IGCSE ICT - Input and Output Devices - Output Devices and Their Uses - Ajiro Tech - Part 3

2.3 Output devices and their uses
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• Identify output devices and their uses, e.g. CRT monitor, TFT/LCD monitor, IPS/LCD
monitor, LED monitor, touch screen (as an output device), multimedia projector, laser
printer, inkjet printer, dot matrix printer, wide format printer, 3D printer, speakers,
motors, buzzers, heaters, lights/lamps
• Describe the advantages and disadvantages of any of the above devices
A J I R O N D I
Ajiro Tech – Best IGCSE ICT YouTube Channel
Chapter
2:
Input
and
output
devices

devices that usually show the result of computer processing in a format that can be understood by a human
(for example, on a monitor or printed on paper).
A J I R O N D I
Chapter
2:
Input
and
output
devices
2
Device Uses Advantages Disadvantages
Monitors (screens):
CRT monitors
❖ the least expensive type of
monitor.
❖ They come in various sizes and
make use of an electron gun
firing.
❖ The picture is made up of tiny
dots which are coloured red,
green or blue
❖ They are only used in
specialist areas, such as
computer-aided design
(CAD)
❖ They are used with light
pens to allow designs to be
created on screen.
❖ The screen can be clearly
seen at a wider range of
viewing angles than with
most LCD monitors.
❖ They allow the use of light
pens in, for example,
CAD/CAM applications
❖ They tend to be rather
heavy and present a weight
hazard if not supported
properly
❖ They run very hot and can
cause fires if left
unattended
❖ They consume considerably
more power than LCD
monitors.
Monitors (screens):
LED and LCD screens
❖ LED screen tends to be used
for large outdoor displays, due
to the brilliance of the colours
produced
❖ LCD screens are made up of
tiny liquid crystals. These tiny
crystals make up an array of
pixels which are affected by
changes in applied electric
fields
❖ Modern LCD screens are
backlit using light emitting
diode (LED) technology
❖ Very efficient, low power
consumption.
❖ Lightweight devices.
❖ Do not suffer from screen image
burn-in
❖ Do not suffer from a flickering
image, unlike CRT monitors.
❖ Very sharp image resolution
(allow a vast range of colours).
❖ Produce low electromagnetic
fields compared to CRT
monitors
❖ Used as the main output device
for most modern computers.
❖ Many LCD screens offer touch-
screen input.
❖ Mobile phones, tablets, laptops
and portable video games all
use LCD screens
❖ Colour and contrast from
various viewing angles can be
inconsistent.
❖ Motion blur is a common
issue.
❖ Lower contrast than CRT
monitors, because it is harder
to produce a deep, rich level
of black.
❖ The LCD panel may not be
uniformly illuminated by the
back light, resulting in uneven
intensity and shading over the
screen.

A J I R O N D I
Chapter
2:
Input
and
output
devices
3
Touch screen
Touch screens function as both
input and output devices, allowing
users to interact by touching
displayed options, such as selecting
food at a fast-food outlet, which
then generates new options
❖ Smartphones and tablets
(allowing interaction with
apps).
❖ ATMs at banks (where
screen options displayed
depend on previous input
❖ response).
❖ Ticket collection machines
at theatres, cinemas and
railway stations
❖ Faster entry of options than
using a keyboard or mouse.
❖ Very easy method for
choosing options.
❖ User-friendly method – no
training necessary in its use.
❖ Option to expand the size of
the display if necessary
❖ Limited number of options
available.
❖ The screen can get very dirty
with constant touching
(reducing its responsiveness
and making it more difficult to
read in strong sunlight)
Multimedia projectors
Multimedia projectors receive
signals that can be either analogue
or digital (although most modern
projectors only work with digital
inputs). The signal source is usually
from a computer, television or DVD
player. The image from the source
is magnified and projected onto a
large screen.
❖ Enables many people to see a
presentation rather than
crowding around a small
computer screen.
❖ Avoids the need for several
networked computers (for
example, when looking
❖ at a video clip on an internet
site, everybody can see the
video on the large screen rather
than logging on to a number of
computers).
❖ Training presentations (to allow
the whole audience to see the
images from a computer).
❖ Advertising presentations (large
images showing product
features, for example a new car;
can be shown at exhibitions,
shopping malls).
❖ Home cinema systems
(projecting the images from a
DVD or television).
❖ Images can sometimes be
fuzzy.
❖ Expensive to buy.
❖ Setting up projectors can be a
little difficult.

A J I R O N D I
Chapter
2:
Input
and
output
devices
4
Printers: Laser printers
produce very high-quality hard
copy output. The print rate per
page is very quick if a large number
of pages are being printed. They
rely on large buffer memories
where the data for the whole
document is stored before pages
can be printed out.
❖ They are used where low
noise is required (for
example, in an office).
❖ If fast, high-quality, high-
volume printing is required
then laser printers are
❖ the best option.
❖ Printing is fast
❖ They can handle very large
print jobs.
❖ The quality is consistently high.
❖ Toner cartridges last for a long
time (and the printers can
sometimes be a cost-effective
option, particularly if colour
outputs are not required).
❖ Only really fast if several
copies are being made.
❖ Colour laser printers tend to
be expensive to run
❖ They produce ozone and
volatile organic compounds
because of their method of
printing and type of toner/ink
used (these have been linked
to health hazards in the office)
Printers: Inkjet printers
❖ used to produce good-quality
hard copies.
❖ do not have large buffer
memories, therefore printing is
done a bit at a time.
❖ the whole print job cannot be
stored in the buffer, and it has
to wait for the computer to
send more data
❖ High-quality output.
❖ Cheaper to buy than laser
printers.
❖ Very lightweight and have a
small physical footprint.
❖ Do not produce ozone and
volatile organic compounds,
unlike laser printers
❖ Used where low-output
volumes are required (high-
volume jobs are difficult to do
because the ink cartridges tend
to be used up very quickly).
❖ If high-quality printing is
required for single pages (or
only a small print job) then
these printers are ideal; for
example, they are very good at
producing photo-quality
printouts.
❖ 3D inkjet printers are now being
used in industry to produce
prototypes
❖ Slow output if several copies
are needed (little buffer
capacity to store the pages).
❖ Cannot do large print jobs (ink
cartridges run out too
quickly).
❖ Printing can ‘smudge’ if the
user is not careful.
❖ Can be expensive if used a lot
(original ink cartridges are
expensive to buy).

