What are the current limitations of 180 FOV

[jsublime]

Hello,

I'm trying to understand why there isn't a technology out there which offers full field of view glasses. I mean, there are glasses which display a regular display 10 feet in front of the viewer. Why can't similar glasses enlarge the screen enough so that it covers the entire FOV?

What I'm thinking for example are glasses which have a display similar to IMAX. 3d can be introduced later, I'm just curious about the display.

Thanks!

[Fredz]

It's already been done in the past thanks to the LEEP optics invented in 1979, this technology has been used for most HMDs from the eighties (Cyberface, EyePhone, Flight Helmet, etc.) till the mid nineties, using FOV between 90° and 120°. Starting from the mid-nineties the FOV has largely decreased to 30°-56° (i-glasses, VFX1, CyberMaxx) and seems to be more in the 30°-35° for current HMDs.

I guess the technology has moved on to lower FOV HMDs because of the image distorsion, the low resolution of the displays and the heavy weight of HMDs due to the optics, but it's quite unfortunate since a FOV of 60° is genereally considered to be the minimum to feel immersion. When 4000x4000 2.5" LCD screens will be technically feasible I suppose we'll get bigger FOVs in HMDs.

[cybereality]

Seems mainly an issue of either short-sightedness or laziness on the behalf of current manufacturers. High-FOV headsets have been around for many years, it just seems no one can make them cheap enough or with good enough quality to be acceptable for the consumer market. I think the main issue is the optics, since we do have a whole slew good quality display technologies that could work in an HMD. If there were a bigger market for this stuff I'm sure someone would have done it, I don't think its a technical limitation. There is just not enough money. The only people that would buy it are some academic researchers and crack-pots like me. That is until Apple decides to bring out a headset (and they have several patents), then everyone will marvel at how magical and revolutionary it is.

[ERP]

With conventional optics it's pretty much impossible to have a wide FOV and a compact design.
HMD manufacturers for whatever reason seem to have optimized for small compact designs rather than wide FOV.

Now having said that there is some hope on the horizon, Holographic Waveguides make it possible to create a near eye display with wide FOV in a compact package. I know of a couple of manufacturers looking at this technology for AR applications, but nothing I've heard about is targetted at a short term commercial product.

[Fredz]

That Holographic Waveguide technology seems quite interesting. I have good hope for Virtual Retinal Displays too, but the problem is still the same than for wide FOV HMDs, ie. resolution vs display size.

[cybereality]

I still don't think this is a technical limitation. It is more about social perception and economics. People think wearing video headsets is "dorky", thus major CEMs will not invest the R&D to create a consumer device that will flop. And what we have is a few companies like Vuzix (who are honestly not in that great a shape financially) bringing out bare-minimum quality headsets, a bunch of sub-standard Chinese junk, and maybe a few boutique outfits catering to academia/medical/military on the high-end. Then there are wild-cards, like Sony, who will show off a cool headset at CES and then probably never bring anything to market. So what we really need is a fundamental shift in the public perception and acceptance of wearing video eyewear, and that is not going to happen with these low-res 30 degree FOV HMDs available today. First we need significantly better quality, without it becoming a huge helmet (which is what the public doesn't want and will never buy). At that point we need a major taste-maker like Apple to make wearing headsets "hip" with a fancy multi-million dollar media blitz and the mindshare to shape public opinion. A company like Nintendo could also cause this shift, if they brought out a portable gaming console that was just a pair of glasses and thats it (your body was the controller). We are just not at that point yet. It might make sense just to start building some DIY headsets because if we wait for these big companies it could be many years before we see that day.

[zacherynuk]

It's extremely hard to make a single modern microdisplay display, often less than 0.5" diag magnified enough to fill up a field of view past 40 degrees using conventional manufacturing techniques. Now that processing has evolved from micro-component to LCOS, actually making the displays large enough to be used in HMD's for wide FOV is the stumbling block, the precision in optical placement required is extremely difficult to engineer, especially cheaply.

Also, after sales support for a consumer priced device can very quickly swamp and devour a company, especially in this day and age of "if it doesn't work the minute I plug it in I want a refund + compensation 'cos they be my rights"

[Tone]

This illustration demonstrates why you need large lenses and therefore large displays in order to achieve very wide field of view. You're looking at a top view cross-section of the eyeball, lens, and display. The blue lines show the extreme periphery of an unmoving eyeball's horizontal field of view. The dim red lines demonstrate what happens when the eyeball turns to the left.

So... getting back to the unmoving eyeball. The lens (or multi-lens optics) is fairly close to the front of the eye, certainly as close as your sunglasses would be. The lens needs to have a diameter that is large enough to intersect the blue lines in order to allow us to see the display at that field of view. You must look through the lens for all possible angles, not around it!

Human anatomy permits extremely wide field of view because the eyeball can rotate around its center. The dim red lines show the maximum field of view with the eyeball turned to the left. Another problem is encountered: the lens must be bigger because the eye rotates around it's center, not around its own biological lens.

