A
peripheral device is generally defined as any auxiliary device such as a
computer mouse or keyboard that connects to and works with the computer in some
way. Other examples of peripherals are Image Scanners, Printers, Microphones, Loudspeakers,
Webcams, and Digital Cameras.
Types
of Peripheral Devices
1.
Input Devices
2.
Output Devices
3.
Storage Devices
1.
Input
Devices
Mouse
A mouse is a
small device that a computer user pushes across a desk surface in order to
point to a place on a display screen and to select one or more actions to take
from that position.
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.
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.
Keyboard
Keyboard is the most common and very popular input device which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.
The keys on the
keyboard are as follows:
Printer
A
printer is an external hardware output device responsible for taking electronic
data stored on a computer or computing device and generating a hard copy of
that data. Printers are one of the most commonly used peripherals on computers
and are commonly used to print text and photos. The picture to the right is an
example of a computer printer, the Lexmark Z605 Inkjet printer.
Types
of Printers
Since
the invention of the printing technology, a variety of technologies have been
employed in computer printers.
Broadly
printers are categorized as
1.Impact Printers
2.Non-Impact Printers
1.
Daisy
Wheel Printers
Daisy wheel printers print only
characters and symbols and cannot print graphics. They are generally slow with
a printing speed of about 10 to 75 characters per second. By 1980 daisy wheel
printers were the dominant printers for quality printing but since the prices
of laser and inkjet printers have declined and quality of dot matrix printers
has been improved, the daisy wheel printers are now obsolete.
2.
Dot
Matrix Printers
It is a popular
computer printer that prints text and graphics on the paper by using tiny dots
to form the desired shapes. It uses an array of metal pins known as print head
to strike an inked printer ribbon and produce dots on the paper. These
combinations of dots form the desired shape on the paper. Generally they print
with a speed of 50 to 500 characters per second as per the quality of the
printing is desired. The quality of print is determined by the number of pins
used (varying from 9 to 24).
3.
Inkjet
Printers
Inkjet printers are most
popular printers for home and small scale offices as they have a reasonable
cost and a good quality Inkjet printer of printing as well. A typical inkjet
printer can print with a resolution of more than 300 dpi and some good quality
inkjet printers are able to produce full colored hard copies at 600 dpi.
4.
Laser
Printers
Laser printers are the
most popular printers that are mainly used for large scale qualitative
printing. They are among the most popularly used fastest printers available in
the market. A laser printer uses a slight different approach for printing. It
does not use ink like inkjet printers, instead it uses a very fine powder known
as ‘Toner’. Components of a laser printer is shown in the following image:
