March 22, 2013
HP Labs has developed a new kind of three-dimensional display that can play hologram-like videos without requiring moving parts or glasses. Videos hover above the screen as viewers walk around them and experience an image or video from up to 200 viewpoints, essentially simulating the experience of moving around an actual physical object. The LCD-based approach could be used by phones and tablets to produce holograms.
“The screen is made by modifying a conventional liquid-crystal display (LCD), the same kind of display found in most phones, laptops, tablets, and televisions. Researchers hope these 3D systems will enable new kinds of user interfaces for portable electronics, gaming, and data visualization,” writes MIT Technology Review.
“The key to making a multiview 3D display is reproducing all the light rays reflecting off an object from every angle and to get a different image to the left and right eye of the viewer,” explains the article. “Some systems for producing multiview 3D images require rapidly spinning mirrors; others use systems of lasers and multiple graphics processors.”
This particular HP display uses nanopatterned grooves, which HP researcher David Fattal calls ‘directional pixels.’ They send light in different directions, requiring no new moving parts.
“Each ‘directional pixel’ has three sets of grooves that direct red, green, and blue light in one particular direction. The number of directional pixels determines the number of viewpoints the display can produce,” details the article. “Light from the pixels then passes through a conventional array of liquid crystal shutters that pass or block the light to make a moving image — just like in a conventional LCD.”
User interfaces this intricate would require a lot of work, Fattal acknowledges, noting that “producing content for the new display requires 200 different images,” writes Technology Review. But he suggests how it might be used in the future. “A 3D interface for a cell phone or laptop might display different windows next to each other, or architects could use a tablet to show a 3D model to a customer, instead of building a physical model. Or you might use a smart watch to view Google Maps in 3D.”
David Krum, co-director of USC’s Mixed Reality Lab, notes that many computer scientists are presently working on developing content for 3D systems. “Part of the challenge, he says, is understanding human perception and which light rays can be left out while still creating the perception of a 3D image for the viewer. Without addressing this, mobile 3D will create big bandwidth and data-storage burdens, he says.”