Almost everyone has seen, or heard of, 3D television shows or theme park
attractions. Unfortunately you've had to wear special glasses to experience
these three dimensional images. Not anymore. Companies are developing
display technologies that remove the need for glasses.
Desktop
Displays
Actuality Systems,
Inc
Actuality
presents a different approach to a desktop autostereoscopic display
than the other vendors. They believe you should be able to walk 360
degrees around the display and see a life size three dimensional image.
This is obviously not possible with a 3D monitor.
The Perspecta® display will complement a computer monitor instead
of replacing it. Initially the maximum viewable size will be about 10".
The raster-scan display renders high resolution, volumetric, images
in real-time.
The Perspecta® display works by projecting thousands of 2D images
per second onto a rotating screen. This is sometimes referred to as a swept volume display. Similar to television the eye fuses
these images together to create a seamless image. The downside to this
method is that you can't actually "touch" the image, but hey,
we won't be greedy. Maybe they'll figure that out in a few years.
Perspecta® is available for purchase. For more information visit
Actuality's web site.
A.C.T Kern
Their desktop LCD displays are autostereoscopic so they don't require glasses to see the 3D images. Vertical lenticular lenses direct discrete images to each eye and eye tracking adjusts on the fly the keep the viewer in the sweet spot. The web site has a good amount of detail describing the Free2C technology and applications.
Deep Video Imaging
Ltd. (this company doesn't seem to exist anymore)
Deep Video Imaging's 3D display, called actualdepth,
uses layered LCD panels to create the illusion of depth. They appear
to be targeting kiosks and point of purchase displays instead of computer
desktops like some of the other developers. Also, it appears that Deep
Video Imaging doesn't manufacture the displays themselves. Instead they
sell to OEMs.
The technical term for this technology is "autostereoscopic 3D
imaging."
DTI calls their product line, Virtual Window™ and in July 2007 a 19" display is available for $3695.
The following paragraphs are from DTI's web site. They describe the
concept behind the displays and one of DTI's competitive advantages.
"Our basic technology has been reduced to a single active substrate
that inserts between the LCD and its backlighter. When turned on it
allows the display to show real 3D images by creating light lines. These
light lines are placed behind a conventional LCD panel."
"The ability to convert instantly from 3D to 2D display is
the characteristic that makes DTI displays unique in the world: no other
3D display (there are only a couple) converts to full resolution 2D."
Dresden 3D GmbH (assets have been aquired by SeeReal)
The Dresden 3D
Display (D4D) is an 18.1" TFT LCD like the largest Virtual
Window from DTI. Eye tracking means viewers have the freedom to view
3D images from various angles. Some other designs don't allow this same
level of flexibility.
D4D can operate as a primary monitor, like DTI's display, with any
video card, but Dresden is also marketing the D4D as a secondary display
that will compliment a normal monitor. Because of this Dresden optionally
bundles a FireGL 3 graphics board with the D4D. The FireGL 3 is capable
of driving two displays simultaneously. A keyboard shortcut will toggle
the 3D display on and off when two displays are used. Another feature
of the FireGL 3 is that any OpenGL program can be set to output stereo
3D images to the D4D.
Holografika
The feature list for the HoloVizio
line of displays is impressive. Like most of the displays mentioned
here HoloVizio boasts true 3D with the naked eye. But, it's the other
features that stand out.
- Viewers
can walk around the screen in a wide field of view seeing the objects
and shadows moving continuously as in the normal perspective. It is
even possible to look behind the objects, hidden details appear, while
others disappear (motion parallax). Each image visualized by Holovizio contains an equal amount of information to almost 100 conventional 2D images.
- Unlimited number of viewers can see simultaneously the same 3D scene
on the screen, with the possibility of seeing different details
- Objects appear behind or even in front of the screen like on holograms
- No positioning or head tracking applied
The displays are currently available in 32" (16:9) and 26"
(4:3) sizes.
This article contains some videos and description of HoloVizio.
LightSpace Technologies
The DepthCube Z1024 3D display consists of 20 stacked LCD shutter panels that allow viewers to see objects in three dimensions without the need for glasses. Video is projected through the LCD shutters. Unlike auto-stereoscopic displays, DepthCube technology doesn't limit the field of view allowing multiple people to experience the 3D effect simultaneously. It also "provides both horizontal and vertical parallax-allowing the viewer to look around foreground objects to reveal previously obstructed background objects." More details of the technology are presented in 3-Deep from IEEE Spectrum.
