With SeeReal’s extensive background in development and manufacture of Stereoscopic 3D (S3D) displays, it became obvious to the SeeReal team a long time ago that S3D inherently can never provide a comfortable long-term viewing experience of natural looking 3D scenes with properly scaled depth. S3D’s “2x 2D views” principle (one 2D view for the left eye and one for the right eye) is not capable delivering all visual depth cues to the human sensory system. This applies to all Stereo 3D solutions – no matter if with Stereo glasses or without (Auto-Stereo). Also, the resulting requirement for depth-compressed 3D of S3D systems prohibits proper scale of 3D images which is either boring for consumers or prohibitive to professionals – just imagine a surgeon looking at an organ or an engineer working on a CAD design generated with improper depth. But even depth-compressed S3D with missing 3D cues generates eye fatigue or discomfort to a significant part of the population.
Overcoming the super-resolution display requirement of “classic holography”
A long time ago, first holograms were made using high resolution analog film, easily with up to 5000 lines per millimeter resolution. Since such film is capable of generating very fine structures, diffraction angles can be very large. This translates into large viewing angles onto these “classic holograms”. Accordingly, 3D reconstructions from analog holograms are visible in a large area in front of the hologram. But transferring this principle to digital display technology would mean generation of extremely small displays pixels – at an extreme quantity. Even if this was possible (and scalable) computation requirements scale to PetaFLOP range for a decently sized display presenting holographic reconstructions with high H3D resolution and large 3D depth. Proper coherent illumination of such system is still another challenge.
Eliminating the need for super-computation resources of large high-resolution 3D holograms
As explained above, SeeReal limits the holographic information to what observers of a H3D display, or in fact of any real life environment, can see at a given point in time and space. By limiting the information to eye boxes or Viewing Windows, one also limits the area on the physical display, the hologram, required to encode information for individual portions of the 3D scene. One may say, SeeReal discretizes the hologram. In fact, each 3D scene point can be encoded in a very small individual hologram which are then super-positioned to generate the total 3D scene. SeeReal established the term “Sub-holograms” for these hologram fractions.
Simplifying the light source coherence requirements for large holographic 3D reconstructions
Breaking down a 3D scene and corresponding hologram into small fractions, which SeeReal many years ago introduced as Sub-holograms, greatly simplifies the illumination requirements. In “classic holography” each portion of the hologram (or H3D display) must be in sync, because all portions contribute to each portion of the 3D reconstruction; light from all physical display pixels interferes. This requires laser light sources with a coherence length at least as large as the physical display size, which calls for quite expensive lasers.