Cellophane Turns LCDs 3D

From Technology Research News August 26, 2003

Sometimes ordinary items have more to them than meets the eye. For the past couple of decades research teams have worked to make various types of three-dimensional displays; most methods include fairly complicated hardware. A University of Toronto researcher has taken a different tack. As it turns out, a trip to the kitchen and a pair of crossed polarizer glasses can turn an ordinary laptop screen into a 3D display. The method could lead to extremely low-cost three-dimensional applications for scientific and medical imaging, and for games. The researcher's tests verified that a sheet of ordinary cellophane possesses the properties necessary to rotate the direction of white light polarization 90 degrees. It is possible to rotate the polarization of the light coming from one half of a laptop screen by simply covering that side with cellophane. Showing two copies of an image that are polarized differently through a pair of glasses that blocks light polarized in different directions for each eye allows a viewer to see a different copy of the image with each eye. This creates the illusion of three dimensions because the human brain judges distances based on the differences in the views seen by each eye. The colorless, 25 micron-thick cellophane was better than the commercial half-wave plates usually used for the job and 3,500 times less expensive, according to the researcher. The work appeared in the August 2003 issue of the Review of Scientific Instruments.