Freeform Optical Displays with Addressable Focus for VR/AR Comfort
Solution Overview
Problem
Conventional stereoscopic displays suffer from accommodation-convergence conflict, where the accommodation cue is tied to a fixed distance, decoupling it from the convergence cue, leading to discomfort and inefficiencies in virtual and augmented reality systems.
Innovation Solution
A freeform optical system with addressable focus is employed, utilizing primary and secondary freeform optical elements in a tiled arrangement to expand the field of view and incorporate a variable focusing system that adjusts focal distances independently for each focal plane, addressing both accommodation and convergence cues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed focal distance is used in conventional stereoscopic displays, then the optical system is simple, but the accommodation-convergence conflict arises causing discomfort
Solution Approach 1:
The patent implements a variable focusing system that dynamically adjusts the focal distance of the optical system. This allows the accommodation cue to be decoupled from the convergence cue, enabling independent control of focal plane positioning. The dynamic adjustment mechanism resolves the accommodation-convergence conflict by allowing the focal distance to change while maintaining the desired convergence point, thereby improving user comfort without requiring a completely new optical architecture.
Solution Approach 2:
The system changes the focal distance parameter of the optical system to resolve the contradiction. By varying the focal distance independently from the convergence distance, the system can present stereoscopic images at different depths while maintaining proper accommodation cues. This parameter change approach allows the optical system to adapt to different viewing conditions and depth requirements, improving user comfort while managing system complexity through controlled parameter variation.
2Area of stationary object
If conventional optical elements are used, then the device structure is simple, but the field of view is limited
Solution Approach 1:
The patent divides the optical system into multiple discrete optical elements arranged in a tiled configuration. Each optical element contributes to a portion of the overall field of view, and their combined arrangement creates an expanded total field of view. This segmentation approach allows the system to achieve a wider field of view by combining multiple smaller optical components rather than relying on a single complex element, managing structural complexity through modular design.
Solution Approach 2:
The patent extends the optical system in multiple spatial dimensions by arranging optical elements in a tiled configuration. This dimensional expansion allows the system to cover a broader angular range and provide an expanded field of view in both horizontal and vertical directions. By utilizing multiple dimensions for element arrangement, the system achieves extended viewing coverage while maintaining a manageable structure through systematic spatial organization.
3Adaptability or versatility
If focal distance is fixed, then the optical system is stable, but it cannot address both accommodation and convergence cues independently
Solution Approach 1:
The variable focusing system introduces dynamic adjustability to the optical system, enabling independent control of focal distance while maintaining system stability through controlled mechanisms. The dynamic focal adjustment allows the system to adapt to different accommodation requirements while preserving the overall structural stability and optical path consistency, achieving both adaptability and stability simultaneously.
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 system effectively resolves the accommodation-convergence conflict by allowing independent adjustment of focal distances, providing clear and comfortable stereoscopic images in virtual and augmented reality applications.
Implementation Method 1
one or more freeform optical elements may be identified... a primary freeform optical element may include one or more refractive surfaces
Implementation Method 2
one or more freeform optical elements may be identified... one or more reflective surfaces
Implementation Method 3
a variable focusing system to change a focal distance of a focal plane... alter a focal length of the variable focus mechanism
Data Source
AI summary
Several unique hardware configurations and methods for freeform optical display systems are disclosed. A freeform display system includes primary freeform optical element(s) and secondary freeform optical element(s) in tiled arrangements to expand the horizontal field of view (FOV) or the vertical field of view. The system may include a variable focusing system that produces intermediate pupil and changes the focal distance of a single focal plane or switches among multiple focal planes for rendering objects in focus while resolving accommodation-convergence conflict. The system may map light samples to appropriate light rays in physical space and use a cluster of projectors to project the mapped light rays to produce the light field of the virtual display content. Methods for making tiled freeform optical display systems and methods for producing virtual content with variable focus freeform optics and rendering light fields are also disclosed.