The DepthCube InterceptorT application allows the Z1024 to intercept OpenGL data and effectively slice it for display across the stacked LCD panels. It is unclear if all OpenGL applications are supported.
Phoebe Ltd.
Update: Phoebe Ltd.'s web site is unavailable, but the company says a new web site is being constructed.
Viewing 3D holograms that float in mid-air without the need for special viewing equipment like glasses is a dream shared by many. A London based company called Phoebe Ltd. claims to have achieved this dream and they are in the process of commercializing their technology (2006). Here are some highlights from Phoebe's website.
P-3Di presents a holographic image outside of a physical device which is capable of being viewed in any light without the need for special eyeware.
The P-3Di System produces a crisp, bright coloured 3D holographic moving image that hovers in mid air between 5cm and 1 metre from source (bespoke systems can be designed to project images further than 1 metre if required) . Display units can vary in size from 10cm to 6 metres.
Phoebe is targeting an array of markets ranging from defense to cell phones with units that range in size from mobile phone to 6 meters square. A key feature of Phoebe's technology is the interactivity.
Our P-3Di Display has a unique motion detection system, which allows the user to interact with the 3D holographic image.
Polaris Sensor Technologies
At this time Polaris is unique in using polarization with a desktop sized display. Their method stacks two LCDs and uses polarization to direct the appropriate image to each eye. This is the same method used at amusement parks like Disney World so if you've been to a show there and worn clear glasses you know what kind of quality to expect.
The downside to polarization is the need for polarized glasses, but given a comfortable pair the high quality might be worth the cost. You can already buy cheap polarized sunglasses that look good and are comfortable so it shouldn't be too hard to convince people to wear another accessory for short periods of time. Many of us already wear headphones without complaining.
Polaris is mainly targeting professionals and military applications, but if they are able to arrange a partnership with a big display manufacturer like Sony or Hitachi the high volumes could drive down the price enough to make it palatable for home users to watch movies and play games. The main cost increase over today's LCD monitors is the second panel.
Polaris' web site briefly explains the various 3D display technologies in use today giving some pros and cons for each approach. It's a good refresher even if you are somewhat familiar each technique.
Reachin
While
it's not autostereoscopic the Reachin
Display is still some cool technology. It more than just a display
too, it's an entire user interface, including input. The goal is to
allow the user to "see and feel the object in the same place."
Here's how Reachin describes the display.
The Reachin Display integrates a PHANTOMT force feedback device
from SensAble Technologies with stereo monitor and supporting systems.
The innovative use of a semi-transparent mirror creates an interface
where graphics and haptics are co-located - the user can see and feel
the object in the same place!
The display is available in two versions. To get a better understanding
of how the system works check out this concept avi
file (3MB).
SeeReal
In May 2007 SeeReal demonstrated their prototype holographic display at the Society for International Display (SID) forum in California. As of July the product's still not available to buy, but SeeReal has licensing information on their web site.
SenseGraphics
The 3D MIW, or Mobile Immersive Workbench, is like a mobile, yet autostereoscopic, version of the Reachin Display mentioned above.
It integrates standard off-the-shelf hardware components such as SensAble Technologies haptic device and Sharp's PC-RD3D autostereoscopic laptop to offer a complete solution that weighs in at under 10kg (22lbs) and costs less than $10,000 including advanced software development tools.
SenseGraphics' open source haptic API, called H3D, allows developers to add haptic support to their software.
Some other players are 4D-Vision, Genex
Technologies, Sanyo, and StereoGraphics.
Philips is currently working with developers who wish to incorporate 3D
into their applications. When this article was written no information
was available on Sanyo's web site concerning the availability of their
3D display. Sharp should have a product ready soon. Genex's display appears
to be similar to Actuality's, but no technical information is available
on their web site.
Currently 3D LCD's are only practical for businesses that focus on entertainment
and product design, but the recent price drop on DTI's 15" display
means that soon the average consumer could have one sitting on their desktop.
New York University (NYU) has a neat
demo that shows two possible implementations of glasses free 3D displays.
Viewing these demos is the easiest way to grasp the concept behind 3D
LCDs.
- Viewers
can walk around the screen in a wide field of view seeing the objects
and shadows moving continuously as in the normal perspective. It is
even possible to look behind the objects, hidden details appear, while
others disappear (motion parallax). Each image visualized by Holovizio contains an equal amount of information to almost 100 conventional 2D images. 
The 