Curved Waveguides Integrated with Eyeglass Lenses
Solution Overview
Problem
Current wearable heads-up displays with planar waveguides appear bulky and lack fashion appeal, failing to integrate effectively with curved eyeglass lenses, which are aesthetically preferred in consumer markets.
Innovation Solution
Integration of planar waveguides within the inner volume of curved eyeglass lenses, with in-couplers and out-couplers strategically positioned to ensure total internal reflection and optimal optical performance, allowing for a seamless and aesthetically pleasing design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If planar waveguides are used in wearable heads-up displays, then optical performance is maintained, but the device appears bulky and lacks fashion appeal
Solution Approach 1:
The patent applies curvature to the waveguide structure by integrating it into curved eyeglass lenses. The waveguide is shaped to match the curvature of the lens (convex on the object side, concave on the eye side), transforming the bulky planar appearance into a sleek, curved form factor that matches conventional eyeglasses while maintaining optical functionality through total internal reflection at the curved interfaces
2Shape
If waveguides are integrated with curved eyeglass lenses, then fashion appeal and form factor are improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the waveguide function with the eyeglass lens by embedding the waveguide structure within the lens material itself. The waveguide is integrated during lens manufacturing, combining two previously separate components (waveguide and lens) into a single unified structure, which simplifies assembly and reduces the number of manufacturing steps despite the added complexity of integrating curved surfaces
Solution Approach 2:
The patent employs composite material structures where the waveguide is formed within the lens material. The lens is constructed as a composite structure combining the waveguide material (with higher refractive index) and the lens material, enabling simultaneous achievement of waveguide functionality and curved eyeglass appearance through integrated material composition
3Device complexity
If planar waveguides are used, then optical routing is straightforward, but visible seams and poor integration with curved lenses occur
Solution Approach 1:
The patent eliminates visible seams by matching the waveguide curvature to the lens curvature. The waveguide surfaces are shaped to be convex on the object side and concave on the eye side, creating seamless integration with the curved lens geometry. This curvature matching ensures that the waveguide follows the natural contour of the lens, eliminating discontinuities and visible seams that would occur with planar waveguides on curved surfaces
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables wearable heads-up displays to adopt a more streamlined and aesthetically appealing form factor, accommodating prescription lenses and enhancing user experience by embedding waveguides within the curved lens structure, reducing visible seams and allowing for flexible out-coupler placement.
Implementation Method 1
An optical waveguide operates under the principle of total internal reflection (TIR). TIR occurs when light remains in a first medium upon incidence at a boundary with a second medium because the refractive index of the first medium is greater than the refractive index of the second medium and the angle of incidence of the light at the boundary is above a specific critical angle
Implementation Method 2
an in-coupler physically coupled to a first area of the curved waveguide, the in-coupler to receive display light from the display light source and in-couple display light into the curved waveguide
Implementation Method 3
an out-coupler physically coupled to a second area of the curved waveguide, the out-coupler to receive display light from the curved waveguide and out-couple display light into the field of view of the eye of the user
Data Source
AI summary
Systems, devices, and methods that implement waveguides in curved transparent combiners that are well-suited for use in wearable heads-up displays (WHUDs) are described. Waveguide structures with in-couplers and out-couplers are integrated with curved eyeglass lenses to provide transparent combiners that substantially match the shape, size, and geometry of conventional eyeglass lenses and can, in some implementations, embody prescription curvatures to serve as prescription eyeglass lenses. The waveguides and in-/out-couplers are planar or curved depending on the implementation.WHUDs that employ such curved transparent combiners are also described.