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Flashcards in Output devices Deck (22)
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1
Q

Define

output device

A

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) which converts the electronically generated information into human-readable form

Taken from Wikipedia LAWL

2
Q

How does a inkjet printer work?

A
  • Uses a printhead to propel droplets of ink from fine nozzles onto paper
  • Printhead passes left and right across paper while roller feeds paper forwards
3
Q

List some advantages and disadvantages of inkjet printers

A

Advantages:

  • Good colour production (good for printing pictures)
  • Low purchase cost

Disadvantages:

  • Ink is expensive
  • Water-soluble ink smudged when damp
  • Slow output rate
4
Q

How does a laser printer work?

A
  • Uses a laser scanning a drum to print with powdered ink, called toner
  • Printer paces an even, negatively static charge on a photoconductive drum
  • Laser beam scanned on the rotating drum causes negative charge to leak away
  • Drum revolves past negatively charged toner supply which is attracted to the regions on the drum where no charge remains
5
Q

List some advantages and disadvantages of laser printers

A

Advantages:

  • High resolution and rate of output - useful when printing multiple copies of one sheet as the same pattern of negative charge is used
  • Toner is not water-soluble, so does not get smudged when wet
  • Toner is cheaper than inkjet printer ink

Disadvantages:

  • Expensive to buy
  • Toner is toxic
  • Colour production not as precise as inkjet printers
6
Q

How does a 3D printer work?

A
  • Makes a three-dimensional solid object of any shape from a digital model.
  • Some 3D printers use inkjet technology.
  • Others use lasers to fuse granules of plastic, metals, ceramic or glass.
  • It can also be done by successive layers of material being laid down in different shapes.
  • Construction of a model can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model.
7
Q

List some advantages and disadvantages of 3D printers

A

Advantages:

  • Can produce a wide variety of manufactured products, including customisable products and personal designs
  • Rapid prototyping
  • Fast manufacturing of printed products
  • Even though the initial setup costs are higher, 3D printing is becoming cheaper than cheap labour in third world countries
  • More Jobs: engineers to design and build 3D printers, technicians to maintain, use, and fix 3D printers
  • Potential in medicine to print customisable human body parts or organs

Disadvantages:

  • Currently, 3D printers only manufacture products out of plastic, resin, certain metals, and ceramics.
  • Printing of copyrighted products to create counterfeit items will become more common and nearly impossible to determine.
  • Easy to print dangerous items such as guns or knives
  • Currently, 3D printers are limited with the size of the products that they can create
8
Q

How does a 2D cutter work and where may it be used?

A
  • Use laser to cut precise patterns in most materials
  • Approx. 20mm limit for depth of the cut
  • Used in industry, for example to cut a sheet of metal
9
Q

List some advantages and disadvantages of 2D cutters

A

Advantages:

  • Quick way to cut through many different materials

Disadvantages:

  • The laser cutter can only cut on a single flat face and does not recognize the other faces of an object like a 3D cutter
10
Q

How does a 3D cutter work and where may it be used?

A
  • A three-dimensional laser cutter is like a regular laser cutter, except the laser is able to recognize all sides of a shape and not just the shape’s face.
  • Can be used to make models of objects
11
Q

List some advantages and disadvantages of 3D cutters

A

Advantages:

  • Can cut many different types of materials, such as glass, crystal, metal and wood.
  • Can be set to cut the inside of the material, allowing more complex shapes

Disadvantages:

  • Ordinary 3D cutters using a rastering motion do not allow for 3D shapes of the sort that have ledges or require undercutting, or any kind of cutting/machining that can’t be done from vertically above and perpendicular to the X-Y plane.
12
Q

How do speakers and headphones work?

A
  • An electromagnet causes a diaphragm to vibrate depending on the electrical current. The diaphragm’s vibrations causes the air to vibrate, which produces sound
  • Headphones and earphones are small versions of speakers designed to fit on or in your ear, used to prevent other people from hearing private content
13
Q

What are actuators?

