Innovators in image processing

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• Innovators in image processing

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Principles of stereoscopic projection
Stereoscopic projection technologies

• The active system
• single CRT/DLP
• The passive systems
• double CRT with passive filters
• double LCD/DLP
• single CRT with Z-screen

3D
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Active stereoscopic projection
The active system
A CRT/DLP projector projects a left-eye image
and a right-eye image one after another _at_ 96Hz
or 120 Hz (per eye 48Hz or 60 Hz)
The Active Shutter Glasses make sure that the
appropriate eye sees the appropriate image
Synchronisation signal
From IG
CRT
EMITTER
Shutter signal to glasses
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Active stereoscopic projection
Active Stereo Advantages and Drawbacks

• Excellent Stereo Quality
• Any type of screen is appropriate
• CRT High resolution
• DLP High brightness
• Expensive Active glasses
• Darkened room needed (CRT)
• Low resolution (DLP)
• PWM artifacts (DLP)
• Only possible with special 3-chip DLP projectors

IR Emitter
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Passive stereoscopic projection (2 CRTs)

• Each projector displays image for 1 eye
• No need for fast phosphor
• For High resolution solutions
• Both projectors must be perfectly aligned and
  synchronized for true 3D image

Vertical polarizer
Horizontal polarizer
Left image projector
Non-depolarizing screen !
Right image projector
Vertical analyzer
Horizontal analyzer
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Passive stereoscopic projection (2 LCDs/DLPs)

• Extremely high light output, therefore ideally
  suited for 3D projection in high ambient light
  conditions
• Ideally for large audience performance
• Flexible mounting due to extensive lens range.
• Projectors need to be perfectly aligned
• LCD most efficient solution thanks to polarized
  light

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Passive stereoscopic projection (1 CRT/DLP and
Z-screen)
The Z-screen polarizes the light, synchronized
with the left-right image being projected on the
screen Need of a metallic / non-depolarizing
screen
synchronized
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Passive Glasses
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Linear vs. circular polarization

• Passive stereolinear and circular polarization

• Fairly standard,
• Excellent separation if well aligned,
• Sensitive to head tilt

• Requires adapted glasses
• Good separation
• Independent of head tilt

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Passive Stereoscopic projection
Passive Stereo Advantages and Drawbacks

• Cheap, comfortable passive glasses
• High brightness (LCD/DLP)
• LCD is very power-efficient solution
• Good Stereo Quality (dependent of polarizers and
  analyzers)
• Stereo Quality dependent of depolarisation ratio
  of the screen
• Tilting the head reduces 3D quality with linear
  polarizers

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Active pasive stereo conversion
Active mode - polarizers up dual light
output! Passive mode polarizers
down Non-depolarizing screens are
needed! Projectors need to be perfectly aligned
Motorized polarizers
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Generating 3D images

• Add an extra sync. Signal
• Top-Bottom
• Left-Right
• Interlaced (Odd-Even lines)
• Double Source

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Generating 3D images

• Image is split top - bottom
• top is left image
• bottom is right image
• double vertical frequency

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Generating 3D images

• Image is split left - right
• left is left image
• right is right image

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Generating 3D images

• Interlaced
• left image is odd lines, right image is even
  lines
• half resolution, normal refresh rate

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Generating 3D images

• 2 separate sources
• 2 synchronized DVD players, BETAcam tapes or
  Laser Discs
• Computer that generates 2 separate images, on 2
  cards/connectors

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Challenges of multi channel

• Why is CRT used so much?
• How can we use LCD in a multi channel
  environment?
• What about DMD?

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Curved screen - BR Center
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Why CRT technology in VAR Display Systems?

• active stereo capability
• Optimal for multi channel Curved Screens
• Flexible Real Time Geometry Correction
• Real Time Soft Edging
• Intrinsic color matching
• true black levels
• Double resolution (1440 x 1380_at_96)
• no image smear
• No Frame Delay
• No pixels

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Whats the Appeal of Light Valve?
Single screen presentations

• Plug it in and it works
• Connects to any source
• Single lens (automatic focus)
• Packages are getting smaller
• portable
• Maintenance replacing a light bulb
• ANYONE can use it
• ? Cheaper?

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CRT new products
BR 909 SP ( OEM)

• Same features as BR 909PLUS
• SP version installation flexibility
• OEM version easy access for alignment

• BR 912
• ONLY 220V.
• BW specs comparable to 909,
• Higher light output using 12 CRT tubes
• GLOBAL
• Auto-Image alignment system

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Conclusion

• The mature CRT technologytypical active stereo
  and multi channel display qualities justify the
  compromise on brightness and stability of
  convergence.
• The Light valve technologyadaptation for multi
  channel displays is done on higher end products.
  passive and active stereo is possible.Choice
  will depend on the application budget.
  Maintenance expectation

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Thank you for your attention...
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• Innovators in image processing