BTEC ICT Level 3
Unit 1
Task 3
Adrian Koopmann Rocha
Peripherals
A monitor is a piece of hardware used for observing what the user is
doing and receives its information from the actual computer
(motherboard). A monitor is an out device due to it outputting
information out to the user, it displays visual information so in forms
of images and sounds. A TFT monitor is short for Thin Film
Transistor, a type of LCD (Liquid-Crystal-Display) flat-panel display
screen, in which each pixel is controlled by from one to four
transistors. The TFT technology provides the best resolution of all the
flat-panel techniques, but it is also the most expensive. TFT screens
are sometimes called Active-Matrix LCDs. CRT is the abbreviation
of Cathode-Ray Tube, the technology used in most televisions and
computer display screens. A CRT works by moving an electron beam
back and forth across the back of the screen. Each time the beam
makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby
illuminating the active portions of the screen. By drawing many such lines from the top to the bottom
of the screen, it creates an entire screen full of images. A VGA (Video Graphics Array) connector is a
three-row 15-pin DE-15 connector which found on many video cards, computer monitors, and high
definition television sets. The VGA interface is not engineered to be hot pluggable (so that the user
can connect or disconnect the output device while the host is running), although in practice this can be
done and usually does not cause damage to the hardware or other problems. HDMI (High-Definition
Multimedia Interface) provides an interface between any audio/video source, such as a set-top box,
DVD player, or A/V receiver and an audio and/or video monitor, such as a digital television (DTV),
over a single cable. By delivering crystal-clear, all-digital audio and video via a single cable, HDMI
dramatically simplifies cabling and helps provide consumers with the highest-quality home theatre
experience.
The difference between TFT and CRT monitors are that CRT monitors are the old traditional version
monitors that look like TVs while TFT are flat screens. CRT monitors also provide a higher level of
colour response than TFT screens which have poor colour resolution. In the last 11 years (Since 2003
when the TFT sold more than the CRT) the TFT monitor has been a lot more popular, this could be
because of aesthetics but many people would argue that it is for its technological advantages the TFT
has. The CRT is now considered the older model of a computer mainly because it was created first but
it is also due to its slower speed, making it the less desirable option.
A printer is a machine for printing text or pictures, especially one linked to a computer. There are two
types of printers:
-Inkjet: A type of printer that works by spraying ionized ink at a sheet of paper. Magnetized plates in
the ink's path direct the ink onto the paper in the desired shapes. Ink-jet printers are capable of
producing high quality print approaching that produced by laser printers.
-LaserJet: A type of printer that utilizes a laser beam to produce an image on a drum. The light of the
laser alters the electrical charge on the drum wherever it hits. The drum is then rolled through a
reservoir of toner, which is picked up by the charged portions of the drum. Finally, the toner is
transferred to the paper through a combination of heat and pressure. This is also the way copy
machines work.
In general, the price of ink-jet printers is higher than that of
laser printers and they are also considerably slower. One
drawback of ink-jet printers is that they require a special type
of ink that is apt to smudge on inexpensive copier paper. Inkjet printers require smaller mechanical parts than laser printers;
BTEC ICT Level 3
Unit 1
Task 3
Adrian Koopmann Rocha
they are especially popular as portable printers. In addition, colour ink-jet printers provide an
inexpensive way to print full-colour documents. Contrastingly, we have these different types of
printers because of technical advancements in printers. The ink jet printer came out first and was
popular to a lot of people at the time because it was a new type of hardware. Then the laser jet printer
came out and seemed to take all the popularity away from the ink jet, this is due to the fact that the
laser jet was cheaper and produced better quality print outs. Also the ink jets need a constant supply of
ink, which is costly and isn’t always readily available, making laser jet printers the obvious option to
buy.
A Plotter is a piece of equipment that marks out the points on a chart. In the past, Plotters were used
in applications such as CAD, though they have generally been replaced with wide-format
conventional printers. A Plotter gives a hard copy of the output. It draws pictures on paper using a
pen. Plotters are used to print designs of ships and machines, plans for buildings and so on. Who
would need this in life? Anyone who needs to make professional poster and billboard-making
businesses to produce weather-resistant signs, posters, and billboards will need plotters because they
need to know where to cut and make insertions, this is critical to the creation of their work. Plotters
can also a computer printer and printing vector graphics.
A camera is by Google’s definition:
“A camera is a device for recording visual images in the form of photographs, movie film or video
signals.”
Here are the different types of cameras:
- Single use Cameras
- Compact Lens-Shutter
- Bridge Cameras
- Rangefinders
- Twin Lens Reflex
- SLR (Single Len Reflex)
Single Use Cameras: These cameras are the simplest cameras because they
contain a roll of colour film encased in a recyclable cardboard. They have a single
shutter speed and a fixed-focused lens. These cameras can be bought with a
variety of features, including a built-in-flash and water resistance. The whole
camera has to be taken to the photo finisher so that the film can be processed.