A J I R O N D I
Chapter
2:
Input
and
output
devices
5
Printers: Dot matrix printers
❖ type of impact printer where a
print head (matrix of pins)
presses against an inked ribbon.
❖ tend to be slow, noisy and the
output is not that good
compared
❖ They are still useful, however,
where multipart stationery
(carbon copies) are used.
❖ They can be used in noisy or
dirty environments (for
example,
❖ They are used in
applications where multi-
part stationery is of value
❖ they are an impact printer is
of value.
❖ » Still widely used in till
receipts.
❖ They can be used in
environments which would be a
problem for laser or inkjet
printers
❖ Carbon copies or multi-part
outputs can be produced.
❖ Very cheap to run and
maintain.
❖ Easy to use if continuous
stationery is required
❖ Very noisy – not good in an
office environment.
❖ Actually cost more than an
inkjet printer to buy initially.
❖ Very slow, poor-quality
printing.
(Graph) plotters
❖ Although they print on paper,
they work very differently to
printers.
❖ Instead of toner or ink
cartridges, plotters use a pen,
pencil or marker pen to draw
multiple continuous lines, rather
than a series of dots like a
printer
❖ Very high-quality output.
❖ Able to produce large,
monochrome and colour
drawings to a high accuracy.
❖ Able to print on a variety of
materials (for example,
aluminium, cardboard, plastic,
steel and wood) as well as
paper.
❖ Producing architectural
drawings.
❖ Producing engineering
drawings.
❖ Drawing animation characters
(cartoon characters).
❖ Very slow at printing.
❖ Expensive equipment (and
software) to purchase initially;
although running costs are
low once purchased.
❖ Have a very large physical
footprint compared to a
printer.

A J I R O N D I
Chapter
2:
Input
and
output
devices
6
3D printers
❖ primarily used in computer-
aided design (CAD) applications
❖ primarily based on inkjet and
laser printer technology and can
produce solid objects that
actually work.
❖ The solid object is built up layer
by layer using materials such as
powdered resin, powdered
metal, paper or ceramic.
❖ Prosthetic limbs can be made
to fit exactly on the injured
body part.
❖ Making items to allow
precision reconstructive
surgery
❖ In aerospace, manufacturers
are looking at making wings
and other aeroplane parts
using 3D technology;
❖ 3D printers allow users to
create customized products
from designs.(Manufacturing)
❖ 3D printers enable rapid
prototyping, converting designs
into working prototypes quickly
and efficiently.
❖ Despite high costs, 3D printing
is cheaper than traditional
manufacturing and beneficial
for any production
❖ The biggest drawback of 3D
printers is the potential for
creating counterfeit or
copyright-infringing items.
❖ New technologies, like 3D
printers, can be misused to
manufacture dangerous or
illegal items.
❖ 3D printing may cause job
losses in manufacturing,
though it could lower costs for
companies.
Speakers
❖ produce sound
❖ When connected to a computer
system, digitised sound stored
on a file needs to be converted
into sound
❖ Sounds amplified through
speakers can be much louder
than the original sound
❖ Everyone in a conference, for
example, can hear the output
from a computer.
❖ It can create a good atmosphere
when making a presentation.
❖ They can help visually impaired
people as discussed.
❖ Very simple technology.
❖ Used in all phones and built in
to most computers.
❖ Outputs sound from multimedia
presentations.
❖ Helps visually impaired people
(together with speech
generation software) through
reading aloud text on the
screen.
❖ Plays downloaded sound files.
❖ Speaker output can be
disturbing to others in, for
example, an office
environment.
❖ To get high-quality sound, the
required speakers can be
quite expensive.
❖ Speakers can take up a lot of
desk space.

A J I R O N D I
Chapter
2:
Input
and
output
devices
7
Actuators
❖ When a computer is used to
control devices, such as a
conveyer belt or a valve, it is
usually necessary to use an
actuator
❖ mechanical or
electromechanical device such as
a relay, solenoid or motor
❖ They are used to control
motors, pumps, switches,
buzzers and so on.
❖ They allow a computer to
control physical devices that
normally require analogue
inputs.
❖ They allow remote operation of
many devices (for example,
pumps in a nuclear
❖ reactor where remote
operation is a big safety factor).
❖ They are relatively inexpensive
devices.
❖ They are an additional device
in the system that could go
wrong.
❖ Because they are usually
analogue devices, computer
signals need to converted
using a DAC to enable
computer control.

IGCSE ICT - Input and Output Devices - Output Devices and Their Uses - Ajiro Tech - Part 3

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IGCSE ICT - Input and Output Devices - Output Devices and Their Uses - Ajiro Tech - Part 3