Stacked Waveguide Combiner Plates for Mixed Reality FOV
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional waveguide combiners for mixed-reality display systems face limitations in field of view (FOV) due to total internal reflection constraints and fabrication complexities, particularly in integrating tilted and non-tilted mirror structures within a single plate, which can result in lower manufacturing yields and increased costs.
Innovation Solution
A waveguide combiner with stacked plates of reflective optical elements (ROEs) where the top and bottom plates share a common footprint and are aligned, with the top plate providing horizontal exit pupil expansion and the bottom plate providing vertical expansion, allowing for split functionality and reduced fabrication complexity, and optionally incorporating supplemental plates for additional features like filtering and beam steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If tilted and non-tilted mirror structures are integrated within a single plate, then the field of view is improved, but manufacturing complexity increases and fabrication yields decrease
Solution Approach 1:
The waveguide combiner is divided into multiple separate plates, each containing only non-tilted mirror structures. This segmentation allows each plate to be manufactured independently using standard fabrication processes, avoiding the complexity of integrating tilted mirrors while still achieving the desired field of view through the stacked configuration.
Solution Approach 2:
The solution moves from a two-dimensional integration problem (tilted and non-tilted mirrors in one plate) to a three-dimensional stacked configuration. By distributing mirror structures across multiple plates in the vertical dimension, the system achieves the required optical functionality without the fabrication complexity of in-plane integration.
2Area of stationary object
If tilted mirror structures are integrated in a single plate, then the field of view is improved, but manufacturing yields and precision are reduced
Solution Approach 1:
By segmenting the waveguide combiner into multiple plates with only non-tilted mirrors, each component can be manufactured with standard precision tolerances. The alignment between plates is simplified because all mirrors are non-tilted, eliminating the complex angular alignment requirements that would arise from integrating tilted mirrors in a single plate.
3Device complexity
If multiple reflective optical elements are integrated in one waveguide, then the device complexity is reduced, but fabrication complexity increases
Solution Approach 1:
The waveguide combiner is segmented into multiple separate plates, each containing a subset of the required reflective optical elements. This allows each plate to be manufactured using simpler, more standardized processes, while the overall device functionality is achieved through the stacked configuration of these simpler components.
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
This design enhances the mixed-reality user experience by increasing the field of view, improving angular resolution, and simplifying fabrication, while enabling features such as color uniformity, contrast enhancement, and vision correction integration.
Implementation Method 1
A top plate in the stack of plates includes an input coupler, such as a prism, for in-coupling light for virtual images from a display engine into the waveguide combiner
Implementation Method 2
virtual image light is coupled by the bottom ROE to the see-through waveguide and propagates through total internal reflection to the out-coupling ROE
Implementation Method 3
The top plate also includes a top ROE comprising a cascaded array of mirror elements in a waveguide that horizontally expands an exit pupil of the virtual images
Data Source
AI summary
Disclosed are a mixed-reality optical waveguide-based combiner apparatus that includes stacked plates of reflective optical elements (ROEs) and associated methods of fabrication. ROEs in the plates of the waveguide combiner share a commonly shaped and sized footprint and are aligned in the stack. A top plate in the stack of plates includes an input-coupler, such as a prism, for in-coupling light for virtual images from a display engine into the waveguide combiner. The top plate also includes a top ROE comprising a cascaded array of mirror elements in a waveguide that horizontally expands an exit pupil of the virtual images and couples the light to a corresponding bottom ROE, disposed in a bottom plate in the stack, comprising a cascaded array of mirror elements in a waveguide. The bottom ROE couples the virtual image light to an output coupler in the bottom plate which out-couples light from the waveguide combiner.