Normal 3D displays need special glasses to produce the correct effect, and even then, it's mostly a feel of depth than anything else. You don't get to see the object from a different perspective if you move to a different position in regard to the screen.
Glasses-free panels have the same limitation, in addition to narrowed viewing angles in general. Basically, 3D has hit a sort of limit that needs some creative thinking to surpass.
HP has just revealed something that would be worth calling holographic display technology, if it didn't use a solid, physical medium.
Nonetheless, it does use an LCD panel, albeit a transparent one, so it doesn't quite fit the mold of holograms.
Still, the display renders 3D images through what HP researchers call “directional pixels,” MIT Technology Review reports.
Made from nanopatterned grooves on the display, the pixels send light off in different directions.
Combined with the special way the HP display is cut, each directional pixel gets three sets of grooves that correspond to red, green and blue light. The grooves actually have a second role also, to direct said light.
The reflected light then passes through a standard LCD display and is turned into a moving image.
The video embedded below shows the HP logo. By moving around, a different side of the logo is seen, even though it isn't an actual, physical object with volume.
Obviously, the image quality leaves much to be desired. This is a very early proof of concept system after all. The field of view is of 180 degrees and the video plays at 30 FPS (frames per second).
Images and videos also need to be in a very special format for the display to show them properly. HP researchers said the display needs 200 different images to compose the final, 3D image.