2. With the massive development in the field of computer
graphics a broad range of graphics hardware and software
systems are available.
With personal computersâĻ usage of variety of interactive
input devices and graphics software packages
Higher-quality applicationsâĻ usage of special-purpose
graphics hardware systems and technologies
Introduction to Graphics Systems
3. ī§ VIDEO DISPLAY DEVICES
ī§ RASTER-SCAN SYSTEMS
ī§ RANDOM-SCAN SYSTEMS
ī§ GRAPHICS MONITORS AND
WORKSTATIONS
ī§ INPUT DEVICES
ī§ HARD-COPY DEVICES
ī§ GRAPHICS SOFTWARE
Graphics Systems
5. Refresh Cathode-Ray Tubes
Refresh CRT
ī§ Control Grid
ī§ Focusing System
ī§ Focusing in High Precision System
ī§ Construction of Cathode-Ray
Tubes
ī§ Persistence
ī§ Resolution
ī§ Aspect Ratio
10. Refresh Cathode-Ray Tubes
Refresh CRT
ī§ Control Grid
ī§ Focusing System
ī§ Focusing in High Precision System
ī§ Construction of Cathode-Ray Tubes
ī§ Persistence
ī§ Resolution
ī§ Aspect Ratio
15. CRT Displays
Advantages
īˇ Fast response (high
resolution possible)
īˇ Full colour (large
modulation depth of E-
beam)
īˇ Saturated and natural
colours
īˇ Inexpensive, matured
technology
īˇ Wide angle, high contrast
and brightness
Disadvantages
īˇ Large and heavy (typ.
70x70 cm, 15 kg)
īˇ High power consumption
(typ. 140W)
īˇ Harmful DC and AC
electric and magnetic
fields
īˇ Flickering at 50-80 Hz (no
memory effect)
īˇ Geometrical errors at
edges
18. Plasma-panel Displays
ī§ Similar in principle to
fluorescent light tubes
ī§ Small gas-filled capsules are
excited by electric field, emits
UV light
ī§ UV excites phosphor
ī§ Phosphor relaxes, emits some
other color
19. Plasma-panel Displays
ī§ Two glass plates separated
by neon gas
ī§ Vertical and horizontal
conductors
ī§ Very rugged
ī§ No refreshing
ī§ Screens can be transparent
and overlay documents
ī§ Used to be available in
monochrome (Orange)
ī§ Now available in colour
20. Plasma-panel Displays
ī§Advantages
âLarge viewing angle
âGood for large-format displays
âFairly bright
ī§Disadvantages
âExpensive
âLarge pixels (~1 mm versus ~0.2 mm)
âPhosphors gradually deplete
âLess bright than CRTs, using more power
21. Liquid Crystal Displays
ī§ Liquid Crystal Display
ī§ A transmissive technology
ī§ Works by letting varying
amounts of a fixed-intensity
white backlight through an
active filter
ī§ Organic crystals that align
themselves together
ī§ When external force is
applied they realign
themselves
ī§ This is used to change
polarisation and filter light
23. Liquid Crystal Displays
ī§ Transmissive & reflective LCDs:
â LCDs act as light valves, not light emitters, and
thus rely on an external light source.
â Laptop screen: backlit, transmissive display
â Palm Pilot/Game Boy: reflective display
24. Advantages
īˇ Small footprint (approx 1/6 of CRT)
īˇ Light weight (typ. 1/5 of CRT)
īˇ Low power consumption (typ. 1/4 of CRT)
īˇ Completely flat screen - no geometrical errors
īˇ Crisp pictures - digital and uniform colours
īˇ No electromagnetic emission
īˇ Fully digital signal processing possible
īˇ Large screens (>20 inch) on desktops
Liquid Crystal Displays
26. Three-Dimensional Viewing Devices
ī§Vibrating flexible mirror
ī§Stereoscopic and virtual
-reality systems
-shutter glasses (with tracking)
-headset with tracking
-other VR devices
ī§Holograms
ī§NC-mills + soft material
ī§Stereo-lithographic apparatus
(SLA)
27. Virtual reality = stimulation of the human senses to
simulate a fictive environment
eyes: private eye, head mounted displays (hmd)
ears: headphones, loudspeakers in hmd
tactile sense: data glove, data suit, treadmill
Virtual Reality Devices
28. âĸ2 small screens display
âĸimages for both eyes:
âĸhigh immersion degree
âĸhead movement controls
âĸvirtual camera
âĸartificial image only
âĸlow resolution (e.g. 256 x 210)
âĸvery expensive
âĸnarrow view-angle
Head Mounted Display