Autostereoscopy

Autostereoscopy ( from the Greek auto = self - stereo = fixed, rigid - skopein = see) refers to methods for displaying three-dimensional images for a sense of depth through stereoscopic vision. It requires no tools for this technique right before the eyes, such as head - mounted displays or 3D glasses. Typical methods for the realization of autostereoscopic displays are usually parallax and lenticular, but also volume displays and holography are included in this definition.

An autostereoscopic 3D display

Under an autostereoscopic 3D display refers to the display of autostereoscopic images on a screen or a projection.

Technology

To achieve a three-dimensional impression, two images are simultaneously displayed in the autostereoscopic display, said means Parallaxbarrieren so inclined stripe masks or lenticular, the individual pixels of light is deflected in different directions in front of the screen, and reaches each eye a different image. By dividing the screen surface on two nested sub-images, the horizontal resolution per eye halved.

A problem of autostereoscopic displays is like stereo images in that the lens of the eye does not need to be focused on the perceived depth of an object represented, but on the removal of the display, ie the difference between convergence and accommodation of the eye. This can lead to irritation and without training some people causes the consideration of such 3D images particularly over longer time eyestrain and headaches.

Single View display

In a single- view display the depth effect is caused by the fact that the screen displays two separate images. In this case, the user's head must be located on a very restricted optimal position ( "sweet spot" ) to get a proper stereo image. Some displays can compensate for limited lateral head movements by the user is tracked by video camera (so-called eye tracking or head tracking ) and the representation is changed so that the " distribution" of the images true to his eyes again. Since the screen can always respond optimally to only one pair of eyes, this autostereoscopic display and single -user display. However, there is also a variation of this technique, a compromise for the best view of all calculated at several viewers. This average is then not as optimal as for a single person. Kopf-und/oder eye tracking is not used in any single- view display.

Multi-View Display

In a multi -view display more than two sub-images are shown in use are so far 5-9, some were also 24 and 64 tries, which increases the lateral movement and the image quality ( horizontal resolution) decreases accordingly. They work similar to lenticular images with these systems, multiple users can see the 3D image. It is also possible, a little to objects " look around ". The result is a hologram -like image impression, but for spatially realistic looking objects is a " volumetric 3D display " better suited ( first patented in 1941 by Scottish television pioneer JLBaird ).

History

The Parallaxbarrierenprinzip with inclined screens in 1903 by Englishman FE Ives patented as " Parallax Stereogram ". The lenticular technique was first proposed in 1908 by M. Gabriel Lippmann. Instead opaque Parallaxbarrieren to use, he explained the idea to use a series of lenses.

An early application of Parallaxbarrierentechnik was the projection to " wire mesh screens ," which was first held in Moscow in 1930. Such a mechanical image separating system has already been postulated by Estanawe 1906, who proposed a fine grid of metal slats as a canvas. In the projection, the viewer must be placed very precisely in front of the screen, otherwise can not see the specific image for each of them the eyes. The system was improved by Noaillon who ordered the grid to the viewer inclined and who are now radial grid strips easily reciprocated. Further developed the system of Ivanov, who used instead of a mechanical parallel grid 30,000 very fine copper wires as canvas was. The elaborate process did not achieve mass production. Only one cinema was rebuilt for the system, the Moskva in Moscow. Few films have been shown in this procedure.

Various autostereoscopic techniques are around 2001 for LCDs on the market and were mainly in Jena since the mid- 1990s ( More summaries solution, 4D - Vision GmbH, today VisuMotion GmbH), Dresden ( Two views solution, Dresden 3D GmbH, today SeeReal Technologies ), Berlin ( Two views solution, Heinrich-Hertz - Institut GmbH, today Fraunhofer HHI) and Kiel (Still 30,000 views solution RealEyes GmbH) developed. Chance laptops and TFT monitors with " Parallax Barrier " 3D display have been offered, for example by Sanyo.

The technique when Nintendo 3DS is based, for example on the Parallaxbarrierenprinzip, on the other hand with the Fujifilm Finepix Real 3D camera a lenticular display with lenticular is integrated.