A
  • An output device used for controlling a system, though it does not always provide output directly to the user
  • Usually paired with sensors that provide feedback to the control program
  • Actuators can act to affect the real-world depending on the signal or reading received
14
Q

What are flat panel display screens?

A
  • Very thin display screens
  • Small, light and easy to fit on a table or mount on a wall
  • The screens are backlit to make it easier to read
  • Different types include:
    • Liquid Crystal Display (LCD)
    • Light-Emitting Diodes (LED)
15
Q

How do Liquid Crystal Display (LCD) screens work and where may they be used?

A
  • Uses two sheets of material with a liquid crystal solution between them
  • Monitor’s control program scans and sends signals to individual liquid crystal pixels to allow certain amounts of light and colour to pass through
  • Used in some types of digital watches and PCs
16
Q

List some advantages and disadvantages of LCD screens

A

Advantages:

  • Sharp images
  • Zero geometric distortion at the original resolution of the screen
  • Bright images - best for brightly lit environments.
  • Consume little electricity and produce little heat
  • Immune to screen image burn-in

Disadvantages:

  • The colour and contrast from various viewing angles is inconsistent
  • Poor colour production of black and very dark grays - not suitable in darker environments
  • Motion blur is common
  • With brightness from backlighting, imagery may appear flat
  • Pixel-based display may be stuck on screen
  • Fixed resolution
  • Newer technology costs more
17
Q

How does an LED screen work and where may it be used?

A
  • Stands for Light Emitting Diode
  • A diode that glows when voltage is applied as the result of moving electrons
  • Allows the flow of current in a single direction only
  • Typically used outdoors in store signs, billboards or information screens
18
Q

List some advantages and disadvantages of LED screens

A

Advantages:

  • LEDs are much smaller than LCD fluorescent lamps so the screen itself can be made thinner and lighter — good for mobile phones
  • LEDs are high-efficiency light sources, and low power consumption leads to significant energy savings
  • Switch on rapidly, even when cold

Disadvantages:

  • The colour of white LEDs can be very inconsistent
19
Q

How does an LCD projector work and where may it be used?

A
  • An LCD projector is a video projector used to display images, videos and computer data on a screen or other flat surface
  • LCD projectors send light through a prism that separates light into three panels, red, green and blue components of the video signal
  • The images stack on each other on the screen to produce the image
  • Used in home theatres, school classrooms, etc.
20
Q

List some advantages and disadvatages of LCD projectors

A

Advantages:

  • Can achieve greater brightness at a lower energy consumption
  • Sharp image
  • Possible to achieve greater zoom magnification with an LCD projector

Disadvantages:

  • Because there are three panels, it is possible for one to fall out of alignment. This will cause one of the three stacked images to be shifted slightly.
  • Filters need to be cleaned periodically, causing an LCD projector to be more maintenance intensive
21
Q

How does a DLP projector work and where may it be used?

A
  • Stands for Digital Light Processor.
  • Uses a digital micromirror device, where microscopically small mirrors are laid out to create the image.
  • In a single chip DLP projector, colours are produced either by placing a colour wheel between a white lamp and the DLP chip or by using individual light sources to produce the primary colours, e.g. LEDs or lasers.
  • A three-chip DLP projector uses a prism to split light from the lamp, and each primary colour of light is then directed to its own DLP chip, then recombined and directed out through the lens.
  • Used in some cinema systems and large venue projectors.
22
Q

List some advantages and disadvantages of DLP projectors

A

Advantages:

  • Unlike LCD projectors, DLP screens do not rely on fluids and are therefore not limited in size by their inherent mirror mechanisms, making them ideal for increasingly larger high-definition theatre and venue screens.

Disadvantages:

  • May use more electricity, and generate more heat, than competing technologies.
  • People may be bothered by the “rainbow effect”, particularly in older models.