1. What is a stereoscopic display?

   A stereoscopic display is a display that presents a left image to the left eye and a right image to the right eye. This produces a 3D appearance that gives depth perception in the combined image. This powerful depth cue is called stereopsis.

2. How does Planar’s Stereo Display work?

   The SD1710 uses two AMLCD (active-matrix liquid crystal display) monitors positioned 110° apart. A half-mirror is setup at the bisecting angle between the two displays. Polarized light emitted from the bottom monitor is transmitted through the half-mirror. Polarized light emitted from the top monitor is flipped upon reflection off the half-mirror. Polarized glasses are used to restrict the left eye to view the bottom monitor and the right eye to view the top.

   The SD2020 and SD2320W work in a similar way; however, the type of LCD used requires some proprietary optical changes to the monitors and different polarized glasses than the SD1710.

3. What does the half-mirror do?

   The half mirror is actually a beam-combiner (or beam-splitter). It allows roughly 50% of light to be transmitted and it reflects the other 50%. The mirror is at the bisecting angle of the two displays, so that the images from the two monitors align in a virtual co-planar stereo image.

4. Why do users have to wear sunglasses?

   The glasses provided with the SD products are polarized in distinct orientations. The left eye lens allows only the image coming from the lower monitor to be seen. The right eye lens shows the top monitor image reflected from the half-mirror.

5. What is polarized light?

   Natural sunlight and most forms of artificial illumination transmit light waves whose electric field vectors vibrate in all perpendicular planes with respect to the direction of propagation. When the electric field vectors are restricted to a single plane by filtration then the light is said to be polarized with respect to the direction of propagation and all waves vibrate in the same plane.

6. Why is the StereoMirror technology better than shutter glass stereo monitors?

   Stereoscopic CRT (cathode ray tube) monitors display left and right images sequentially at a refresh rate of 100-120 Hz. The user can wear special goggles that have a liquid crystal shutter alternately blinking in front of each eye at 50-60 Hz, so the left eye can see the monitor when the right eye can’t and visa-versa. These active glasses are connected to the computer to synchronize the electronic shutters to the sequential frames on the CRT either with a tethered cable or infra-red beam.

   Another approach is uses a large pi-cell LCD that overlays the CRT screen. The emitted light is flip-flopped between clockwise and counter-clockwise circular polarized light. The operator wears passive polarized glasses. In either case, this shuttering can cause the image to flicker. The advantage of the SD monitors is that both eyes view image content continuously, which allows for much more comfortable viewing and significantly higher brightness. Additionally, most of the high-quality CRT monitors needed for shuttered stereo have been discontinued.

7. Why is it better than auto-stereo displays (prismatic or lenticular lens)?

   The auto-stereo displays send every other display column to one eye or the other. Not only does this cut the resolution (at least) in half, but it also makes the image look coarse and jagged. The SD monitors use the full resolution of the LCD monitor so the image quality is superior. They also do not have a restricting “sweet spot” like the auto-stereo displays. The SD units can be used simultaneously by multiple viewers, whether standing or sitting. Some auto-stereo displays integrate an expensive head position tracking system in an attempt to give a slight increase in the allowed lateral head movement. Another advantage over the auto-stereo monitors is that the SD products do not require complex software to divide up a stereo image. It easily interfaces via Open GL, Direct X or other common addressing.

8. How do you display stereo images?

   The basic answer for Planar’s StereoMirror technology is that you need to send a left eye image to the bottom monitor and a right eye image to the top monitor. There are several stereo modes that can be used for creating these left/right stereo images.

   Horizontal span treats the two monitors as one very wide monitor. For example, instead of addressing two 1600x1200 displays, it simulates one monitor that is 3200x1200. This mode is useful for PowerPoint slide shows or presentation applications that have a left and right image (or video) on each slide.

   For most OpenGL stereo applications, clone mode is used to send identical image to two monitors. When used in a stereo configuration, clone mode shows windows, menus, the desktop, etc. that appear identical on both displays, but the stereo viewing window of an OpenGL application can put a left eye image on one monitor and a right eye image on the other.

   Dual desktop mode treats the two monitors as two distinct displays that are showing different parts of a connected desktop. This configuration is often used with DirectX applications such as the 3mensio SW and a multitude of computer games that can be played in stereo.

