Input Devices

Input Devices

Keyboard: most common and widely used.
1. Keys: Alphabet keys, Function/ F keys (F3), Numeric keys, Arrow keys and Command keys (insert,delete)
2. 'QWERTY'
3. Using for too long can lead to health problems - repetitive strain injury (RSI)
  1. Ergonomic keyboard has been created - hands in more natural position
A piece of hardware used to enter data into a computer
1. Manual input devices
2. Automatic input devices
Mouse: 'pointing device' enables you to control what happens (pointing, clicking, selecting items).
1. Two buttons and central wheel (scroll).
  1. Left button: choose menu item
  2. Right button: brings up list of relevant menu items
2. Advantages:
  1. Ideal for use with desktop computers
    1. Supplied as part of new computer system
      1. Most familiar with them - little training
        Works well in conjunction with keyboard for data entry
3. Disadvantages:
  1. Need flat space close to computer
    1. Rollers can become clogged with grease
      1. Overuse can lead to RSI
Touchpad: input device usually found on a laptop. Used in place of a mouse.
1. Advantages:
  1. Useful for laptops when using a mouse isn't practical
    1. Pads position is fixed
      1. Very short finger movements needed to move cursor
2. Disadvantages:
  1. Takes practice and skill to control position of cursor
    1. Gloves cannot be worn
      1. Moist and sweaty fingers can disrupt signals picked up the the sensors
Joystick: originally used by pilots -> computer games (more realistic). Move in many directions. Controls machines such as cranes, trucks
1. Advantages:
  1. Better gaming experience
2. Disadvantages:
  1. Some people may find them more difficult to control
    1. Not particularly robust, can break easily
Concept keyboard: contains grid of buttons that can be programmed to do whatever you want (can use symbols). Usually for when fast input is needed i.e. Fast food restaurant.
1. Advantages:
  1. Much faster for making non-text selections (menu)
    1. Waterproof - useful when risk of dirt and splashes
2. Disadvantages:
  1. Poor for text/numeric input. (some do have numeric keypad to show amount sold)
    1. Limited to options shown on keyboard
Touchscreen: only device that works as both an input and output device. View options on screen (output) then use your finger to touch option (input).
1. Advantages:
  1. Easy to use, not much training
    1. No extra peripherals i.e mouse are needed
2. Disadvantages:
  1. Not suitable for inputting large amount of data
    1. Not robust, can soon become faulty
Scanner: convert images/ text on paper into digital format. Shines beam of light then sensor detects colour that is reflected back and builds up image this way. (Flatbed and Handheld)
1. Advantages:
  1. Accurate and reasonably high quality
    1. Images can be enhanced once digitalised
2. Disadvantages:
  1. Take up a lot of memory space
    1. Lose some quality
Graphics tablet: Designer can produce more accurate drawings than they would with a mouse. Sensitive tip to have heavier or lighter lines
1. Disadvantages:
  1. More expensive than mouse
    1. Not suitable for general selection work
2. Advantages:
  1. Natural to draw with pen than mouse
    1. Great level of accuracy can be achieved
Magnetic Ink Character Recognition: Banks process cheques 300 per minute, 100% accuracy this way.
1. Advantages:
  1. Quick and very accurate
2. Disadvantages:
  1. Reader and Ink are very expensive
Optical Mark Reader: detect pencil by reflecting light (less light where the mark is). Sends results to computer (storage, analysis and reporting).
1. Advantages:
  1. Fast for inputting large amounts of data
    1. Much more accurate than humans
2. Disadvantages:
  1. May not be read correctly
    1. Not suitable for text
Optical Character Recognition: normal scanner and specialist software changes the letters into a form that can be edited/ processed by a word processor
1. Advantages:
  1. Cheaper than paying someone manually
    1. Much faster
2. Disadvantages:
  1. Not 100% accurate
    1. Documents need to be checked over
Magnetic strip reader: back of credit cards, loyalty cards.. It can hold personal details (60 characters). Swiped through magnetic strip reader machine - info fed top computer
1. Advantages:
  1. Simple to use
    1. Cheap to produce
2. Disadvantages:
  1. Limited storage capacity
    1. Data destroyed by strong magnetic fields
Barcode Reader: series of vertical bars - give information on country of manufacture, name of manufacturer, product code. Automatic input device
1. Advantage:
  1. Any price change only needs to be made to the database and not the packaging
Biometric Devices: Fingerprint and retinal identification, facial recognition. UK passport - microchip. But also ATMs, registration.

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	Erstellt von charcrawford vor etwa 11 Jahre