Supply Chain Market Research LLC
October 7, 2020
What’s happening around the world in the PC and mobile supply chain and who it affects…
- Making Waves
- Vizio OLED TV
- Qualcomm branded gaming smartphone?
- On again, off again
- “Phone, Heal thyself”
AR and VR have promise as potentially game changing display technologies, but so many promises have been made about how the world will be changed by the idea of being able to be in an immersive or augmented reality environment, and so few have been realized, that at times we wonder whether we will ever come to a point where AR/VR is able to become a viable medium. That said, the biggest complaint that most average people have about AR/VR is that they either get fatigued quickly or they get something akin to motion sickness. There are many possible reasons for this to happen, but the underlying cause is the fact that unless most people are placed into a virtual environment that duplicates what they see naturally, their brain is unable to process the visual information correctly, leading to the aforementioned issues.
The brain takes cues from all of the body’s senses but visual stimuli are the most important to the average person, with the human field of view (how far horizontally you can see without moving your head) is ~210⁰ and vertically ~150⁰, but in reality binocular vision, the ability to see depth, has a FOV of ~115⁰ in humans, which means what you might see outside of that 115⁰ window would not include depth information or full color information, which is concentrated in the middle of your FOV.
In daily life the brain uses all this ‘known’ information to build a visual image, but in VR not all of those cues are available, particularly the FOV, which in most VR headsets is limited to between ~37⁰ and 43⁰ due to the very short distance between the eye and the display. Things that happen outside of that perceived range can reduce the brain’s ability to structure an image, which causes fatigue or motion sickness. A limited VR FOV is not the only thing that can cause these issues, as poorly designed VR content or low-resolution displays can also miscue the brain, but FOV issues are extremely common and leave somewhere between 40% and 80% of people to have these issues when they experience VR.
VR displays have been improving. They are faster, meaning there is less time between when the screen is black and when it is light, they have higher resolution, so the spaces between pixels are smaller (the brain gets confused when it ‘sees’ missing information), but because they are so close to one’s eyes the narrow FOV remains a problem. Enter the world of waveguides. Waveguides are simply any structure that restricts the flow of energy by focusing it in one direction. Energy sources, be they sound, optical, radio frequency, or almost anything else, tend to be spherical, with the power of the energy dropping off at the rate of the square of the distance from the source. Waveguides force the energy to go in only one direction, which, in theory, means that it loses no power in the waveguide.
A simple cardboard tube is a waveguide for sound, which bounces off the inside of the tube until it reaches the end, and so is fiber optic cable, where light moves down the fiber, reflecting off the interior, with only a small amount of radiated loss. So where do waveguides come into play in AR/VR? Waveguide systems are among the best approaches to keeping AR/VR devices small and light with a wide FOV, and while they look the same as a piece of glass, they have the ability to take a small projected image and expand its size and then project it onto the eye of the user. This is accomplished by a number of possible methods, although nanoprinting lithography, where the ‘gratings’ that capture the light and direct it, are pressed into an organic resin and are ‘set’ by exposure to heat or UV light, seems to be the most mature and economically practical.
While the use of nanoprinting to make waveguides sounds like it can solve a number of major VR issues, as with any waveguide, the materials from which it is made determines how well it works, in this case the higher the refractive index of the material the wider the FOV, balanced against the material’s energy absorption, which would increase the need for a higher brightness source and higher power consumption.. All in, there are a number of companies, both large and small, that are actively developing waveguide products that can move the AR/VR world closer to commercial status. Most are small VC and partner backed companies like Nanocor (pvt), Pixelligent (pvt), and Nanophase (NANX) but while micro-display producers strive to increase pixel count and micro-projector companies try to keep size and weight to a minimum, nano-imprint waveguide technology continues to improve, giving us some hope that one day we will be able to actually use an AR/VR system that does not confuse our already overloaded brains with unrealistic information.
Andrew M. Abrams, Principal, SCMR LLC
Supply Chain Market Research
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