9. What graphics cards can be used?

   This answer depends on the application being used. If the Stereo Display is to be used in a dual monitor mode, then any type of dual DVI output graphics card or cards can be used. OpenGL applications that uses clone mode will require a more specialized video card such as the nVidia Quadro line, the Wildcat Realizm cards from 3Dlabs, or the Matrox Parhelia or SDT cards. The nVidia GeForce line is a good choice for DirectX and PC game applications.

10. Does it require special software?

    The answer to this depends on what you are trying to do. The SD monitors can be used with any graphics, imaging or presentation programs to display left and right images. There are a host of software programs available that supports stereoscopic viewing. Application include molecular modeling, geospatial analysis, computer aided design, visualization SW and games.

11. Are there 3D games that work on the SD monitors?

    Yes, nVidia supports over 1000 computer games in stereo. These require an nVidia GeForce graphics card, the GeForce drivers and the nVidia 3D stereo drivers. Make sure that the video resolution setting in the game matches the display resolution for the two monitors.

12. What applications have been demonstrated on Planar’s Stereo Display?

    Company	Application
    3D Slicer	Open Source medical visualization SW
    3mensio	3viseon
    Accelyris	Discovery Studio Viewer Pro
    AGI (Analytical Graphics Inc.)	STK
    BAE	SOCETSET, SOCET GXP
    Boeing	Photogrammetry SW
    CAChe Group	CAChe workspace
    CambridgeSoft	Chem 3D Ultra
    DAT/EM Systems	Summit Evolution
    DVP-GS
    GEO CUE
    Intergraph
    IVS-3D	Fledermaus
    KLT Associates	Atlas
    Leica	ERDAS, Stereo Analyst
    Micro Vision Systems	stereo microscope video
    Microsoft	PowerPoint
    Overwatch Systems	Remote View
    Schrodinger	Maestro
    SolidWorks	SolidWorks
    Template Graphics Software	Amira

13. What is included in the price?

    The price includes the stand, two LCD monitors, cables/cords, half-mirror (beamsplitter), mirror-flip PCI card for inverting the video to the top monitor, five pair of polarized glasses, user manual, cleaning pads, 1-year warranty and technical support.

14. How do I switch from 3D stereo to 2D (monoscopic)?

    The simplest way is to turn off the top or bottom monitor. If desired, the half-mirror can be raised into a locked position to get it out of view. When raising or lowering the mirror, make sure that you slide it backward (raising) or forward (lowering) before moving it to a new position. You should not try to force the mirror. It will raise and lower with minimal force if it is first moved to the correct position.

15. How do I align the half-mirror?

    The SD monitors are aligned in manufacturing; however, taking a system apart, shipping it across the country, and putting it back together can altar the position of the half-mirror. There are two fine-adjustment screws under the edges of the half-mirror support arms. Rotating these screws will raise and lower the half-mirror. They should be adjusted so that the bottom and top images overlap as best as possible. It is more critical that the two images be aligned vertically than horizontally. A shift in the horizontal alignment will simply make objects look closer or farther away. Stereo alignment patterns are available on Planar’s product support website. Any simple grid pattern can be used for alignment when the two displays are in Clone mode.

16. What is the alignment tolerance?

    The alignment of the two stereo images is controlled by positioning of the monitors and the half mirror. We have found that alignment is more critical in the vertical direction than the horizontal direction. We adjust the hardware so that the vertical alignment is within ±1 display line. An offset left to right can simply make object look closer or further away. Still, we try to get the horizontal alignment to be with ±2 display columns.

17. How do I clean the mirror?

    Dust and debris can be blown off, preferably with compressed air. The thin film coatings on the glass can be cleaned with water, very mild soap or glass cleaner using a soft cloth such as the ones provided. Acetone, IPA, or strong acids or bases should be avoided. Do not use any abrasive material to clean the mirror or the monitors.

18. Do I need a special computer? Minimum level of compute power?

    Although there is no minimal compute power required to drive the Stereo Display, there may be limitations with graphics cards or special software. Use the specifications recommended by your software or video card provider. Obviously, a more powerful computer will allow large image files and 3D datasets to be manipulated more somoothly.

19. Can I build one from a kit? Can I use my own monitors?

    Planar is not selling StereoMirror kits. We provide a full stereo monitor solution using top-of-the-line Planar LCD monitors.

20. Can it be used as a projector?

    No.

