Two different light field technology combinations were used by researchers to create large-scale 3D images at a fraction of the resolution required. This is their optical setup. Credit: Byoungho, Seoul National University
A prototype display has been developed by researchers that uses projection to create large-scale 3D images of high resolution. This new method overcomes the limitations of light field projection and can produce natural-looking 3D images without the need for special glasses.
Byoungho, a researcher at Seoul National University in Korea, said that "our optical design could make it possible to replace 2D flat panels displays with 3D images for digital signage, entertainment and other applications where 3D imagery provides a significant enhancement." Our design could be modified to create immersive experiences in theaters.
The researchers explain how they combined two different light-field technology to create large-scale 3D images that have a very low diffraction limit in The Optical Society journal Optics Letters. Autostereoscopic means the display produces multiple 3D images that can be viewed from different angles.
Lee said that he had developed a method to perform all display processes optically, without using any digital processing. This compensates for each technology's limitations to enable the creation of high-resolution 3D images onto a large screen.
Combining technologies
Light-field displays reproduce light that has been reflected from objects in a way that matches the actual visible position. Autostereoscopic light-field displays require large amounts of information to process because they produce images that are different for different viewing angles. Because of this demand, there is a compromise between the resolution and size of the displayed images. The display hardware becomes overwhelmed by the volume of information.
The new display automatically maps the rays from a microlens array to create an optical pickup that transforms the object display volume created by the multifocal monitor into integral imaging projections. Through a projection lens, the transformed information can be magnified to enlarge it on a large screen. The object display volume can be reconstructed after the projection. This is done by passing through another lens array in a manner similar to the integral imaging system. Credit: Byoungho, Seoul National University
Researchers devised a new optical system that combines integral imaging with a multifocal display to overcome this limitation. A multifocal display is capable of producing high-quality volumetric images, but it can be difficult to implement on large-screen systems. Integral imaging, on the other hand is more effective at enlarging images.
The new design uses the multifocal display to generate a high-resolution, volumetric 3D scene, while integral imaging technology magnifies it for larger viewing on large screens. All information is converted optically between integral imaging and multifocal displays without any digital processing.
Lee stated that the method is more than simply combining two existing methods. It achieves an ultrahigh-definition volumetric-light-field display with almost diffraction limited resolution. We also discovered a way to efficiently resolve the problem of enlarging volumetric scenes and overcome information loss problems that can affect integral imaging.
High-resolution, large 3D images
The researchers confirmed the reconstruction of a volumetric image by qualitatively verifying the resolution of the prototype. The prototype was able to synthesize a volumetric picture of 21.4 cm by 21.4 cm by 32 cm. This is equivalent to 28.6 megapixels and 36 times more resolution than the original.
Lee stated that "our approach is very efficient in processing information, which allows a low computing costs as well as simple and high-quality real-time system configuration." The optical design can be integrated seamlessly with other techniques in existing light-field displays.
Researchers are currently optimizing the optics and reducing the complexity of the multifocal displays to make the projector smaller. The system is a combination of two technologies. This will allow for improved performance.
Learn more about nanoscale 3D printing for high-resolution light field prints
Further information: Youngjin Jo and al, Ultrahigh definition volumetric light field projection. Optics Letters (2021). Information for Journal: Optics Letters Youngjin Jo et al., Ultrahigh-definition Volumetric Light Field Projection, (2021). DOI: 10.1364/OL.431156