These cameras can be recycled and cost around £10; they shouldn’t be used for
serious photography because they don’t have the range or resolution. They’re
convenient for holidays, festivals or somewhere you may not want to take your
expensive camera.
Compact Lens: Shutter Bridge Cameras: Compact Lens-Shutter Cameras come
in three different varieties: single focal length, dual focal length and zoom.
Some have fixed focus, meaning that the focus is fixed at a point that produced
sharp images starting from 5ft away and going on. Other cameras offer infrared
auto focusing. Some models offer features like red-eye reduction flash and
several automatic shooting models. Some professional photographers usually
prefer to have more control over the pictures they take.
Bridge Cameras: Bridge Cameras are the intermediate cameras. They bridge gaps
between ‘point and shoot’ cameras and the more serious or complex models,
hence the name. They have different lenses and may offer red-eye reducing flash.
There is only a limited range of lens focal length that can be used with these
cameras.
BTEC ICT Level 3
Unit 1
Task 3
Adrian Koopmann Rocha
Rangefinders: These are compact, lightweight cameras that are often used for serious
photography. They offer interchangeable lenses and allow photographers to control
shutter speed, lens aperture, focusing and exposure. Some disadvantages are that it is
limited in focal length (from 21mm-135mm) and they tend to be more expensive than the
ones above.
Twin Lens Reflex: The twin lens reflex is a medium-format camera (one that uses a film
larger than 35mm). It is fitted with two lenses with both have the same focal length, one
mounted atop the other. The lower (taking) lens focuses its image directly on the film, while
the image produced by the upper viewing lens is reflected through 90 degrees by a mirror,
then bought to focus on a horizontal ground-glass focusing screen. The light paths to the
focusing screen and the film plane are equal, so that if the photographer brings the scene on
the focusing screens to sharp focus.
SLR: The SLR requires one lens for both viewing and creating the photo. This is a
sophisticated camera that offers full manual control of exposure and focus. SLR
cameras will accept interchangeable lenses; add on flashes, motor drives and other
accessories. There are also Auto Focus SLR’s. There can be set in a number of
different modes to ease taking. These cameras are usually used by professional
photographers.
Scanners are versatile; many scan slides and negatives as well as paper, and almost all come with
software for editing images. Plus many come with an optical character recognition program (OCR) for
converting hard-copy text into editable documents. These pieces of hardware are able to scan material
from both thick and thin objects; these can be ranging from single sheets of paper to selections from
thicker books and magazines. Simply place the object you would like to scan on the glass plate and
the scanning head capture the image. There are different scanners for different things:
- A flatbed scanner is the one I explained above.
- A duplex scanner simultaneously scans the front and back of a document
- Automatic Feeder scanners (ADF scanners) automatically feed your documents for
continuous scanning. This is ideal for scanning a high volume of loose pages as quickly as
possible.
Coaxial cables are a type of cable that has an inner conductor surrounded by a
tubular insulating layer; this is then surrounded by a tubular conducting shield
which is useful because it acts as protection for the wires. Many coaxial cables
also have an insulating outer sheath or jacket. Coaxial cables are used as
a transmission line for radio frequency signals which basically means anything
electronic which needs to be transmitted. Its applications include feed
lines connecting radio transmitters and receivers with their antennas, computer
network (Internet) connections, and distributing cable television signals. So
there is a high chance this sort of cable could be what makes your TV, phone and internet work. One
advantage of coaxial over other types of radio transmission line is that in an ideal coaxial cable
the electromagnetic field carrying the signal exists only in the space between the inner and
outer conductors. These cables are relatively cheap; they sell from £2.99 to £24.99 depending on
length and age.
Optical fibre cables are a cable containing one or more optical fibres. It's a
technology which uses glass (or plastic) threads (fibres) to transmit data. A
fibre optic cable consists of a bundle of glass threads, each of which is capable
of transmitting messages modulated onto light waves. The optical fibre
elements are typically individually coated with plastic layers and contained in
BTEC ICT Level 3
Unit 1
Task 3
Adrian Koopmann Rocha
a protective tube suitable for the environment where the cable will be deployed. Similarly to the
coaxial cables, these cables are readily available and are cheap on the internet, going from £0.99 to
£4.99 depending on size/length and age. Different types of cable are used for different applications,
for example long distance telecommunication, or providing a high-speed data connection between
different parts of a building.
Twisted pair cables are a type of cable that consists of two independently insulated wires twisted
around one another. The use of two wires twisted together helps to reduce crosstalk and
electromagnetic induction. These are usually use by older telephone networks and are the cheapest
LAN cable. The advantages of this cable are that it is cheaper and easier to splice, less susceptible to
electrical interference caused by other equipment and is less likely to cause interference to them.
Equally, the STP (Shielded Twisted Pair) wire is physically larger which means it is expensive and it
is more difficult to connect to a terminating block.