AR Capabilities

TruLife has developed the unique design tools required to input images into a curved waveguide of any radius, ensuring that the light inside the waveguide has a continuous wavefront and that pupil replication is achieved without split images. We can work with all types of input techniques, whether diffractive, refractive, or reflective as well as most projector formats to enable almost any waveguide design to be curved rather than planar.

Surface relief

We can work with surface relief designs – we can either model how the grating structure needs to be changed to work on a curve- this structure would be pre-compensated for manufacture in your current method on flat – to be laminated onto the cylinder radius of your choice – or we could design a volume HOE that would match your specification for a curved format.

We have also pioneered a new input geometry, enabling a small input pupil (2mm- 4mm) but only requiring pupil replication horizontally, thereby removing the need for complex turn gratings while still supporting an eye-box of 10mm (horizontal) by 8 mm (vertical)- picture below shows Jade Bird projectors with a very small form factor – these are compatible with our Curved Waveguide as shown by the working prototype illustrated.

Less Pivot Weight

A curved waveguide enables the projector to be moved back, reducing the pivot-weight onto the nose.

Encapsulation in RX prescription lenses – TruLife have developed an encapsulation method that allows the curved waveguide and HOE to be inserted into the centre of industry standard RX prescription lenses, enabling Augmented Reality to be supplied utilising the existing highly well established and experienced ophthalmic supply chain.

Our encapsulation takes advantage of the aspect ratio of glasses with the significant advantage that a curved waveguide can fit within spectacle lenses in a slimmer format than a flat waveguide, reducing thickness and offering a more natural curved form factor.

Privacy

The curved waveguide also solves a privacy problem intrinsic to flat waveguides. AR images going through flat waveguides couple out towards the outside world without distortion which can be seen and read by other people. The curved waveguide solves this privacy problem by applying aberrations to any outside- image.

The image below shows a picture taken very close to the eye of someone reading content on our curved waveguide glasses.

We show that the content was a very large “30” – far larger than any text you would read – illustrating that the curved waveguide is much more confidential than a planar waveguide which is like a mirror – the image to the eye is identical to the image away from the eye.

Eye glow is lower thanks to our hybrid eye box design meaning fewer places of outcoupling the light. Our eye glow is more of a slit of light rather than a large rectangle covering the eye.

Brightness

Because we only replicate in one direction, the light source spreads out less, leading to improved brightness – easily exceeding 1,000 Nits.

For RGB output we only need one waveguide, and the gratings are in one layer – alternative systems can require 3 waveguides and 3 layers and a turn grating adding cost, complexity and wasted space (non-image area) on the lens.

Eye box located where you want it

As we do not employ a turn grating the eye box can be placed centrally whereas in systems with a turn grating, the turn grating wastes area adding to the weight of the high-density glass lens.