21. Can it be used with a laptop?

    The StereoMirror technology requires a computer and graphics card that supports two external monitors. Most laptops only support one additional monitor and do not have a bus slot for adding an appropriate video card. There is a new Dell M90 laptop with an nVidia Quadro FX card that will support OpenGL stereo applications. There are also docking stations that have a PCI slot where the mirror-flip PCI card can be inserted. Some docking stations support multiple monitors, but may not support OpenGL stereo applications.

22. Why do I see a ghost image when I tilt my head?

    Light being emitted from the bottom monitor is at a polarization angle of approximately 130° (17") or 90° (20", 23"). Light from the top monitor is at a polarization angle close to 40° (17") or 0° (20", 23"). The polarized glasses are set up so that the left lens extinguishes light from the top monitor and the right lens extinguishes light from the bottom monitor (crossed polarizers block light). As the head is tilted to the side the ratio of linear polarizers do not line up as well to block the light from the opposite channel. When you see part of the left image in the right eye or the right image in the left eye this is called ghosting, bleed-through or leakage.

23. What is the stereo contrast and how is it measured?

    Contrast ratio of a standard 2D display is the white luminance (brightness) divided by the black luminance. The stereo contrast is the contrast ratio for the left image as seen with the left eye or the right image as seen with the right eye. The stereo contrast for the left eye is measured when the right screen is showing white. The stereo contrast for the right eye is measured when the left screen is white. The stereo contrast specified is the minimal contrast ratio seen from either eye in the center of the screen at a comfortable viewing position.

24. What stereo modes does it work in?

    The StereoMirror technology works with several stereo modes. Horizontal span, also called single desktop or Stretch mode, is when the graphics card treats the two monitors as one wide monitor. Clone mode sends the same information to the two displays, but creates a different viewpoint for the right and left images. Using the dual monitor mode treats the two displays as separate monitors and sends different information to each. The nView Clone mode should be used for stereo applications with the nVidia Quadro FX cards.

25. Does it work with openGL or DirectX?

    Yes, it works with both.

26. How and why is the video mirror flip accomplished for the top monitor?

    Because the user sees a reflection of the top monitor it is necessary to do a mirror inversion of the video going to the upper display. This can be accomplished in the drivers for the graphics card or in hardware. With each system, Planar supplies a PCI Mirror-Flip card that plugs into your computer. It receives a DVI signal in, flips the image one line at a time and send it to the top monitor. The PCI Mirror-Flip card does not require any special drivers and introduces insignificant (less than 50 microseconds) latency.

    There are also a couple of drivers under test that will eliminate the PCI Mirror-Flip card. Matrox has a solution for Clone mode in their Parhelia cards. nVidia has a solution for Dual Display mode in their GeForce cards. Planar has a solution for the Dome DX card that is used to operate Planar’s medical monitors like the C3 and C5i.

27. How transportable is the SD monitors?

    Planar can supply rugged shipping cases for transporting the any of the SD products. The SD1710 is separated into four parts (the base plate, the bottom monitor assembly, the top monitor assembly, and the half-mirror) for transportation. The SD2020 and SD2320W separate into three parts. The SD monitors are intended for desktop use.

28. What resolutions and sizes does the stereo display come in?

    The SD1710 is uses two high quality 17-inch LCD monitors with SXGA (1280x1024) resolution. The SD2020 uses 20-inch displays with UXGA (1600x1200) resolution. Planar’s wide-format SD2320W has two 23-inch screens with WUXGA (1920x1200) resolution for full-HD formats. There is a prototype version of the StereoMirror monitor using Planar’s C5i digital imaging monitors used for radiography and mammography with 5-megapixel resolution of 2560x2048 In the future Planar may offer other StereoMirror products.

29. Who would use a stereoscopic display?

    We have found interest from chemists, drug designers, photogrammetrists, cartographers, satellite image analysts, special ops groups, stereo photographers, CAD designers, architects, radiologists, mammographers, surgical planners, oil/gas explorers, PC gamers, stereomicroscope users, 3D modelers, complex data mappers and the list keeps growing. Anyone who looks at complex data and/or complex images may benefit from using Planar’s stereo display.

30. What is the size of the “sweet spot”?

    Users can move their heads up and down, right and left, and back and forth without compromising the stereo image. The only restriction to see a complete stereo image is that you must look through the half-mirror.

