3. OUT PUT UNIT
The final part of a computer is the output unit.
Which presents the result machine operations in
printed or other visual form , or an tapes and
disks.
It is a device which receives results from CPU.
It is used to transfer information out of the
computing system.
5. HARD COPY
An output is said to be in its hardcopy from
when it is contained on some hard surface
like paper, glass and plastic.
In this form an output can be seen as well
as touched.
6. SOFT COPY
Another form of output that can be seen but
cannot be touched is its soft copy.
In this form of output exists till the computer is on
if the computer is switched off then the softcopy
of output disappears.
Softcopies of output are generated through
computer monitors, speakers and other output
devices.
8. PRINTER
It is an output device that character on paper and
provides a permanent visual record of data .
The result we get through printer is called print out
or hard copy .
Printer is invented by Chester Carlson in 1938.
9. IMPACT CHARACTER PRINTER
Prints on character at a time at speed ten
to five hundreds character per second an
thus, form the slowest class of printer.
11. IMPACT LINE PRINTER
Impact line printer is capable of
printing whole line at a time.
They can be categorized as
wheel printers, drum printers,
band printers, or chain printers.
13. WHEEL PRINTER
It can print up to 150 lines per minute.
It has a separate print wheel for each position in
the line.
Appropriate characters are adjusted by rotating
the wheel and then a hammer presses the ribbon,
paper and wheel to print those characters on the
paper.
15. DRUM PRINTER
It can prints 3000 lines per minute.
The characters are embossed on its
surface.
These characters are printed on the
paper when hammer strikes on the
paper and the rotating drum .
When an appropriate character comes
into position.
18. BAND PRINTER
It has a steel band divided into five sections of
forty eight characters each.
The printed output produced when the band
moves and appropriate characters comes into
position, is stuck out by its own hammer against
the band , paper and the ribbon .
It prints 3000 lines per minute.
20. CHAIN PRINTER
If works same as the band printer but
it has a linked chain composed of
character instead of a band .
It can print at the speed of up to 3000
lines per minute.
22. DOT MATRIX PRINTER
An arrangement of tiny hammers strikes to
produce the desired characters.
Each hammer prints a small dot on the
paper and hence the letters is produced
and thus it is called dot matrix printer.
24. INK JET PRINTER
Ink jet printer spraying electrically charged
particles , from selected nozzles to form an
image on paper.
There are quiet and fast but more
expensive than dot matrix printer.
26. PLOTTERS
A plotters generated hardcopies of drawing such as lines
,engineering maps, machines, building design, graphs etc in
very accurate manner.
Plotters may use colors or specific inks for their drawings.
A plotter is composed of a hard metallic strip on which
mechanical hand moves towards left and right.
33. PROJECTORS
Projectors are often used in meetings and
presentations to help an make sure every
thing.
It can display of a computer screen and
projects a large version of it onto a flat
surface.
34. MONITORS
It display / shows pictures .
It shows output.
It looks like television but it has a
differences like monitors don’t have tuner
to change channels.
35. LIQUID CRYSTAL DISPLAY
LCD are super thin display that are used in
laptops ,computer screens and flat panel
monitors.
The image of LCD screen is created by
sandwiching electrically reactive substance
between two electrodes.