lines). Bar coded data is generally used in labelling goods, numbering the
books, etc. It may be a hand-held scanner or may be embedded in a stationary
scanner.
Bar Code
Reader scans a bar code image, converts it into an alphanumeric value, which is
then fed to the computer to which bar code reader is connected.
Optical
Mark Reader (OMR)
OMR is a special type of optical
scanner used to recognize the type of mark made by pen or pencil. It is used
where one out of a few alternatives is to be selected and marked. It is
specially used for checking the answer sheets of examinations having multiple
choice questions.
