I'm trying to head back to the land of the electronic for a while, with that, however...
I decided to poke my nose into head mounted displays. I've always wanted to have a small glasses or otherwise transparently mounted information display. Not all the time, but enough. With my service job, being able to display the readout of my DMM or oscilloscope directly into my vision would be absolutely fantastic.
So, what's available?
Let's start with the "near mortal" components.
Ignore the marketing images, they don't do this product justice. This is perhaps the finest binocular HMD available. $400 is a bit steep for a QVGA display headset, but don't let the Star Trek visor design fool you. Micro Optical focuses on minimum occlusion display technology. That, translated, means it obscures as little of your vision as possible. This bar design allows you to see a lot above and below the displays, and the rest is actually tinted transparent, so you can see around the displays, too. The result? From the reviews I've read, it means you can actually wear them and use them without feeling any more strain on your eyes or stomach than a standard desktop LCD.
Apparently the design is rugged and lasts 6 hours on 3 AAA's (and the special IPod version runs on a custom lithium-ion in the special ipod case). The optics are a single fused block, so no worries about alignment.
Picking up where the original 3D headsets left off, 3DVisor is trying to bring high quality HMDs to a wider population. Yes, you do get the same disorientation issues as all enclosed HMDs provide. However, these aren't QVGA. These aren't VGA. Yes, they're full SVGA and have a VGA connector. Normally units of this resolution are $1000 to $2000. They're now selling this for $550. Rumor has it that they're going to be releasing an XGA (1024x768) model in the near future. Given that they were originally selling the current version for $900, the price break signals that both the OLED technology is maturing and that the future XGA model may break the $1000 barrier. XGA HMDs have been the realm of the military and research institutions and still traditionally cost as much if not more than a new car. I can't wait to see.
I linked directly to their Cyberdisplay section. Kopin is behind many low cost HMD hardware designs. I wouldn't doubt many of their displays have shown up in the $200 bargain basement HMDs. I know their displays (black and white) have shown up in camera, kid's night vision, and currently kids nightvision on an R/C car.
Now, most of these were black and white components. While I love hacking, sometimes you have to start from scratch. And where does that get me? Kopin sells both the main components (LCD, backlight, driver chip) and prepackaged assemblies (monocle display, binocular displays) for QVGA and VGA. The QVGA monocle (no VGA version, though) interests me as a possible core component to building a HMD. No driver chip, so it's going to cost almost as much as the VGA binocular arrangement, but that's how things work. You get twice the product for half the price with HMDs.
And in the future?
I ran across Microvision a year or so ago. At that time they were making high end HMDs for the military and had one $5000 red Nomad monocle. Sounds like a lot. They have a secret. They're the only group that I've seen that has an analog control 2D MEMS micromirror. I've seen the TI DLP hardware, that's pretty much a digital system, it's either pointing here, or pointing there. Microvision had used this to build the Nomad, and it let them put up any resolution they wanted to at extremely high framerates. Cost of the laser component and driver were the limiting factors. Apparently they've gotten over that. They're now working on integrating a fully working RGB laser MEMS projector system into things like car HUDs and cell phones. It's only a matter of time before the projector becomes available then. If it doesn't need any complex optics to work, this may be the best option to project an on-glass transparent HUD for a mobile user. The IPM looks quite small and hopefully inexpensive. Who knows, you might be able to pick up an XGA full color display for $100 at your local electronics shop in a year or two.