Frequently Asked Questions
SEOS HMD 120/40

1.  What is the display technology used in the SEOS HMD 120/40?

The 120/40 uses reflective liquid crystal displays. It does not use CRTs and there are no high voltages.

2. What trackers work with the 120/40?

There are no known incompatibilities between the 120/40 and trackers made by Intersense, Polhemus, Ascension, or Origin Instruments.  The tracker is conventionally mounted to the top surface of the rear of the unit.  The user software should be modified to correspond to the position of the tracker.  We can integrate a tracker of your choice with the unit.

3. What adjustemts are provided for in the 120/40?

There are adjustments for eye spacing and, for eyeglass users, +/- four diopters of focus compensation for each eye, independently. The focus compensation is suitable for about 95% of eyeglass users. The maximum head size that can be accommodated is about 8.25 inches.

4. What are the requirements for an image generator to drive the 120/40?

There are two 1280 x 1024 video inputs. The video inputs must be genlocked; synchronized to the pixel level. The video timing must be adjustable to meet the display timing requirements.  Current PC graphics accelerator cards including the ATI Radeon 9700, the NVIDIA GeForce FX and the Matrox Parhelia have dual video outputs meeting the requirements. The image generator software should be set up with window matrices such that the left eye must has a frustum of 80 x 67 with -20 heading offset (rotated to the left), and the right eye is 80x67 with +20 heading offset (rotated to the right). The left and right viewpoints are displaced by the eye separation.

5. What are the video timing requirements for the display?

The set up and timing requirements are specified here. NVidia boards timing can be adjusted using the PowerStrip software from www.entechtaiwan.com

6. Can users wearing eyeglasses use the display?

Eyeglasses cannot be worn, because the eye relief  of 12 mm does not accommodate the lenses.  The relatively shallow eye relief is necessitated by the very wide field of view.  The provided focus adjustments accommodates 95% of eyeglass users.

7. Is a see-through version of the display available?

No, there is currently no see-through version.

8. How can I obtain a demonstration of the display?

Please contact CGSD to arrange a demonstration.  E-mail rlatham@cgsd.com or call 650-903-4920.