What is
printer?
A printer is an
electronicmechanical device which converts text and graphical documents for an
electronic from to a physical form. The quality of printers is indefined by
features like colour quality, speed of printing, resolution, etc. Printers are
external peripheral devices which are connected with computers or laptop
through a cable or wirelessly to receive Input and print them on paper.
Printing
Technology
There are a variety of technologies that are used in computer
printers ever since the invention of printing technology. Now-a-days, printers
come with multipurpose functions which include scanner, photocopier , fax, etc.
This helps to serve different needs based on the form the different types of
technologies.
Types of printers
Based on the
technology used, printers are broadly Categoriesed as :-
Printer :-
(I) Impact printer
(a) Character printer
(i) Dot Matrix (
b) Line printer
(II) Non-
impact printer
(a)
Character printer
(i) Ink-jet printer
(b) Page printer
(i) Laser printer
Impact
printer :- Where
there is a physical contact between the print head, ribbon or cartridge and
paper ( media).
Non- impact
printer :- Where
there is no physical contact between the print head, cartridge and paper(
media).
Impact printer :-
Dot Matrix
Printer
Dot Matrix printer is an example of impact printer which
print text on paper by using ting dots to form desired character.
It uses an array of
metal pins known as print head to strike an inked printer ribbon and produce
dots on paper.
It prints with a speed of 100 to 600 character per second
(cps).
The number of pins used in print heads varies from 9 to 24 .
It can print only in black and white.
Impact
printer :
line printer -- It is a type of impact printer.
Where enormous amount of material is to be printed, users
need line printers.
Line printer, or line-at-a-time printers , used a special
mechanism that can print a whole line at once.
They can print the range of 1,200 to 6,000 lines per
minute(Ipm).Drum, Chain and band printers are line-at-a-time printers.
Non-impact :
Inkjet printers
Inkjet printers work in the same fashion as dot-matrix
printer, however here, the dots are formed by tiny droplets of ink.
Inkjet printers from character on paper by spraying ink from
tiny nozzels through an electrical field that arranges the charged particles
into characters at the rate of approximately 250 characters per second (cps).
The ink is absorbed into the paper and dries instantly. Inkjet
printers can print in colours too. Ink
cartridge per page costs is much higher than that of a Laser printer.
Non-impact : Laser printer
It is type of non impact printer.
This printer works like a photocopy machine.
Using pattern of small dots, a laser beam transfers
information from the computer to a positively charged drum.
The toner ( ink powder) detaches from all those
areas of the drum that becomes neutralized.
As the paper rolls by the drum, the toner (ink
powder) is transferred to the paper, printing the letters or other graphics on
the paper.
A hot roller bonds the toner to the paper. -- It
prints the whole page at a time.
Depending on
the model, it either can print in colour or black and white
A laser printer costs more than an inkjet printer
but the running cost ( toner cost per page ) is much lower.
