Large real-time holographic displays with full color are feasible with SeeReal's new approach to holography and today's
technology. The display provides the information about the 3D scene in a viewing window at each observer eye. A
tracking system always locates the viewing windows at the observer eyes. This combination of diffractive and refractive
optics leads to a significant reduction of required display resolution and computation effort and enables holographic
displays for wide-spread consumer applications. We tested our approach with two 20 inch prototypes that use two
alternatives to achieve full color. One prototype uses color filters and interlaced holograms to generate the colors
simultaneously. The other prototype generates the colors sequentially. In this paper we review our technology briefly,
explain the two alternatives to full color and discuss the next steps toward a consumer product.
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.
3D displays comprise stereoscopic displays and holographic displays. Eye convergence and accommodation are
important depth cues for human vision. Stereoscopic displays provide only convergence information whereas
holographic displays also provide accommodation information. Due to the inherently better 3D quality we consider
holographic displays as the preferred alternative to stereoscopic displays. Our new approach to holographic displays
omits unnecessary wavefront information and significantly reduces the requirements on the resolution of the spatial light
modulator and the computation effort compared to conventional holographic displays. We verified our concept with
holographic display prototypes and measurements. SeeReal's approach makes holographic displays feasible as a
consumer product for mass-market applications.
Dependence on sub-micron pixel pitch and super-computing have prohibited practical solutions for large size
holographic displays until recently. SeeReal Technologies has developed a new approach to holographic displays
significantly reducing these requirements. This concept is applicable to large "direct view" holographic displays as well
as to projection designs.
Principles, advantages and selected solutions for holographic projection systems will be explained. Based on results from
practical prototypes, advantageous new features, as large size full-color real-time holographic 3D scenes generated at
high frame rates on micro displays with state of the art resolution will be presented.
This paper illustrates one of the various capabilities of static diffractive optical elements (DOE) beneficial to realtime
holographic displays. Custom kinoform-type DOE can be used as elements for illumination of the spatial
light modulator, i.e. the display where the video hologram is encoded. For an RGB application of diffractive
optical elements, particular issues concerning the inherent wavelength-dependence have to be addressed. Multiorder
DOE offer a way to compensate for chromatic as well as monochromatic aberrations. We will discuss
concepts and performance of multi-order DOE, show their application in holographic displays, describe issues of
fabrication and replication, and give experimental results of the multi-order DOE performance.
Holography is generally accepted as the ultimate approach to display three-dimensional scenes or objects. Principally,
the reconstruction of an object from a perfect hologram would appear indistinguishable from viewing the corresponding
real-world object. Up to now two main obstacles have prevented large-screen Computer-Generated Holograms (CGH)
from achieving a satisfactory laboratory prototype not to mention a marketable one. The reason is a small cell pitch CGH
resulting in a huge number of hologram cells and a very high computational load for encoding the CGH. These
seemingly inevitable technological hurdles for a long time have not been cleared limiting the use of holography to
special applications, such as optical filtering, interference, beam forming, digital holography for capturing the 3-D shape
of objects, and others. SeeReal Technologies has developed a new approach for real-time capable CGH using the socalled
Tracked Viewing Windows technology to overcome these problems. The paper will show that today's state of the
art reconfigurable Spatial Light Modulators (SLM), especially today's feasible LCD panels are suited for reconstructing
large 3-D scenes which can be observed from large viewing angles. For this to achieve the original holographic concept
of containing information from the entire scene in each part of the CGH has been abandoned. This substantially reduces
the hologram resolution and thus the computational load by several orders of magnitude making thus real-time
computation possible. A monochrome real-time prototype measuring 20 inches has been built and demonstrated at last
year's SID conference and exhibition 2007 and at several other events.
Display technology has made big advances in last years. Displays are flat, offer high resolution, are bright, fast and almost free of flicker. Apart from new technologies that make displays still more
affordable the major direction of development turns to applications, especially TV. In this consolidation process new features are sought. Still lacking is the 3D display capability most obvious
compared to viewing real-world scenes.
In the last decades a lot of new 3D technologies have been proposed, developed and only few have reached the commercial market. A breakthrough into the mass market has been prevented for technical as well as commercial reasons. Most natural viewing is provided by holography. Unfortunately, even the technical challenges are so demanding that the 3D research community turned to the stereoscopic technology known for more than a century. Many technologies have been
proposed and the shutter technique has already matured to a commercial product. But the mass market requires 3D viewing without using additional viewing aids. Currently, these Autostereoscopic 3D Displays still cannot meet the quality standard and comfort of today's 2D displays. In our opinion 3D displays should first of all match all of today's 2D demands and additionally be capable of 3D displaying.
For tracking based autostereoscopic displays an eye position detection system is needed. We built a real-time image processing unit that not only achieves a high level of detection reliability but also is cost effective and can be integrated in a display housing. The device is able to autonomously find the eyes of the user and track them without the need of any markers or special lighting. The system consists of a stereo camera and proprietary DSP-based hardware and software. We describe determination of parameters of the optical system and correction of image distortion as well as algorithmic details. Performance results and future developments are discussed.
A tracking based autostereoscopic 3D Display (D4D) has been developed at Dresden University of Technology. It employs a Flat Panel Display (FPD) and is designed for single users. Both stereoscopic half images are displayed simultaneously in alternating FPD columns. The separation of both half images to the viewer's eyes is accomplished using a prism mask in front of the FPD. The tracking is performed in two ways. Firstly, the separation mask is shifted mechanically against the stereoscopic image according to the viewer's position. Secondly, the stereoscopic image is shifted electronically. The D4D is extremely flat. Regular flat panel displays or even notebooks can be made autostereoscopic using the D4D technology Add-Ons. The development of the D4D has been funded by the Saxonian State Ministry of Economy and Labor.
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