How does it work?

Three-dimensionality is a sensation produced by our brain, based on different information feeds:
- Disparity between the two slightly offset images seen by our eyes,
- Eye vergence muscular effort,
- Perspective and relative size of objects,
- Shadows and reflections,
- Occlusion effects and relative displacement of objects.

Binocular vision is of course predominant to perceive three-dimensionality. Therefore, classical 3D display processes use two offset views of a scene, called stereo pair. 19th century stereoscopes combined two images of a stereo pair laid side by side, whereas present 3D movies alternately project left and right images, while special glasses discriminate which image will be seen by each eye.

Alioscopy 3D displays are auto-stereoscopic because the three-dimensional effect is immediate and doesn't rely on special eyewear. Content however is special. Instead of assembling one left and one right image, it actually includes 8 images forming 7 successive stereo pairs. These 8 views are multiplexed into one single Alioscopy image, using a proprietary algorithm.

Parts of the following image appear to be blurred on your computer screen. If you were watching the original HD image full screen on an Alioscopy 3D displays, this blur would convert into a staggering 3D effect, and the image would be crisp everywhere. The right wheel of the front airplane would show on the display plane itself, but the tip of its wing would pop-out 40 cm outside of a 42" display, whereas the plane flying in the back would appear to be flying 60 cm behind the screen.

Sample of Alioscopy 8 view image

In order to convert this blur into a three-dimensional feeling and to allow each eye to see a different image, an optical component combining 720 cylindrical micro lenses, called lenticular array, is positioned in a slant on the screen with great accuracy.

Lenticular array covering the LCD panel in a slant

These micro lenses act as tiny magnifying glasses, blowing up a different point of view according to the angle from which they are being looked at. They prevent each eye from seeing more than one point of view at a time among the 8 views mixed in each image. Since both eyes watch the screen from slightly different angles, they both see a different image on-screen, therefore creating a three-dimensional sensation in the brain.

Alioscopy 3D displays are LCD screens, specially chosen for their LCD panel microstructure. Each colored dot, called pixel, is the combination of three sub-pixels of different colors: red, green and blue.

Square pixel on an LCD panel

A Full HD screen aggregates roughly 2 million pixels, assembled in a matrix.

Magnified view of an LCD matrix

The optical components manufactured by Alioscopy have a precision reaching 1/100th of a micron. They are positioned in a slant with the same accuracy requirement on the LCD panel.

Lenticular array positioned in a slant.

Each lens covers exactly 8 sub-pixels, that is 2 pixels 2/3.

Lenses covering 8 sub-pixels.

Each sub-pixel is now used for a different point of view. Rather than having three sub-pixels side by side to form a colored dot, three sub-pixels on three successive lines are now being used. Points of view are labeled in the figure below. Their color components align diagonally with the lenses.

Circular permutation of sub-pixels in a block of 8 rows by 8 columns of pixels.

The position of the spectator determines what he sees on-screen. The point of view magnified by the array of lenses changes every 6.5 cm. Since the eyes are separated by 6.5 cm, each one sees a different image.

Every 6.5 cm, parts of a different point of view is seen through each lens.

The brain therefore reproduces a three-dimensional feeling immediately and naturally.