3D Display Goes Deeper

By Roland Piquepaille

When it comes to three-dimensional displays, there are usually compromises. Some methods have narrow viewpoints that require a user to view the image from directly in front of a screen. Some methods require that the user look through special glasses. Other methods don't provide a lot of depth.

Researchers from Seoul National University in Korea have found a way to deepen one type of three-dimensional display method -- integral imaging -- that has historically suffered from relatively shallow depth, but does not require users to wear glasses.

The method makes images appear at three distinct depths by controlling the polarization and direction of the light rays that the display generates. The researchers' prototype display contains a polarizer and sliding slit mask, a calcite crystal, and an array of lenses.

Here is a diagram of the proposed InIm system. (Image: Copyright 2003 Optical Society of America)

The method could eventually be used to make three-dimensional billboards and three-dimensional television.

The research paper, "Integral imaging with multiple image planes using a uniaxial crystal plate," was published by Optics Express. Here is the abstract.

Integral imaging has been attracting much attention recently for its several advantages such as full parallax, continuous view-points, and real-time full-color operation. However, the thickness of the displayed three-dimensional image is limited to relatively small value due to the degradation of the image resolution. In this paper, we propose a method to provide observers with enhanced perception of the depth without severe resolution degradation by the use of the birefringence of a uniaxial crystal plate. The proposed integral imaging system can display images integrated around three central depth planes by dynamically altering the polarization and controlling both elemental images and dynamic slit array mask accordingly. We explain the principle of the proposed method and verify it experimentally.

If you want to read the full research paper -- providing you have a degree in optics -- you can get it in PDF format (1,479 KB).

Sources: Technology Research News, September 25, 2003; Optics Express, Vol. 11, No. 16, August 11, 2003