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Method Of Increasing Viewzone For Acoustic Waveguide Displays

ID: 2017-067 A way of increasing the viewzone of waveguide displays.

ID: 2017-067
Principal Investigator: Daniel Smalley

Previous leaky mode near eye displays have a small effective view-zone because the angle of view is dramatically reduced when rotated by the final output grating.

This technology provides a way to increase the viewzone of waveguide displays by using the combination of two gratings, to both create modes and rotate the angle of leaky mode light to provide an increase in view zone without resorting to increasing the display space bandwidth product.

Transparent, holographic flatscreen and near-eye displays using leaky mode light can have small resulting viewzones when light is rotated by an output grating on the front or back face of the display (instead of the edge of the display). The viewzone may be small, but it travels across the entirety of the aperture as the surface acoustic wave travels across the aperture. If multiple modes were used, each at a different angle, each traveling across the entire aperture, each entering the eye at a different time, it would be possible to build a large aggregate viewzone. This invention uses multiple modes of the leaky mode output to build up a wide viewzone. The figures on the right will illustrate the setup. Leaky mode light exits from beneath a moving surface acoustic wave. The light then encounters a grating which breaks the beam up into multiple orders, each with a different angle. The light then propagates over a distance (d3) before encountering a second grating (grating 2) which rotates the light so that it exits the face of the display. The combination first grating period, second grating period, and propagation distances can be used to create virtual point viewzones (called 'image regions' in the first figure on the right) that are separate, that abut, or that overlap each other to create a large aggregate viewzone (large image region) from the perspective of the viewer.

The invention could include more than two gratings to perform the functions of splitting and rotating. This function could be mirrored so that the gratings were used by leaky mode light from left-going or right going SAWs, or left-going or right-going waveguide light. Positive and negative diffracted modes. The splitting and rotating functions could be distributed in any proportion between gratings.

About the Market:
This technology will be used in improving characteristics of near-eye holographic displays and flat screen holographic displays. The holographic displays global market is expected to reach over $3.5 billion in annual sales by 2020, and $1.82 bllion by 2021 in Americas (driven mainly by growth of commercial and medical industry).

For more information, contact Dave Brown (801-422-4866)

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