How Glasses-Free 3D Works

Posted on: [techpp.com]

There are multiple ways for 3D to be viewed without the need for glasses. Tom’s Guide discovered that Nintendo 3DS uses a parallax LCD barrier made by Sharp. As WikiPedia points out:

a parallax is an apparent displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines

The image below should make more sense. If the beginnig of 3D has been marked by the concept of stereoscopy, the 3D technology without glasses is scientifically called autostereoscopy. The above example with the parallax barrier used in the Nintendo 3DS also depicts how autostereoscopy works. Yet again, the glasses-less 3D technology isn’t something new and is actually 26 years old, being invented in 1985 by Reinhard Boerner at the Heinrich Hertz Institute from Berlin.

Lenticular Technology

While parallax barrier seems to be the most efficient way to make 3D without glasses (if it weren’t, Nintendo haven’t sold more than 4 million units) there are other ways for 3D to be viewed without glasses. Gabriel Lipmann is the inventor credited with the principle of integral photography; a process that combines 2 arrays of lenslets to capture a 3-D scene. The image below should tell you a thousand words… Do you notice the difference? Instead of the parallax barrier there are some concave lenses. The lenses have been slanted so that they could be in “harmony” with the substratal pixel grid. The lenticular technology has an increased level of brigthness than the parallax barrier and it also has wider viewing angles.

Integral Photography and Imaging

Integral imaging basically represents the improvement of lenticular technology but the processes that it has to go through to deliver a glasses-less 3D experience are pretty expensive, this being, so far, the single reason why it isn’t being widely adopted. The first complete method for integral imaging was the Integral Photography:

the lens array is used to both record and play back a composite three-dimensional image. When an integral lens array sheet is brought into contact with a photographic emulsion at its focal plane, and an exposure is made of an illuminated object that is placed close to the lens side of the sheet, each individual lens (or pin-hole) will record its own unique micro-image of the object

Nintendo 3DS – The First 3D Gaming Console Without Glasses

We previously also wrote about Nintedo’s famous CEO and how rich this company’s history actually is. TheNintendo 3DS gaming console is a device that wants to be the forerunner of what the next step in 3D technology could be: no glasses. The glasses-free 3D gaming device has been released at the end of February, in Japan. These are the main ways to make 3D experience become free of glasses. However, there are also other methods, not as efficient but still in testing:

• holography
• volumetric display
• Pulfrich effect
• head tracking 3D technology
• master image 3D