Freeform VR Optics With Variable Focus for Accommodation Conflict
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Solution Overview
Problem
Conventional stereoscopic displays suffer from accommodation-convergence conflict due to decoupling of the accommodation cue from the convergence cue, tying the accommodation cue to a fixed distance, which limits the effectiveness of virtual and augmented reality systems.
Innovation Solution
A freeform optical system with addressable focus is employed, utilizing primary and secondary freeform optical elements and a variable focusing system to independently control focal distances, addressing both accommodation and convergence cues without tying them to a fixed distance, and incorporating a computing device to determine light ray projection and synthesis for enhanced stereoscopic imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional stereoscopic displays decouple accommodation cue from convergence cue and tie accommodation to fixed distance, then device complexity is reduced, but image quality and user comfort deteriorate due to accommodation-convergence conflict
Solution Approach 1:
The patent implements dynamic focus adjustment capability that allows the optical system to change focal distances in real-time based on the displayed content depth. The variable focus mechanism enables the accommodation cue to dynamically match the convergence cue, resolving the accommodation-convergence conflict while maintaining system feasibility through controlled complexity
Solution Approach 2:
The system changes the optical parameter of focal distance to create multiple focal planes. By varying the focus parameter dynamically, the system provides different accommodation distances that correspond to different depth planes in the stereoscopic image, allowing the accommodation cue to match the convergence cue at each depth level
2Manufacturing precision
If freeform optical elements with variable focus are used, then image quality and stereoscopic effect are improved, but device complexity increases
Solution Approach 1:
The optical system is segmented into multiple functional components: freeform optical elements for field of view expansion, variable focus mechanism for depth control, and waveguide for light propagation. Each component performs a specific function, allowing the complex overall system to be managed through modular design while achieving high image quality
Solution Approach 2:
The freeform optical elements introduce additional optical dimensions by creating multiple focal planes along the depth axis. This dimensional expansion allows light to be directed to different depths, enabling true stereoscopic imaging with proper accommodation cues while the waveguide integrates these functions in a compact form factor
3Reliability
If multiple focal planes are created with variable focusing system, then accommodation-convergence conflict is resolved, but ease of operation deteriorates
Solution Approach 1:
The variable focus mechanism operates automatically based on the depth information of the displayed content. The system self-adjusts the focal plane without requiring manual user intervention, using sensors or content analysis to determine the appropriate focus distance, thereby maintaining ease of operation while resolving the accommodation-convergence conflict
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 resolves the accommodation-convergence conflict by dynamically adjusting focal distances, providing clear and immersive stereoscopic images in virtual and augmented reality applications, expanding the field of view, and improving image quality.
Implementation Method 1
The primary freeform optical element comprises one or more refractive surfaces and one or more reflective surfaces to allow the injected light rays to deflect or reflect between these surfaces
Implementation Method 2
The primary freeform optical element comprises one or more refractive surfaces and one or more reflective surfaces to allow the injected light rays to deflect or reflect between these surfaces
Implementation Method 3
a variable focusing system to produce an intermediate pupil and to change a focal distance of the focal plane
Data Source
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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.