Waveguide Display Module Using Wavelength Division Multiplexing
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Solution Overview
Problem
Existing near-eye display modules in augmented reality have limited viewing angles due to the sensitivity of gratings to incident angles, and existing solutions for expanding viewing angles, such as splicing, are not capable of miniaturization.
Innovation Solution
A waveguide display module using a fiber scanning module and wavelength division multiplexing, where an image is segmented into sub-images and coupled through multiple layers of in-coupling and out-coupling units with specific wavelength configurations, allowing for broader viewing angles while reducing the number of scanning fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If splicing is used to expand viewing angles, then the viewing angle is improved, but the device complexity and size increase
Solution Approach 1:
The patent segments the image into multiple sub-images corresponding to different viewing angles. Each sub-image is modulated by light sources with specific wavelength ranges. The waveguide module contains multiple groups of in-coupling and out-coupling units, each group handling a specific wavelength range and viewing angle. This segmentation allows the system to achieve wide viewing angles without physically splicing multiple complete display systems, thereby reducing device complexity.
Solution Approach 2:
The patent introduces wavelength as an additional dimension for multiplexing. Instead of using multiple separate optical paths for different viewing angles (which would increase device complexity), the system encodes viewing angle information in the wavelength domain. Multiple sub-images with different viewing angles are transmitted through the same waveguide by assigning them different wavelength ranges, achieving wide viewing angles without increasing the physical device complexity.
2Adaptability or versatility
If multiple scanning fibers are used to achieve large viewing angle, then the viewing angle is improved, but the device complexity and size increase
Solution Approach 1:
The patent merges multiple viewing angle channels into a single scanning fiber by using wavelength division multiplexing. Instead of requiring one scanning fiber per viewing angle, the system combines multiple sub-images with different viewing angles into a single optical stream that is transmitted through one scanning fiber. The waveguide module then separates these wavelengths to deliver the appropriate viewing angles, reducing the number of scanning fibers from multiple to one.
Solution Approach 2:
The single scanning fiber serves multiple functions by transmitting multiple sub-images with different viewing angles simultaneously through wavelength division multiplexing. The waveguide module acts as a universal interface that handles multiple viewing angle channels through a single fiber connection, making the scanning fiber multi-functional rather than requiring dedicated fibers for each viewing angle.
3Volume of moving object
If wavelength division multiplexing is used with multiple in-coupling units, then the viewing angle is improved and miniaturization is achieved, but the manufacturing complexity increases
Solution Approach 1:
The patent implements a nested structure where multiple in-coupling units and out-coupling units are stacked or integrated within a compact waveguide module. Each unit handles a specific wavelength range and viewing angle, and they are arranged in a nested or layered configuration. This allows the module to achieve wide viewing angles and miniaturization while organizing the complex manufacturing requirements in a structured, hierarchical manner that facilitates production.
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 approach enables a large viewing angle and miniaturization of near-eye display modules by maintaining resolution and viewing angle, facilitating the production of compact near-eye display devices.
Implementation Method 1
Each of the image generation sub-units generates through modulation mixed light beams of N sub-images through wavelength division multiplexing
Implementation Method 2
the light beam is coupled into the waveguide 4 at a certain angle by the in-coupling grating 3 for total reflection transmission
Implementation Method 3
the light beam is coupled into the waveguide 4 at a certain angle by the in-coupling grating 3 for total reflection transmission
Implementation Method 4
the out-coupling grating 5 disposed in the waveguide at a position corresponding to an exit pupil couples the light beam transmitted in the waveguide out to a human eye
Data Source
AI summary
Disclosed are a waveguide display module, and an image generation module and application corresponding thereto. By wavelength division multiplexing, an image generation unit generates through modulation mixed light beams containing at least two groups of sub-images of different wavelengths. The mixed light beams generated through modulation by the image generation unit are coupled into a waveguide module, which module has in-coupling units arranged in multiple layers and out-coupling units arranged in multiple layers, an in-coupling unit in each layer being configured to couple in light of different wavelength ranges. Emergent images, formed after mixed light beams of an image to be displayed generated by the image generation unit are coupled out by the out-coupling units of the waveguide module, are spliced into the image to be displayed.