New technology lays the groundwork for large-scale, high-resolution 3D displays

Researchers have developed a prototype screen that uses projection to create large-scale 3D images with ultra-high definition. The new approach overcomes the limitations of light field projection, which can create natural-looking 3D images that do not require special 3D glasses for viewing.

“Our optical design could replace 2D flat screens with 3D images for digital signage, entertainment, education and other applications where 3D images offer significant improvement,” said the team leader. Byoungho Lee Research Fellow at Seoul National University in Korea. “Our design could also be changed to provide immersive experiences in movie theaters, for example.”

In the journal The Optical Society (OSA) Optical letters, the researchers describe how they combine two different light-field display technologies to project large-scale 3D images with resolution almost limited by diffraction. The new display is autostereoscopic, which means it produces different 3D images so the image can be viewed from different angles.

“We have developed a way to perform all display processes optically without any digital processing,” said Lee. “This compensates for the limitations of each display technology to enable the creation of high-resolution 3D images on a large screen.”

Combine technologies

Brightfield displays work by reproducing light reflected from an object in a way that matches the actual visible position. Since autostereoscopic bright field displays produce different images for different viewing angles, they require a huge amount of information to be processed. This demand creates a trade-off between the resolution and the size of the displayed image, as the screen hardware is overwhelmed with the amount of information required.

To overcome this limitation, the researchers designed a new optical configuration that combines a multifocal display with full imaging. Typically, a multifocal display can generate a high quality volumetric image, but it is technically difficult to implement on a large screen system. On the other hand, full-length imaging is better for enlarging images.

In the new design, the multifocal display generates a high-resolution, or volumetric, 3D scene, while the built-in imaging technology enlarges it for viewing on a large screen. The conversion of information between multifocal display and full imaging is done entirely optically without any digital processing.

“Our method goes beyond simply combining two existing methods to achieve an ultra-high definition volumetric light-field display with near-diffraction-limited resolution,” said Lee. “We have also found a way to effectively solve the difficulty of enlarging a volumetric scene and overcome information loss issues that tend to affect full-length imagery.”

Large, high-resolution 3D images

After checking the resolution of their prototype system, the researchers qualitatively confirmed that a volumetric image had been reconstructed. Tests have shown that the prototype can synthesize an 8.5 ” x 8.5 ” x 12 ” volumetric image, which is equivalent to 28.6 megapixels and 36 times the resolution of the original image.

“Our approach is very efficient at processing information, resulting in low IT cost as well as simple, high-quality, real-time system configuration,” said Lee. “The optical design can also be seamlessly integrated with various techniques used in existing brightfield displays.”

Researchers are now working to optimize optics and further reduce the complexity of the multifocal display to make the projector more compact. They note that because the system is a fusion of two different technologies, the performance of their proposed system is likely to improve as each technology develops.