Spectacle Lens
Encapsulation
TruLife Optics have invented a method of encapsulating an aligned stack of holograms inside an RX ophthalmic curved lens of any desired curvature. We define this as freespace, as there is no waveguide – examples of hologram designs that work this way are VRD, Hybrid Eyebox and Infra Red Eye Tracking. TruLife Optics have developed a curved waveguide, and this waveguide can also be encapsulated in standard ophthalmic RX grade spectacle lenses.
Lens encapsulation – free space
TruLife Optics have invented a method of free space, encapsulating an aligned stack of holograms inside an ophthalmic curved lens of any desired curvature. We define this as as there is no waveguide.
TruLife can supply uncut RX spectacle lenses with the hologram(s) embedded inside it for Augmented Reality customers. TruLife are talking to lens manufacturing partners who want to create RX ophthalmic lenses for Augmented Reality Smart Glasses.
Our lens design is based on the industry standard RX ophthalmic uncut lens – a 75mm diameter injection-moulded/ cast disc with a desired front base curvature, and an arbitrary back surface curvature. We bisect this geometric model via a cylindrical interface, creating two individual solid components. The components are made individually, and can be injection moulded, cast, or milled from existing RX ophthalmic uncut lenses.
One surface of each half is cylindrical – to enable fast lamination of the Holographic Optical Elements (HOEs) from a roll of holographic film. This cylindrical surface can be made to accommodate any base curvature, with the typical range being base 0.5 to base 10 in the ophthalmic industry.
We start with the standard lens shape as used by everyone in the ophthalmic industry and we fabricate the design in two halves – a front and back.
Lens back uncut – front surface a cylinder and back surface a sphere
Lens front uncut – front surface a sphere and back a cylinder
Once the hologram has been encapsulated onto the front cylindrical surface of the back half, the front half is glued on top (cylinder on cylinder) to create an uncut lens.
The outer surfaces are the same as existing ophthalmic lenes. The front surface is spherical profile with the desired base curvature, and the back surface is an arbitrary spherical or aspherical profile. This allows the prescription to be milled onto the back surface of the lens – the same process that is used for typical prescription lenses today.
Once the two lens halves have been combined, encapsulating the HOE, they can be glazed to fit the eyeglass frame – the same process as any normal ophthalmic lens. Therefore, this methodology can be incorporated into ophthalmic supply chain with little disruption or change to their processes.
Two lens halves combined with HOE inside – This is a -2 prescription on 4 Dioptre base curve
Lens encapsulation – waveguided
TruLife Optics have invented a method of encapsulating a cylindrical waveguide in RX spectacle lenses.
We start with the standard lens RX shape as used by everyone in the ophthalmic industry and we fabricate the design in two halves – a front and back.
In our design the inner surface of each half is cylindrical – to enable easy fitting of the waveguide, which is also cylindrical.
The outer surfaces of each of the 2 lens halves are spherical, the same as existing RX ophthalmic lenses – the back (eye-facing) side has an arbitrary curvature, allowing the prescription to be milled into it.
The waveguide is cylindrical will have a holographic optical element laminated to it to take the AR signal into the eye.
Once the lens halves and waveguide have been combined, they can be glazed as any normal lens, meaning this methodology can be incorporated into the current workflow chain. An air gap is created between the cylindrical waveguide and the lenses using spacers. Volume HOEs can be shot RGB on one layer, utilising only 1 waveguide – reducing thickness, weight and complexity (cost).
For more information or an informal discussion please contact: info@trulifeoptics.com
