Virtual Reality and Augmented Reality (or Mixed Reality) headsets have evolved quite a bit over the last few years. Improvements in resolution, lag, and other factors, have led to new, extremely immersive systems such as the HTC Vive. Hovewer, one missing feature is still holding back the technology:
Generally speaking, most of today’s displays consist of a two-dimensional display that’s placed at a fixed distance from the user’s eyes. This creates a conflict for our eyes and brain, which in the real world are used to a linked adjustment of the angle between the eyes (“vergence”) and the focus plain (“accommodation”). Recent proof-of-concept systems use up to three display planes, allowing us to experience discrete near, mid-range and far layer to focus on, but for a better, more immersive 3D experience we’ll need the ability to experience at almost continuous focal range.
The most promising solution to this problem is light field technology: For instance, Nvidia’s light field display prototype has shown successfully (though at low resolution) that it is possible to construct a light field image that allows placement of multiple objects at different focal planes or virtual distances. The Nvidia prototype uses a microlens array, much like in light field cameras from Lytro or Raytrix. Magic Leap is another company working on light field technology. While the company has teased a head-mounted light field display on several occasions, they have yet to explain how exactly their system works, let alone present a working prototype to the public.
Now, another company has entered the light field space. Head-mounted display maker Avegant has announced a new display that uses “a new method to create light fields” to simultaneously display multiple objects at different focal planes. While all digital light fields have discrete focal planes, according to Avegant CTO Edward Tang, the new technology can interpolate between these to create a “continuous, dynamic focal plane”. “This is a new optic that we’ve developed that results in a new method to create light fields,” says Tang. Continue reading
Light field technology that’s currently available, like the Lytro Illum or Raytrix’ industrial light field cameras, is largely based on microlens arrays which allow the flat imaging sensor to infer the direction of light rays in addition to their colour and intensity. While Raytrix has managed to ramp up spatial resolution to 25% of the actual sensor resolution by way of a customised, heterogeneous microlens array, effective resolution is still a limitation of today’s light field cameras.
Now, researchers at the Nanoelectronics and Nanophotonics Lab, University of Michigan, have announced working on a different approach that would allow capturing complete light fields at full sensor resolution. Rather than microlenses in front of a standard imaging sensor, the team around Zhaohui Zhong are developing a new sensor consisting of several transparent light detectors based on graphene, a material consisting of a single layer of carbon atoms. Continue reading
Light field imaging has captured the mind of many technology enthusiasts and imaging pioneers, and there have been rumours of light field cameras in future iPhones or Android smartphones.
Now a new patent has surfaced that shows Apple is still interested in light field cameras. The twist is, the proposed “plenoptic” (a.k.a. light field) camera system is intended to aid robots in the manufacturing process. Continue reading
Earlier this week, Lytro announced a new product which takes the company into a new direction: The Lytro Immerge is a futuristic-looking sphere with five rings of light field cameras and sensors to capture the entire light field volume of a scene. The resulting video will be compatible with major virtual reality platforms and headsets such as the Oculus Rift, and allow viewers to look around anywhere from the Immerge’s fixed position, providing an immersive, 360 degree live-action experience.
The authors of “Displays: Fundamentals and Applications”, Rolf R. Hainich and Oliver Bimber, have recently made their book available online. In chapter nine, they take a comprehensive look at various 3D display technologies including light field displays.
The 599 page long book, which sells for 83 US-Dollars in Hardcover form, can now be downloaded free of charge for non-commercial purposes as a 64 MB PDF at displaysbook.info (under “Materials”).
Our book “Displays: Fundamentals and Applications” is now available free of charge for non-commercial purposes.
You can download the ebook (pdf, 599 pages, 360MB) from http://displaysbook.info (Material). The hardcopy can still be ordered from CRC Press.
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