Slanted Grating Waveguide for AR Display Viewing Angle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current augmented reality display devices face challenges in maintaining image clarity and resolution when viewed from various angles, often resulting in distorted or blurry images due to non-optimal alignment and viewing perspectives.
Innovation Solution
A grating structure within a waveguide is developed, featuring a substrate with a grating layer and a recess that changes depth, forming slanted grating structures to improve light propagation and control diffraction, enhancing image clarity and resolution across a wider viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a traditional planar grating structure is used in the waveguide, then the manufacturing process is simple, but the image clarity and resolution deteriorate when viewed from non-optimal angles
Solution Approach 1:
The patent applies asymmetry by transitioning from a traditional planar (symmetric) grating structure to a slanted grating structure with asymmetric geometry. The grating lines are inclined at a specific angle relative to the waveguide surface, creating an asymmetric configuration that optimizes light diffraction and refraction properties. This asymmetric design enables improved image clarity and resolution across a wider viewing angle range while maintaining manufacturing feasibility through standard semiconductor fabrication processes
Solution Approach 2:
The patent implements dimensionality change by evolving the grating structure from a two-dimensional planar configuration to a three-dimensional slanted configuration. The grating lines are no longer flat on the surface but extend into the third dimension with a specific inclination angle. This dimensional transformation allows the grating to control light propagation more effectively, providing superior image quality and broader viewing angles while remaining compatible with existing manufacturing capabilities
2Manufacturing precision
If the grating depth is uniform across the waveguide, then the manufacturing process is simplified, but the light propagation control and diffraction are insufficient
Solution Approach 1:
The patent applies local quality by implementing a grating structure where the depth varies locally across different regions of the waveguide. Specifically, the grating depth is maximum at the input coupling region and gradually decreases toward the output coupling region, creating a depth gradient. This localized variation in grating depth optimizes light propagation control and diffraction efficiency at different positions, enabling superior image quality while being fabricated using standard semiconductor processes with controlled etching depth variations
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 significantly improves image clarity and resolution by controlling light wavelengths and reducing distortion, allowing for a more uniform light output and increased viewing angle, thus addressing the limitations of existing augmented reality display technologies.
Implementation Method 1
A grating structure within a waveguide is developed, featuring a substrate with a grating layer and a recess that changes depth, forming slanted grating structures to improve light propagation and control diffraction
Data Source
AI summary
An apparatus with a grating structure and a method for forming the same are disclosed. The grating structure includes forming a recess in a grating layer. A plurality of channels is formed in the grating layer to define slanted grating structures therein. The recess and the slanted grating structures are formed using a selective etch process.