Facebook’s VR research department is presenting prototype VR optics smaller than any we’ve noticed but for the yearly SIGGRAPH computer graphics convention.
The concepts at the back of the “holographic near-eye display” may at some point allow VR headsets with sun shades shape factor- however for now that is only research with obstacles.
Why Are VR Headsets So Bulky?
The number one driving force of the dimensions and bulk of nowadays’s VR headsets is the optical design. Magnifying a show over a large box of view calls for a big, thick lens, and focusing it at a viewable distance calls for a protracted hole to the show. After including the housing had to include the program, even essentially the most minimum designs finally end up over 350 grams.
The standalone Oculus Quest, with a battery, cell chip and lens separation adjustment, weighs 571 grams. Many other people to find it hurts their face after a couple of mins.
Panasonic and Pico have proven off prototypes of compact headsets the usage of “pancake lenses”, and Huawei has already introduced this as a product in China. Without a monitoring machine or battery, those headsets finally end up round 150 grams.
However, those present pancake lens designs have numerous unsolved flaws. They block round 75 p.c of sunshine which may make the picture glance dim and washed out. They may additionally display faint ghost variations of the picture quite misaligned, and this “ghosting” handiest will get worse as you attempt to toughen the picture with a brighter supply.
Facebook Reality Labs’ new means is a skinny movie the place focusing is completed by means of holographic optics as a substitute of by means of the majority of the lens. ‘Hologram’ on this context simply manner a bodily “recording” of the way mild interacts with an object- on this case a lens relatively than a scene.
Facebook claims the research is also in a position “to deliver a field of view comparable to today’s VR headsets using only a thin film for a thickness of less than 9 mm.” The general weight of the show module is said as simply 18 grams. However, this doesn’t come with the true laser supply, and nor do any of the pictures Facebook supplied. “For our green-only sunglasses-like prototype, we measured an overall maximum field of view of approximately 92◦ ×69◦,” consistent with the research paper.
By the usage of polarization-based optical folding, those ultra-lightweight lenses will also be positioned without delay in entrance of the show supply.
Because holographic parts disperse mild, the one sensible illumination supply is lasers used at explicit angles and wavelengths. The researchers had been in a position to “inject” laser mild right into a 2.1″ 1600×1600 LCD, changing the backlight.
The prototype is these days monochrome, handiest able to showing the colour inexperienced. The researchers have a tabletop-sized evidence of idea for multi-color, and imagine bringing this to the sun shades prototype is “viable” with additional engineering.
The vary of colours laser mild can ship (referred to as the colour gamut) is considerably wider than LCD presentations, and in reality quite wider than even OLED, so this could constitute a milestone fulfillment if it might be moved right into a head-worn machine.
Early Research, Lofty Goals
It’s necessary to remember that what’s being offered right here is solely early research for a brand new more or less show machine. If it ever turns into a product, it’ll additionally desire a monitoring machine. And until it connects in your phone with a cable, it’d most probably desire a battery and cell chipset too.
Facebook describes this research as being at the identical miniaturization research “path” as Half Dome 2 and three, which it offered at Oculus Connect 6 again in October.
Those headsets are a lot higher than what’s being proven right here, however accomplished a much wider box of view whilst additionally having eye monitoring and variable focal point. FRL says long term iterations of this sun shades prototype may be varifocal by means of shifting the lenses on a spread of simply 1 millimeter. This may theoretically be accomplished with tiny piezoelectric actuators.
For virtual reality to achieve Mark Zuckerberg’s lofty objective of one billion users, headsets want to get considerably extra at ease whilst expanding realism. While designs just like the Rift S “halo strap” can redistribute weight, that is extra of a bandage than in reality addressing the problem of bulk.
Like all early research, this concept might by no means pan out. Practical problems might emerge. Facebook is concurrently exploring numerous novel compact show architectures. If it may well make even one paintings, it might do to VR what LCD panels did to CRT displays and televisions.
Facebook’s research paper concludes:
“Lightweight, high resolution, and sunglasses-like VR displays may be the key to enabling the next generation of demanding virtual reality applications that can be taken advantage of anywhere and for extended periods of time. We made progress towards this goal by proposing a new design space for virtual reality displays that combines polarization-based optical folding, holographic optics, and a host of supporting technologies to demonstrate full color display, sunglasses-like form factors, and high resolution across a series of hardware prototypes. Many practical challenges remain: we must achieve a full color display in a sunglasses-like form factor, obtain a larger viewing eye box, and work to suppress ghost images. In doing so, we hope to be one step closer to achieving ubiquitous and immersive computing platforms that increase productivity and bridge physical distance.”