Try it on the Oculus Rift or HTC Vive. You may first notice that the lens sees a fine concentric circle that creates what many people call "God Rays," especially when viewing high-contrast scenes. A new Facebook patent has just surfaced, and the patent aims to reduce such visual artifacts with a new hybrid Fresnel lens design.
Known as the "Hybrid fresnel lens with reduced artifacts" patent document, the new lens creates a larger surface area that is dedicated to standard non-Fresnel types, just like You may see it in heads such as Cardboard or even Samsung's Gear VR, but with a standard Fresnel-style ridge in the circle.
The patent was originally filed on September 13, 2016 and subsequently released at the end of last month.
Fresnel lenses are ideal for weight reduction. They offer large diameters and short focal lengths that make the lens comparable to traditional lenses, but weigh only a fraction of the weight.
Although they are thinner, they do introduce some visual effects that users are very annoying. They even modified the HTC Vive heads to accept Gear VR lenses.
Facebook's Oculus Rift is also released at the same time as the patent application. It is also equipped with a Fresnel hybrid lens. However, the appearance of the Rift is definitely better than many products on the market, including HTC Vive and the latest Google Daydream. .
Still, optical artifacts like "God Rays" still exist, ideally, as the display hardware matures, these things should disappear. Placing a traditional lens in the center of the earpiece's best viewing position (also known as "sweet spot") and moving the Fresnel ridge to the edge may strike a good balance between optical clarity and overall weight.
Indeed, many patents have never seen productization, and although we haven't noticed the company's legendary next-generation Rift, it's unclear what will happen in the future.