31. Why not setup the two monitors side by side instead of top/bottom?

    We tried this and it didn’t seem as natural and comfortable to view. It also takes up more desk space.

32. Can Planar use plasma displays with the StereoMirror technology?

    To use a plasma display, you would have to put a polarizer on the front, which would cut the brightness by more than half. Because plasma display already lack the full screen brightness of an AMLCD display this is not acceptable.

33. Do the SD monitors work in bright room light?

    Yes, there is adequate display luminance and contrast ratio to view the stereo image even in bright indoor ambient illumination.

34. Is there an adjustment for height or tilt?

    The current design does not allow for tilting, raising or lowering the stereo monitor.

35. How can people with prescription glasses view the SD1710?

    There are clip-on polarizers that fit most prescription glasses. It is also possible to have prescription polarized glasses made.

36. What accessories are available with the SD products?

    Rugged shipping case with custom foam inserts, extra polarized glasses and engineering samples of an external (stand-alone) mirror flip card box.

37. What is the standard warranty?

    One year on the stand and monitors. The mirror is covered for 90 days for optical defects. Although the mirror has a hard coat to resist scratches and is encased in a protective frame to protect against damage, the warranty does not cover scratches or breaks to the mirror caused by mishandling by the user.

38. Is there an extended warranty available?

    Yes. Additional two year or four year warranty coverage can be purchased. This would give the customer 3 years or 5 years of warranty protection. The price of this extended warranty depends on the SD model.

39. Can I use an SD monitor with a 3rd or 4th side monitor?

    Yes. This will require that a second graphics card be used with the computer. It is important that the second graphics card be compatible with the card driving the SD monitor and the application being run. For example, if you are running an OpenGL stereo application and using an nVidia Quadro FX PCIe graphics card to drive an SD monitor, you will need to use a second Quadro FX PCIe card to drive additional monitors. Otherwise the application may not operate correctly on all monitors. We would recommend using two nVidia Quadro FX PCIe graphics cards for OpenGL stereo applications where the user needs a side (mono) monitor. Older PC’s that use an AGP graphics card such as the nVidia Quadro FX 3000 can use a PCI bus graphics card such as the Quadro FX 600 to drive the side monitor. We have found that it is better to use the same generation of Quadro cards. For example, use the Quadro FX3700 with the FX1700. Use the Quadro FX3400/3500 with the Quadro FX1400/1500.

40. Why can I only see my side monitor in one eye with the polarized glasses?

    If the side monitor matches the polarization of one of the display used in the StereoMirror monitor, then you will only be able to see it with one eye when wearing the polarized glasses. A simple way to get around this is to select a monitor that has a different polarization. If you are using a SD2020, SD2420W or SD2620W, then we would recommend a Planar PL1911M, PL2011MW, PL2210MW, PX2211MW or PX2411W as the side monitor. Unfortunately, the only side monitor that has an appropriate polarization for the SD1710 is the Planar PX2611W, so it would be better to use the SD2020 or larger monitors in this workstation environment.

41. Does the StereoMirror technology work on a Linux box?

    Yes. This has been tested with nVidia Quadro FX graphics cards and the Linux drivers. Compatibility has been demonstrated with molecular modeling software from Schrödinger (www.schrodinger.com) and oil & gas exploration software from Paradigm (www.paradigmgeo.com). See the nVidia website for installing the drivers. Make sure the two monitors have the identical configuration and the “TwinView” option is selected. Use “Clone” for the “TwinViewOrientation”. The “Stereo” option should have “4” selected while the “AllowDFPStereo” option is “Yes”.

42. Does the StereoMirror technology work with Sun workstations?

    Yes. The Sun XVR-2500 graphics accelerator supports OpenGL stereo with Planar’s stereo monitors. Clone mode should be used for the stereo viewing mode.

43. Does it work on Macs?

    nVidia has drivers that support OpenGL stereo on their Quadro cards with the latest version of Tiger. The nVidia stereo support only covers applications that also support the nVidia stereo modes.

Optimized transflective displays result in:

• Excellent viewability over all ambient light conditions
• Lower Power
• Less Heat
• Extended Lamp Life

Related Content

• Stereopsis: Two Eyes, One 3D Image
• Exploring 3-D display technology
• 20 Reasons Why Planar's StereoMirror Offers Superb Stereoscopic Viewing (pdf)