Controllable Waveguide Apertures for Near-Eye Displays
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Solution Overview
Problem
Conventional waveguide displays for near-eye applications are limited by chromatic aberrations and restricted exit pupil size due to diffractive optics, which hinder the transmission of multiple wavelengths and angles, and struggle to maintain image quality and ambient environment visibility.
Innovation Solution
The implementation of controllable apertures with transformable diffractive optics that can shift between transparent and diffractive states, allowing for selective handling of beam angles and wavelengths, and an intermediate diffractive optic for reorienting beams, thereby expanding the viewing area and enhancing image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional diffractive optics are used to transmit angular image information, then virtual images can be formed, but chromatic aberrations occur due to wavelength-dependent diffraction angles
Solution Approach 1:
The aperture is divided into multiple independently controllable segments that can be selectively activated. Each segment can be optimized for specific wavelength ranges or angle ranges, allowing chromatic aberrations to be managed by activating only the appropriate segments for the current operational conditions.
Solution Approach 2:
The aperture segments are made dynamically controllable through electronic actuation, allowing the system to adaptively adjust which segments are active based on the desired wavelength range or angle range. This dynamic control enables optimization of diffraction performance for different operational modes.
2Manufacturing precision
If multiple waveguides or complex diffractive optics are used to mitigate chromatic aberrations, then image quality improves, but device complexity increases
Solution Approach 1:
Instead of using multiple separate waveguides, the invention segments the aperture within a single waveguide into multiple controllable regions. This achieves wavelength-selective or angle-selective diffraction control without requiring multiple physical waveguide structures.
Solution Approach 2:
A single waveguide structure is designed to perform multiple functions through the controllable aperture segments, which can be configured for different wavelength ranges, angle ranges, or operational modes, replacing the need for multiple specialized waveguides.
3Manufacturing precision
If diffractive optics are used to eject light beams, then virtual images are formed, but exit pupil size is limited due to beam spreading
Solution Approach 1:
The output aperture is segmented into multiple independently controllable regions that can be selectively activated to control the angular distribution of ejected beams. By coordinating the activation of different segments, the system can expand the effective exit pupil size while maintaining proper virtual image formation.
4Manufacturing precision
If output diffractive optics are optimized for multiple wavelengths and angles, then image quality improves, but transmissivity for ambient environment viewing deteriorates
Solution Approach 1:
The aperture segments are dynamically controllable, allowing the system to switch between different operational states. When ambient environment viewing is desired, the diffractive segments can be deactivated to maximize transmissivity. When virtual image display is active, only the necessary segments are activated to minimize impact on ambient light transmission while maintaining image quality.
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 solution enables expanded viewing areas and improved image quality by optimizing the operation of controllable components to manage multiple angles and wavelengths, while also supporting a view of the ambient environment, thus overcoming the limitations of conventional waveguide displays.
Implementation Method 1
Each of the controllable components of the input aperture is selectively operable as a diffractive optic for injecting a subset of the angularly related beams
Implementation Method 2
The image information propagates along the waveguides as a plurality of angularly related beams that are internally reflected along the waveguide
Implementation Method 3
Each of the controllable components of the output aperture is selectively operable as a diffractive optic for ejecting a corresponding subset of the angularly related beams out of the waveguide
Data Source
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AI summary
A near-eye display includes an image generator that generates angularly related beams over a range of angles for forming a virtual image and a waveguide that propagates the angularly related beams over a limited range of angles. An input aperture of the waveguide includes a plurality of controllable components that are selectively operable as diffractive optics for injecting subsets of the angularly related beams into the waveguide. An output aperture of the waveguide includes a plurality of controllable components that selectively operable as diffractive optics for ejecting corresponding subsets of the angularly related beams out of the waveguide toward an eyebox. A controller synchronizes operation of the controllable components of the output aperture with the propagation of different subsets of angularly related beams along the waveguide for ejecting the subsets of angularly related beams out of the waveguide for presenting the virtual image within the eyebox.