Edinburgh, U.K.: Holoxica has used its expertise in static printed holograms to develop a display that can produce basic moving 3D images that are visible without glasses. The proof-of-concept device combines a holographic screen with an LCD shutter to display monochromatic 3D digits or volumetric shapes around the size of a hand in midair (see the figure). Images can be viewed from a 120° range horizontally and vertically. There’s no “sweet spot” like other 3D displays.
Holoxica’s current demonstrator uses several holograms imprinted on a single screen. Each hologram is exposed in turn by an LCD shutter, controlled electronically, illuminated by a low-power laser diode. Illuminating the holographic images in quick succession can produce a basic moving image. Though the proof-of-concept system has just nine images, Holoxica managing director Javid Kahn says the company is working on scaling up to 25 images to produce a display that could show a full second of 3D video.
Although such multi-exposure holograms have been demonstrated before, full electronic holography based on laser illuminated spatial light modulators is very compute-intensive and limited in size. Kahn hopes that by focusing on displaying basic volumetric shapes or alphanumeric characters in a seven-segment display, Holoxica will be able to bring the advantages of holograms to various applications.
“3D technology today is really twin 2D even with lenticular displays, whereas holographic techniques are inherently 3D. Twin 2D images only work from a head-on position. With holograms, there is a larger field of view,” Kahn points out.
“Research into holographic displays so far has been driven by Star Wars, which is a difficult challenge for researchers to meet,” he adds. “Past research has focussed on high-resolution holograms. We need to forget Star Wars and start at the bottom with the simplest possible display.”
He says the company has received “serious enquiries” for heads-up displays for simple information, such as dials and numerals, and is in tentative talks about producing a 3D animated “speaking head.” He also notes that basic speech can be animated with just 10 different images, similar to what is done in cartoons.