Two-Dimensional Grating Light Guide for Wide-Field Near-Eye Displays
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Solution Overview
Problem
Existing near-eye display apparatuses face challenges in increasing the field of view while maintaining a simple structure and reducing costs, as multiple light guide plates are required, leading to increased complexity and weight.
Innovation Solution
A light guide with a two-dimensional grating disposed on a light guide plate, allowing one light guide plate to diffract incident light into multiple emergent beams, using symmetrically arranged grating vectors to expand the field of view and compensate for losses, thus simplifying the structure and reducing the need for multiple plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple light guide plates are used to increase the field of view, then the field of view increases, but the device complexity and weight increase
Solution Approach 1:
The patent transitions from using multiple separate light guide plates (one-dimensional approach) to a single light guide plate with a two-dimensional grating structure. The two-dimensional grating includes grating units arranged in both first and second directions, creating multiple diffraction paths that expand the field of view without requiring multiple plates. This dimensional change in the grating structure allows one plate to perform the function of multiple plates.
Solution Approach 2:
The single light guide plate with two-dimensional grating performs multiple functions simultaneously: it diffracts light in multiple directions, supports multiple transmission paths (including compensation paths), and achieves a large field of view all within one component. This multi-functional design replaces what would traditionally require multiple specialized light guide plates.
2Area of stationary object
If multiple light guide plates are used to increase the field of view, then the field of view increases, but the weight increases
Solution Approach 1:
The patent uses a two-dimensional grating structure with grating units arranged in both first and second directions to create multiple diffraction paths within a single light guide plate. This allows one plate to achieve the field of view expansion that would traditionally require multiple plates, thereby reducing the total weight of the light guide assembly.
3Area of stationary object
If multiple light guide plates are used to increase the field of view, then the field of view increases, but the manufacturing cost increases
Solution Approach 1:
The patent implements a two-dimensional grating with grating units arranged in multiple directions on a single light guide plate, enabling one plate to perform the function of multiple plates. This reduces the total number of components that need to be manufactured, assembled, and quality-checked, thereby lowering manufacturing costs despite the increased complexity of the grating pattern itself.
4Area of stationary object
If multiple light guide plates are used to increase the field of view, then the field of view increases, but the assembly process becomes more complex
Solution Approach 1:
The patent merges the functions of multiple light guide plates into a single integrated light guide plate with a two-dimensional grating. The grating units are arranged in both first and second directions to create multiple diffraction paths and compensation paths within one component. This consolidation eliminates the need for assembling multiple separate plates, significantly simplifying the assembly process while maintaining a large field of view.
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 enables a large field of view of at least 60° in near-eye display apparatuses, improving user experience while minimizing the number of components and costs, and facilitating miniaturization.
Implementation Method 1
The grating unit is configured to diffract one incident light beam into at least three emergent light beams
Data Source
AI summary
The present disclosure relates to light guides and near-eye display apparatuses. One example light guide includes a light guide plate and a two-dimensional grating that is disposed on a surface of the light guide plate. The two-dimensional grating includes a plurality of grating units arranged in a planar shape, the grating units are arranged at an interval of a first distance along a first direction and at an interval of a second distance along a second direction, and the first direction intersects with the second direction. The two-dimensional grating includes a light egress area and a light ingress area that are arranged along a third direction, and a fourth direction is perpendicular to the third direction.