We present the development and investigation of a holography-based head mounted display (HMD) that uses the proprietary Viewing-Window (VW) technology of SeeReal Technologies to generate a holographic scene. Considering various specification requirements, such as field of view (FOV) and resolution, the development of the HMD system was implemented by means of the optical design software Zemax. A prototypical HMD was set up in the laboratory and several tests were conducted e.g. resolution limit, field of view, and spatial resolution of the holographic reconstruction to investigate the performance. The HMD system reaches a resolution limit of 2.2 cycles/mm at a distance of 1500 mm between observer and image plane. The FOV is 4.1° in the horizontal and 2.3° in the vertical direction. By tuning the focus of a camera it was demonstrated that the holographic reconstruction is spatially resolved in three dimensions. Taking into account all technical specifications and restrictions, the image quality of the HMD was evaluated as good. Using holographic imaging technique has been demonstrated to be suitable to avoid the conflict between accommodation and convergence of the eye and is a promising way in future HMD technology.
SeeReal’s concept of real-time holography is based on Sub-Hologram encoding and tracked Viewing Windows. This solution leads to significant reduction of pixel count and computation effort compared to conventional holography concepts. Since the first presentation of the concept, improved full-color holographic displays were built with dedicated components. The hologram is encoded on a spatial light modulator that is a sandwich of a phase-modulating and an amplitude-modulating liquid-crystal display and that modulates amplitude and phase of light. Further components are based on holographic optical elements for light collimation and focusing which are exposed in photopolymer films. Camera photographs show that only the depth region on which the focus of the camera lens is set is in focus while the other depth regions are out of focus. These photographs demonstrate that the 3D scene is reconstructed in depth and that accommodation of the eye lenses is supported. Hence, the display is a solution to overcome the accommodationconvergence conflict that is inherent for stereoscopic 3D displays. The main components, progress and results of the holographic display with 300 mm x 200 mm active area are described. Furthermore, photographs of holographic reconstructed 3D scenes are shown.
This paper discusses our solution for driving holographic displays with interactive or video content encoded in real-time
by using SeeReal's Sub-Hologram-technology in combination with
off-the-shelf-hardware. Guidelines for correctly
creating complex content including aspects regarding transparency in holograms from both the content side and the
holography side are presented. The conventional approaches for generating computer generated holograms are discussed
in comparison with our solution using Sub-Holograms, to rapidly reduce computation power. Finally the computingplatform
and the specification of our 20 inch direct-view holographic prototype will be presented.
Auto-stereoscopic 3D displays capable of high quality, full-resolution images for multiple users can only be created with
time-sequential systems incorporating eye tracking and a dedicated optical design. The availability of high speed
displays with 120Hz and faster eliminated one of the major hurdles for commercial solutions. Results of alternative
display solutions from SeeReal show the impact of optical design on system performance and product features.
Depending on the manufacturer's capabilities, system complexity can be shifted from optics to SLM with an impact on
viewing angle, number of users and energy efficiency, but also on manufacturing processes. A proprietary solution for
eye tracking from SeeReal demonstrates that the required key features can be achieved and implemented in commercial
systems in a reasonably short time.