One of the biggest problems facing the widespread adoption of VR headsets is their form factor. Anyone familiar with the technology will have the image in their mind: a bulky binocular-like blob attached to you like the face-hugger of a Alien.
But Nvidia wants to fix this, and has just published a research paper in collaboration with Stanford University showing a concept for a pair of ultra-thin holographic virtual reality glasses.
First of all, let’s see why today’s VR headsets are so bulky.
Effectively, this is due to the magnifying glass principle of the VR display optics. According to the Nvidia and Stanford article, normal headphones work with the “target [enlarging] the image of a small microscreen”.
This requires a large distance between the two, increasing the size of today’s headsets to accommodate the technology.
Other techniques to reduce the gap between the lens and the microdisplay have been explored, such as so-called “pancake lenses” which reduce the optical path through folding, but this has its limitations, in this case, with the technology only supporting 2D images.
While researchers have tried other approaches, these often have their own drawbacks, including low resolution output.
What the Nvidia and Stanford researchers are proposing is different. Its concept is a near-eye holographic display that presents a 2D or 3D image for each eye, with a thickness of just 2.5mm.
So how did they achieve this?
Well, think of the gap between the lens and the microdisplay which, in regular VR headsets, is used to magnify images and create holograms. Instead of this approach, Nvidia’s VR headset concept uses something called a “spatial light modulator,” which creates a hologram right in front of the user’s eyes.
This image helps to summarize it:
Although that’s not all. To improve the image quality of the thin virtual reality goggles, the researchers used “artificial intelligence techniques” to be able to “accelerate the computation of computer-generated holograms.”
To put it another way, they approached VR screen quality and size as a computational problem, meaning they designed the optics using an algorithm to find the highest-grade output.
One of the article’s authors summed it up this way:
This ultra-slim design was made possible by new camera-in-the-loop optimization. Since the phase-encoded illumination is provided by the waveguide, conventional plane wave-based algorithms will not work. This is a great example of ‘Computing can reshape the screen’
[3/4] pic.twitter.com/LgVnIt1y2a— Jonghyun Kim (@jkim_kr_) May 4, 2022
It’s also important to note that the images you see of the ultra-slim VR glasses show a wearable prototype. As Jonghyun Kim, a senior research scientist at Nvidia, putsit is a “working demo, although the drive board, power, and light source were separated for the concept photo.”
As you would expect from a research paper from Nvidia and Stanford, there are a lot more details that I encourage you to dive into. You can read all about it here, plus watch a pretty helpful video here.
While we’re a long way from these slim VR goggles making it to market, work like this shows the future potential of the technology.
Virtual reality headsets have been around for some time, but they haven’t yet been fully accepted by the mainstream. One potential reason for this is the unwieldy form factor. I mean, current VR headsets just don’t look good, so getting people to use them is hard.
The more scientists can counter this and make VR headsets look like regular glasses, the closer we will be to making VR a part of our lives.
Whether that’s a good thing or a bad thing, I’ll leave it up to you, but it’s impossible not to be impressed by what scientists are accomplishing, as well as what the future holds.
If you’re intrigued about what other research papers Nvidia is publishing at SIGGRAPH 2022, you can find out more about it here.
Until then? Well, I hope to see you soon in a very comfortable virtual reality.
