COMPUTER STUDIES Standard Grade

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COMPUTER STUDIESStandard Grade

• OUTPUT DEVICES
• Chapter 17

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FOUNDATION
PRINTERS

• Laser Printer
• High quality printouts - can be in colour or BW.
  
• Many pages can be printed very quickly.
• Toner is used to display the image on paper.

• Inkjet Printer
• Colour printouts
• Excellent photograph quality
• Slower to print but less expensive
• Uses ink cartridges

• Plotter
• Colour pens move up down
• Used with CAD packages

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Monitors / VDUs

• A computer video signal is received then the
  image is displayed on a screen
• More pixels per inch means a higher resolution
• A high resolution monitor displays high quality
  images

FOUNDATION
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MONITOR / VDU
LCD LIQUID CRYSTAL DISPLAY

• CRT CATHODE RAY TUBE
• Inside the flat end is coated with substances
  which glow when hit by electrons
• The coating has red, green blue dots which glow
  to produce the colours needed

• Transistors charge liquid crystals between two
  glass plates.
• Fluorescent tubes provide the light source, which
  passes through a layer of crystals.
• Varying the electrical charge to the crystals
  creates images.

GENERAL
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MONITOR / VDU continued
TFT THIN FILM TRANSISTOR

• LCD TFT monitors emit less radiations than a
  Standard LCD.
• AND emit MUCH less radiation than a CRT monitor!
• TFT also gives a picture up to an 80 degree
  angle.
• where as a LCD only goes to about a 45 degree.
• TFT also gives a sharper picture.

GENERAL
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Comparing Printers

• Capital Costs
• Determined by the quality of hardware bought
• e.g. laser or inkjet printer? CRT or LCD monitor
• Running costs
• Determined by what is used to operate the
  hardware
• e.g. printer paper amount quality, ink or
  toner?
• Speed
• How many pages are printed per minute (ppm)
• Resolution
• Determined by how many pixels or dots are
  present in each inch (dots per inch - dpi)

GENERAL
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CREDIT

• Specialised Output devices
• for Disabled users

Virtual Reality output
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CREDIT

• MULTIMEDIA

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Multimedia continued
CREDIT
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And there are more.

• Exciting chapters to follow

So tune in again next time