Perhaps the lens could be made smaller and moved closer to the eye? More problems occur. The turning eye issue becomes magnified. Also, the lens must be aligned much more precisely with the eyeball.

We could potentially solve the turning eye problem by fabricating the lens as a contact lens, but this would require a very high diopter lens to work properly with a small display; unfortunately beyond what is possible with current contact lens technology. Furthermore, since the display is not physically coupled to the contact lens nor the eyeball rotation, the display must still be large enough to encompass all the possible rotations of the eyeball. Finally, the contact lens approach makes it difficult to transition between the virtual world and the real world, as the contact lenses must be removed and applied each time.

Wide FOV is more of an optics problem than a "marketing" problem.

EyeballLens.jpg

[cybereality]

I don't know, I think people are going about it the wrong way. For example, right now I just took like 3.7" smart-phone (which I got for $0.01) and a $1 pocket fresnel lens. If I hold the fresnel about an inch from my eye, and the phone about 3/4" in front, then I get what appears to be around 60 degrees of FOV. And this has cost me $1.01 right here. And the screen is relatively clear, more than good enough to play a game or watch a movie (probably not to read a book, though). Why can't someone make something at least this good and sell it (maybe I should do that...)?

[Okta]

This illustration demonstrates why you need large lenses and therefore large displays in order to achieve very wide field of view. You're looking at a top view cross-section of the eyeball, lens, and display. The blue lines show the extreme periphery of an unmoving eyeball's horizontal field of view. The dim red lines demonstrate what happens when the eyeball turns to the left.

So... getting back to the unmoving eyeball. The lens (or multi-lens optics) is fairly close to the front of the eye, certainly as close as your sunglasses would be. The lens needs to have a diameter that is large enough to intersect the blue lines in order to allow us to see the display at that field of view. You must look through the lens for all possible angles, not around it!

Human anatomy permits extremely wide field of view because the eyeball can rotate around its center. The dim red lines show the maximum field of view with the eyeball turned to the left. Another problem is encountered: the lens must be bigger because the eye rotates around it's center, not around its own biological lens.

Perhaps the lens could be made smaller and moved closer to the eye? More problems occur. The turning eye issue becomes magnified. Also, the lens must be aligned much more precisely with the eyeball.

We could potentially solve the turning eye problem by fabricating the lens as a contact lens, but this would require a very high diopter lens to work properly with a small display; unfortunately beyond what is possible with current contact lens technology. Furthermore, since the display is not physically coupled to the contact lens nor the eyeball rotation, the display must still be large enough to encompass all the possible rotations of the eyeball. Finally, the contact lens approach makes it difficult to transition between the virtual world and the real world, as the contact lenses must be removed and applied each time.

Wide FOV is more of an optics problem than a "marketing" problem.

EyeballLens.jpg

Or we could just use a wider lens and display

[Tone]

Or we could just use a wider lens and display

Why bother with the lens? For the "size doesn't matter" crowd, just build yourself an IMAX theater setup. You'll be good for a full 180 deg.

[3dpmaster]

the solution for a wide fov is a hollow mirror instead of lenses.

[android78]

I think that simple tests like what Cyber mentions (the fresnel lens and cell phone) and what Palmer has done are proof enough that quite high resolution is doable. I think part of the problem is the user acceptance of larger HMD. It's cooler, if you like, to have a display that is barely bigger then glasses... and it's hard to sell the old 80's style HMD helmets.
The most promising technology that I've seen that could possibly be used for the small form factor that is mass marked friendly and could offer wide FOV is projection combined with waveguide technology. I think that consumer products using this are still a fair way off. And likely to start with low FOV and low resolution when they are first released.
It will get there... at least that's what I keep telling myself.

[PalmerTech]

the solution for a wide fov is a hollow mirror instead of lenses.

I agree with you, mirrors are a great solution when compared to lenses. You still need decent sized displays, though, microdisplays are a lot harder to do, maybe impossible.

[cadcoke5]

No one has mentioned curved OLED displays, which companies have been touting for at least 3 years. But, they haven't been appearing on the market. Perhaps there are technical reasons the demos never became a product, or perhaps it is just market demand.

But, regardless, this represents a way to create a large view area. Since the plastic substrate is very light, it doesn't have to be so close to the eye, and can perhaps the display be about 4 or 5 inches from the face. With this arrangement standard reading glasses are all that is needed. Yes, items outside the edge of the glasses will be blurry, but that is the way the world is for anyone who needs glasses.

It may also be viable to use a laser projector, but use a lens to spread the image, like they do in the spherical projections, only less severe;
http://eclecti.cc/computergraphics/snow ... projection

I am imagining a rough arrangement, sort of like the clear visor on safety helmets, like this one;
http://www.geckoheadgear.com/helmets/cu ... ety-helmet

While a moving demonstration would take a full set-up, a static test of the idea can be done by simply buying a strong pair of reading glasses for $1 at the dollar stores. Get the largest of the lenses, not the narrow type. Then, find a scenic picture, and bend it around your face, about 5" or so from your face.

Joe Dunfee