Imaging Waveguide Reflectance Camouflage for Hidden Diffractive Gratings
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Solution Overview
Problem
Existing augmented and mixed reality devices suffer from visible diffractive elements that detract from their aesthetic appearance, making them less appealing to onlookers.
Innovation Solution
Incorporation of non-diffractive nanostructures on the waveguide combiner surface to modulate visible reflectance, camouflaging the diffractive gratings and maintaining uniform reflectance across the surface, thereby masking the presence of diffractive elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If diffractive grating regions are used for image projection, then optical functionality is achieved, but aesthetic appearance deteriorates due to visible diffractive elements
Solution Approach 1:
The patent applies different surface properties to different regions of the waveguide combiner. The active regions contain diffractive gratings for optical functionality, while the inactive regions are made visually uniform and non-diffractive to improve aesthetics. This local differentiation allows each region to serve its specific purpose without compromising the other.
Solution Approach 2:
The patent introduces an intermediary layer or coating on the waveguide combiner surface that selectively masks the visual appearance of diffractive elements in inactive regions while preserving optical functionality in active regions. This intermediary element bridges the conflict between visible gratings and aesthetic appearance.
2Shape
If uniform reflectance is achieved across the surface, then aesthetic appearance improves, but visibility of diffractive gratings worsens
Solution Approach 1:
The patent modifies the optical properties of the waveguide combiner surface by applying coatings or treatments that alter reflectance characteristics. By adjusting the optical appearance (color, reflectance, transparency) of different regions, the patent makes diffractive gratings less visible while maintaining uniform aesthetics across the surface.
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
Improves the aesthetic appearance of augmented and mixed reality devices by reducing the visibility of diffractive gratings while maintaining functional performance for image projection.
Implementation Method 1
an array of non-diffractive unit cell structures imprinted in a region outside the input region and output region having a visible reflectance similar to the output region so as to camoufl-age the output region
Data Source
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AI summary
An optical waveguide combiner includes an optical waveguide substrate and an optical input region. The optical input region includes an optical input diffractive grating integrated in, or disposed on, the optical waveguide substrate. An optical output region includes an optical output diffractive grating integrated in, or disposed on, the optical waveguide substrate, At least one non-diffractive region includes at least one optical non- diffractive array of nanostructures, wherein said at least one optical non- diffractive array of nanostructures is integrated in, or disposed on, the object side of said optical waveguide substrate and at least partially surrounds at least said optical output grating; wherein the external visible reflectance of said at least one non- diffractive array of nanostructures is substantially equal to the external visible reflectance of said optical output grating.