Screen shows 3D images without power

A fresh generation of energy-efficient 3D displays could be on the horizon which will not need power to display an image. The optically rewritable liquid crystal displays (ORWLCD) will be of particular benefit to applications where static images are displayed for some time before changing, such as basic digital signage deployments.

Researchers from the Hong Kong University of Science and Technology drew up the concept, the 3D aspect of which works by dividing the image in three parts with different optical axis.

The ORWLCD screen differs from its LCD counterpart mainly in that it lacks the electrodes that untwist the liquid crystal molecules and manipulate the way that light interacts with them. Instead, the image is created using a flash of light (the only part of the process which requires power), which passes through the polarised glass and aligns the liquid crystal molecules.

To generate the 3D image, a quarter-wave plate is placed on the top of the ORWLCD to modify the emerging light from different domains of the image in a different manner. Polaroid glasses, the researchers say, can be used to visualise the 3D image.

The researchers explained, in the journal Optics Letters: “The 3D image can be refreshed, on the 3D-ORWLCD, in one-step with proper ORWLCD printer and image processing, and therefore, with easy image refreshing and good image quality, such displays can be applied for many applications.”

So far, the prototypes has only been able to display grayscale images at a low refresh rate that is unsuitable for video, but researchers are confident colour and video will be accommodated in their devices given further development.