August 20, 2012

South Korean Team Develops New Method For Glasses-Free 3D

Michael Harper for - Your Universe Online

For years and years, even in the early days of cinema and television, engineers and researchers have tried to craft a way to add the illusion of depth to projected images. We´ve long relied on glasses in order to achieve this 3D effect, and while the glasses we use now are a far cry away from the paper blue-and-red lenses we once wore, many are still attempting to create a lens free solution.

Now, an optics research team from South Korea has developed a system where not only is glasses-free 3D possible, it´s could also be available for commercial theaters, bringing the depth and wonder to audiences everywhere.

What´s more, this new technique can also deliver a 3D experience more efficiently and at a lower cost than existing 3D technologies.

The team describes their method in the Optical Society´s journal Optics Express.

“There has been much progress in the last 10 years in improving the viewers´ experience with 3-D,” writes the team´s lead researcher Byoungho Lee, a professor at the School of Electrical Engineering, Seoul National University in South Korea

“We want to take it to the next step with a method that, if validated by further research, might constitute a simple, compact, and cost-effective approach to producing widely available 3-D cinema, while also eliminating the need for wearing polarizing glasses.”

The key to any 3D technology lies in how polarization is handled. Polarization describes the way light waves vibrate and bounce around an object. When the sun shines, for example, the light waves vibrate in many different directions. In today´s modern 3D technology, movie theaters use linearly or circularly polarized light. In this method, two projectors display similar images onto a screen, slightly offset from one another. When the viewer puts on the polarized glasses, each eye can perceive each of the offset images, adding the illusion of depth to the projected images.

In the new method created by the South Korean team, a “slat” effect is achieved by using different polarizers which stop the passage of light after it´s already been reflected off the screen.

Then, to make sure they block just the right amount of light from the projection, the South Korean researchers add a specialized coating to the screen, known as quarter-wave retarding film. This film works by changing the polarization state of the projected light, ensuring that it can no longer pass through the other polarizers.

As some light passes through the polarizers and some light passes between them, an offset effect is created. This offset effect is perceived in our brains as 3 dimensional, allowing us to immerse ourselves in a three-dimensional experience. This new method allows viewers to experience this illusion all without the need of glasses.

The South Korean team has been able to effectively display these results on 2 types of 3D displays. First, this method can be used on a parallax barrier method display, which works by placing devices in front of the screen to separate the images and allow each eye to view a different , slightly offset image.

This new method can also work with the integral imaging method of displaying 3D images, which uses a two-dimensional set of tiny lenses to create the 3D effect.

“Our results confirm the feasibility of this approach, and we believe that this proposed method may be useful for developing the next generation of a glasses-free projection-type 3-D display for commercial theaters,” says Lee.

For their next experiment, the team hopes to expand the functionality of this new method and apply it to over single-projector and frontal methods of 3D displays. Though this research is exciting for 3D fans, it may be several years before it ever makes it to your local cinema.