Diffractive Light Guide Plate With Stress Compensation for AR Optics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing diffraction light guide plates for Augmented Reality (AR), Mixed Reality (MR), and Virtual Reality (VR) are thick and heavy, and the substrates with pattern layers on one surface are prone to stress-induced transformation, leading to degraded display performance due to light scattering and image quality issues.
Innovation Solution
A diffraction light guide plate design featuring a first diffraction substrate with a first diffraction grating layer on one surface and a second diffraction grating layer on the other, along with a second diffraction substrate having a third diffraction grating layer and a stress compensation layer on the other surface, which separates specific wavelength ranges of light and compensates for stress to prevent substrate transformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diffraction light guide plate uses three substrates with pattern layers on one surface, then light diffraction function is achieved, but thickness and weight increase
Solution Approach 1:
The patent merges multiple diffraction grating layers onto fewer substrate(s) by forming first, second, and third diffraction grating layers on the same substrate surface. This integration reduces the number of separate substrates needed while maintaining the light diffraction function across different wavelength ranges (red: 550-700nm, green: 400-550nm, blue: 450-650nm), thereby reducing overall thickness and weight.
2Reliability
If a pattern layer is formed on one surface of the substrate, then light diffraction is enabled, but substrate transformation occurs due to stress
Solution Approach 1:
The patent uses a composite structure consisting of multiple diffraction grating layers (first, second, and third diffraction grating layers) with different pitch values designed for different wavelength ranges. This composite arrangement distributes stress across multiple functional layers rather than concentrating it in a single pattern layer, reducing the overall stress impact on the substrate and preventing substrate transformation while maintaining comprehensive light diffraction capability.
3Reliability
If multiple substrates are stacked to achieve light separation, then display performance improves, but device complexity increases
Solution Approach 1:
The patent combines multiple diffraction grating functions into a single integrated structure by forming first, second, and third diffraction grating layers on the same substrate. Each layer targets specific wavelength ranges (red, green, blue) with optimized pitch values, achieving comprehensive light separation and enhanced display performance without requiring multiple separate substrates, thereby reducing structural complexity.
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 effectively reduces the thickness and weight of the diffraction light guide plate, prevents substrate transformation due to stress, and enhances light separation efficiency, reducing cross-talk and improving image quality in AR, MR, and VR applications.
Implementation Method 1
the first diffraction grating layer separates light having a wavelength of 550 nm or more and 700 nm or less
Implementation Method 2
the second diffraction grating layer separates light having a wavelength of 400 nm or more and 550 nm or less
Implementation Method 3
the third diffraction grating layer separates light having a wavelength of 450 nm or more and 650 nm or less
Data Source
Figure 1A
Figure 1B
Figure 2~3A
AI summary
A diffraction light guide plate, including: a first diffraction substrate; and a second diffraction substrate provided on the first diffraction substrate. The first diffraction substrate includes a first diffraction grating layer on one surface and a second diffraction grating layer on an opposite surface. The second diffraction substrate includes a third diffraction grating layer on one surface and a stress compensation layer on an opposite surface. The first diffraction grating layer separates light having a wavelength of 550 nm or more and 700 nm or less, the second diffraction grating layer separates light having a wavelength of 400 nm or more and 550 nm or less, the third diffraction grating layer separates light having a wavelength of 450 nm or more and 650 nm or less, and the stress compensation layer has stress in the same direction as a direction of stress of the third diffraction grating layer.