Letter

A multi-directional backlight for a wide-angle, glasses-free three-dimensional display

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Abstract

Multiview three-dimensional (3D) displays can project the correct perspectives of a 3D image in many spatial directions simultaneously1,2,3,4. They provide a 3D stereoscopic experience to many viewers at the same time with full motion parallax and do not require special glasses or eye tracking. None of the leading multiview 3D solutions is particularly well suited to mobile devices (watches, mobile phones or tablets), which require the combination of a thin, portable form factor, a high spatial resolution and a wide full-parallax view zone (for short viewing distance from potentially steep angles). Here we introduce a multi-directional diffractive backlight technology that permits the rendering of high-resolution, full-parallax 3D images in a very wide view zone (up to 180 degrees in principle) at an observation distance of up to a metre. The key to our design is a guided-wave illumination technique based on light-emitting diodes that produces wide-angle multiview images in colour from a thin planar transparent lightguide. Pixels associated with different views or colours are spatially multiplexed and can be independently addressed and modulated at video rate using an external shutter plane. To illustrate the capabilities of this technology, we use simple ink masks or a high-resolution commercial liquid-crystal display unit to demonstrate passive and active (30 frames per second) modulation of a 64-view backlight, producing 3D images with a spatial resolution of 88 pixels per inch and full-motion parallax in an unprecedented view zone of 90 degrees. We also present several transparent hand-held prototypes showing animated sequences of up to six different 200-view images at a resolution of 127 pixels per inch.

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References

  1. 1.

    Autostereoscopic 3D displays. Computer 38, 31–36 (2005)

  2. 2.

    Three-Dimensional Imaging Techniques (Atara Press, 2011)

  3. 3.

    , , & Layered 3D: tomographic image synthesis for attenuation-based light field and high dynamic range displays. ACM Trans. Graph. 30 (95). 1–12 (2011)

  4. 4.

    , , & Tensor displays: compressive light field synthesis using multilayer displays with directional backlighting. ACM Trans. Graph. (Proc. SIGGRAPH) 31, 1–11 (2012)

  5. 5.

    & Light field rendering. In Proc. 23rd Ann. Conf. on Computer Graphics And Interactive Techniques (SIGGRAPH '96) 31–42 (ACM, New York, 1996)

  6. 6.

    et al. Holographic three-dimensional telepresence using large-area photorefractive polymer. Nature 468, 80–83 (2010)

  7. 7.

    et al. 3D image quality of 200-inch glasses-free 3D display system. Proc. SPIE 8288, (2012)

  8. 8.

    & Characterization and optimization of 3D-LCD module design. Proc. SPIE 3012, 179–186 (1997)

  9. 9.

    & Multi-projection of lenticular displays to construct a 256-view super multi-view display. Opt. Express 18, 8824–8835 (2010)

  10. 10.

    Diffraction-Specific Fringe Computation for Electro-Holography. PhD thesis (MIT, 1994)

  11. 11.

    et al. Partial pixels: a three-dimensional diffractive display architecture. J. Opt. Soc. Am. A 12, 73–83 (1995)

  12. 12.

    , , , & High-efficiency sub-wavelength diffractive element patterned in a high-refractive-index material for 633 nm. Opt. Lett. 23, 552–554 (1998)

  13. 13.

    Optical glass. US patent 8,187. 986 (2012)

  14. 14.

    , , & Spatioangular prefiltering for multiview 3D displays. IEEE Trans. Vis. Comput. Graph. 17, 642–654 (2011)

  15. 15.

    , , & Antialiasing for automultiscopic 3D displays. In Eurographics Symposium on Rendering (2006)

  16. 16.

    Variation and extrema of human interpupillary distance. Proc. SPIE 5291, 36–46 (2004)

  17. 17.

    et al. MEEP: a flexible free-software package for electromagnetic simulations by the FDTD method. Comp. Phys. Commun. 181, 687–702 (2010)

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Acknowledgements

We are grateful to C. Santori for many suggestions on the backlight design, A. Jeans for performing the roll-to-roll imprint jobs, A. Said for generating some of the multiview images shown in Fig. 2, L. Kiyama and W. Mack for the printed circuit board design of the portable prototypes, R. Cobene for his help with packaging, P. Beck for her help in the cleanroom, and B. Culbertson and C. Patel for their support of the project.

Author information

Affiliations

  1. Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, California 94304, USA

    • David Fattal
    • , Zhen Peng
    • , Tho Tran
    • , Sonny Vo
    • , Marco Fiorentino
    • , Jim Brug
    •  & Raymond G. Beausoleil

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Contributions

All authors contributed extensively to the work presented in this paper. D.F. conceived the multi-directional backlight concept. D.F. and J.B. led the technical effort to realize the various prototypes. D.F., Z.P., S.V. and T.T. were responsible for the nanometre-scale fabrication of the backlight. J.B. and M.F. were responsible for the optical design and assembly of the prototypes. M.F. designed the illumination systems and part of the other electronics for the prototypes. R.G.B. supervised and coordinated the project. All authors contributed to the data analysis. D.F. and R.G.B. prepared the manuscript with input from J.B., M.F. and Z.P.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to David Fattal.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Text and Data, Supplementary Figures 1-7 and Supplementary References.

Videos

  1. 1.

    Portable transparent backlights.

    This video highlights the main features of our multi-directional backlight technology: large view angle, spatial multiplexing of colors, compact form factor, portability and transparency.

  2. 2.

    Backlight fabrication by roll-to-roll imprint.

    This video briefly explains the roll-to-roll imprint process that can be used for the mass-production of static 3D backlight patterns, and compares the result with a prototype made by electron beam lithography.

  3. 3.

    Static 3D images from a 6 inch backlight.

    This video shows various static 3D images in color, created by aligning a printed ink mask on top of a 6 inch diameter backlight. Note the large amount of motion parallax.

  4. 4.

    Active LCD modulation of backlight.

    This video shows the active modulation of an inch-size backlight by a commercial LCD shutter device. Only a fraction of the LCD is functional due to thinning of the top cover glass, yet video-rate modulation of 14 views is demonstrated.