Waveguide Grating Layout for Uniform AR Glasses Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing augmented reality (AR) glasses struggle with inefficient light guiding and non-uniform brightness distribution due to the limitations of current grating structures in waveguide plates, leading to suboptimal image quality.
Innovation Solution
A light-transmitting device with a waveguide plate and multiple grating regions, including a bulk grating structure for efficient light entry and nano-microstructure gratings for redirection and emission, along with a buffer layer to enhance energy efficiency and uniformity, utilizing specific grating height and area ratios and sub-region designs to optimize light distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional grating structures are used in waveguide plates, then the device complexity is reduced, but the light guiding efficiency deteriorates and brightness uniformity is poor
Solution Approach 1:
The waveguide plate is divided into multiple grating regions (first, second, and third grating regions) with different grating structures optimized for specific functions: the first region for light entry, the second for redirection, and the third for emission. This segmentation allows each region to be optimized independently for its specific optical function, improving overall light guiding efficiency while maintaining manageable device complexity through functional specialization.
Solution Approach 2:
Different grating structures are applied to different regions of the waveguide plate based on local optical requirements. The first grating region uses a structure optimized for light coupling, the second region uses a different structure for light redirection, and the third region uses yet another structure for light emission. This local optimization ensures that each region performs its specific function with maximum efficiency, resolving the contradiction between overall efficiency and uniform complexity.
2Illumination intensity
If uniform grating structures are used across the waveguide plate, then the manufacturing process is simplified, but the brightness distribution becomes non-uniform
Solution Approach 1:
The waveguide plate is divided into multiple grating regions (first, second, and third grating regions) with different grating structures optimized for specific functions: the first region for light entry, the second for redirection, and the third for emission. This segmentation allows each region to be optimized independently for its specific optical function, improving overall light guiding efficiency while maintaining manageable device complexity through functional specialization.
Solution Approach 2:
Different grating structures are applied to different regions of the waveguide plate based on local optical requirements. The first grating region uses a structure optimized for light coupling, the second region uses a different structure for light redirection, and the third region uses yet another structure for light emission. This local optimization ensures that each region performs its specific function with maximum efficiency, resolving the contradiction between overall efficiency and uniform complexity.
3Use of energy by moving object
If grating structures with larger height are used, then the light coupling efficiency is improved, but the energy loss increases
Solution Approach 1:
The patent optimizes the height parameter of grating structures by establishing specific height ranges for different grating regions. The first grating structure has a height within a specific range to optimize light coupling, while the second and third grating structures have different height ranges optimized for their respective functions of light redirection and emission. This parameter optimization ensures maximum light coupling efficiency while minimizing energy loss through appropriate height selection for each functional region.
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 proposed design improves grating coupling efficiency by approximately 57%, resulting in higher and more uniform brightness in projected images for AR glasses, enhancing user experience.
Implementation Method 1
Through the diffraction effect of the grating, the light emitted by a small projector equipped with the glasses is guided through the waveguide plate
Implementation Method 2
The second grating structure is configured to receive light from the first grating region and redirect the light
Implementation Method 3
The third grating structure is configured to receive light from the second grating region and emit the light out of the waveguide plate
Data Source
AI summary
A light-transmitting device includes a waveguide and first, second, and third grating regions. The first grating region is located on a first or a second surface of waveguide and has a first grating structure. The first grating structure allows a light to enter the waveguide. The second grating region is located on the first surface and has a second grating structure. The second grating structure is receives the light from the first grating region and to redirect the light. The third grating region is located on the first surface and has a third grating structure. The third grating structure receives the light from the second grating region and allows the light to leave the waveguide. A height of the second grating structure and a height of the third grating structure are less than the one-tenth of a height of the first grating structure.