Download COMPUTER STUDIES Standard Grade

COMPUTER STUDIES
Standard Grade
OUTPUT DEVICES
Chapter 17
Standard Grade
Computing
PRINTERS
Laser Printer
• High quality printouts - can be in colour or B&W.
• Many pages can be printed very quickly.
Drum
• Toner is used to display the image on paper.
Inkjet Printer
Plotter
• Colour printouts
• Colour pens move up & down
• Excellent photograph quality
• Used with CAD packages
• Slower to print but less expensive
• Uses ink cartridges
Standard Grade
FOUNDATION
Computing
Monitors / VDUs
• A computer video
signal is received then
the image is displayed
on a screen
• More pixels per inch
means a higher
resolution
CRT
Ergonomic monitor
• A high resolution
monitor displays high
quality images
Standard Grade
FOUNDATION
Computing
MONITOR / VDU
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
Standard Grade
LCD: LIQUID CRYSTAL DISPLAY
• 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
Computing
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.
Standard Grade
GENERAL
Computing
•
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)
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GENERAL
Computing
Specialised Output devices
for Disabled users
Press a key to hear the
word spoken for the picture
VR Headset / VR Visor
Virtual Reality output
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CREDIT
Computing
MULTIMEDIA
HIGH QUALITY VDU NEEDED FOR
ANIMATION & MOVIE OUTPUT
Multimedia
White Board
Projector
HIGH QUALITY
SCREEN DISPLAY
HIGH QUALITY
SOUND OUTPUT
Standard Grade
CREDIT
Computing
Multimedia continued
Graphics Card
VGA (CRT)
output
ViVo
(video in/video out)
IMPROVES SOUND QUALITY OF
GAMES & MULTIMEDIA APPLICATIONS
DVI
(Digital Output)
CONTROLS THE QUALITY OF
OUTPUT ON A MONITOR
Standard Grade
Sound Card
CREDIT
Computing
And there are more….
Exciting chapters to follow
So tune in again next time
Standard Grade
Computing