Most Important Pointing Devices:
1. Mouse
2. Trackball
3. Pointing Stick
4. Joystick
5. Touch Pad
6. Touch Screen
7. Light Pen
8. Digitizer/Graphic Tablet
Mouse
Mouse is the most commonly used pointing input
devise. It is used to control the cursor or pointer on
the screen and to give commands to the computer.
The mouse is attached with the computer by a cable
or wireless connection.
The top of mouse contains one wheel and 2 or 3
buttons. These buttons can be clicked or double
clicked to perform different tasks.
Types of Mouse
There are Two most popular types of mouse are as
follows:
(i) Mechanical Mouse: It has a small ball at the
bottom. The ball rotates as the mouse is rolled over a
flat surface. Usually, a rectangular rubber pad
(known as mouse pad) is used as flat surface. As the
mouse is rolled over the flat surface, the pointer
moves in the same direction on the screen.
(ii) Optical Mouse: It has no ball at the bottom. It
uses the laser technology to detect the mouse
movement. Nowadays, it is commonly used in
personal computers (PCs).
Trackball
It performs functions like a mouse but it is a stationary
device. It has moveable ball on its top. The ball is rotated
or rolled with fingers or palm to move the pointer on the
screen. Like mouse, a trackball also has buttons used to
send the commands to computer.
The trackball is usually available in laptop computer.
It is fixed on its keyboard. It is also available as
separate input device.
Touch Pad/Track Pad
Touch Pad is a pressure-sensitive pointing device. It is
also stationary device like trackball but it has no
moving parts. It is a small, flat surface (or sensitive
pad) over which a user slides fingertip to move the
pointer on the screen.
Pointing Stick
A pointing stick is a pressure-sensitive pointing device.
It looks like a pencil eraser. It exists between keys of
keyboard. It is used to control the movement of a
pointer on the screen. The pointer in the screen
moves in the direction in which the pointing stick is
pushed. Pointing stick input device is normally used
with laptop computers.
Joystick
It consists of a vertical handle or hand-held stick. The
stick is mounted on a base. The hand-held stick is
used to control the movement of pointer on the
screen. The button of the joystick is pressed to
activate certain event or action. Joystick is basically
used to play video games. It is also used in some
computer-aided design (CAD) system.
Touch Screen
A touch screen is a special display screen. Input is
given to the computer directly by touching the
screen with user fingertip. Most touch screen
computers use sensors in the computer's screen
to detect the touch of a finger. Touch screen is
often used in ATM. Touch screen systems are also
used in restaurants, supermarkets, departmental
stores etc.
Light Pen
The light pen is a hand-held pointing input device. It is a light-sensitive input device. The tip of pen contains a light-sensitive element. This device also contains a button.
Input is given to the computer directly by touching the screen with pen. When the pen is touched with the screen, it detects or senses a position on display screen. The user points the object to be selected on the display screen and then presses a button on the light pen.
Light Pen device is usually used by engineers and graphic designers.
Digitizer or Graphics
Tablet
Digitizer is used for drawing new images or tracing old
images. it enables a user to hand-draw images,
animations, graphics, maps and engineering drawings.
These tablets may also be used to capture data or
handwritten signatures. It consists of a flat,
rectangular board (or pad) and an input device stylus
or puck. Each location on the rectangular board points
to corresponding position on the computer screen.
Stylus looks like a pen. It is used for drawing images on
a specially designed graphics screen or digitizer. Puck
looks like a mouse. Puck is also called cursor. For
tracing, the puck is preferred because its crosshairs.
