2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
The light field display allows the eyes to focus on virtual reality objects at different distances.
American startup Avegant has created a prototype of augmented reality glasses that use light field displays instead of a pair of traditional screens. Briefly about the new device tells The Verge.
Augmented reality usually means displaying information on top of real-world objects. Such technologies can be used to train doctors, play computer games, train soldiers, carry out work on board the ISS, and even in children's coloring books. However, in augmented reality glasses, users may have the problem of the lack of a low depth of field at the point where the gaze is directed, which is especially important when interacting directly with virtual objects. For example, if the user takes a virtual object in his hand and looks into the distance, the hand will be blurred, and the object in it will remain clear.
In order to make the image in AR glasses more believable, Avegant decided to use a light field display in their prototype. A light-field display is, in fact, a projector that does not display an image on a transparent screen, but directly into the eyes. Since it forms a light field, and not a "flat picture", the eyes can focus on virtual objects at different distances, just as it happens in reality.
The device developed by Avegant resembles Hololens glasses in appearance. At this stage, this is a rather massive prototype, which is connected to a computer using cables, and motion tracking has not yet been implemented in the glasses - that is, despite the demo, in fact, the device does not yet allow you to pick up any virtual object. The Verge journalists especially noted that the Avegant prototype has a significantly larger area in which augmented reality content is displayed. According to users who tested both devices, Hololens has an "AR window" the size of a deck of cards, while the Avegant has this area closer to the size of A5 paper.
It is worth noting that Microsoft started selling Hololens to developers last year, while Avegant did not name any timeframe for commercial implementation of the technology. Another niche competitor, Magic Leap, is in a similar position. The company has published several demos, but nothing is known about the appearance of the device, except for a schematic image from the patent.
To record the light-field image, special light-field cameras (plenoptic cameras) are used. Unlike conventional cameras, they record not only color and light intensity data, but also vector information about the direction of light. Thus, at the post-processing stage, you can change the depth of field in the frame both in photographs and in video. These cameras are commercially produced only by Lytro.
Previously, it was also proposed using a light field to solve the problem of focusing in virtual reality. Researchers at Stanford University have refined the VR glasses with an additional display. The second display outputs the image, corrected so that when the two LCD panels are superimposed, the output is a light field where the human eye can focus on a specific point in the image. The rest of the image at this time looks blurry, which is natural for human vision.
In addition to virtual and augmented reality, the light field display can be used in other devices. Researchers at the Human Media Lab at Queen's University in Kingston, for example, have prototyped a bendable smartphone with a light field display that allows a "holographic" smartphone to display a three-dimensional image that can be viewed with the naked eye by multiple users.
