Micro Mirror Array Aperture Stop for AR Depth of Field
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current augmented reality (AR) display technologies face challenges in effectively overlaying virtual content with real-world environments, particularly in maintaining a clear depth of field and efficiently utilizing display areas to provide a seamless rectangular field of view.
Innovation Solution
The implementation of an AR display method and apparatus that includes a micro mirror array coupled with an optical assembly, where the micro mirror array serves as an aperture stop, allowing for increased depth of field and precise rectangular field of view by determining and displaying virtual content in specific effective areas on a display screen, corresponding to the layout and spacing of the micro mirror array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional AR display elements (off-axis curved surface reflection elements, free-form surface prisms, geometric waveguides or holographic waveguides) are used, then virtual content can be displayed overlapped with real world environment, but the depth of field remains limited and display area utilization is inefficient
Solution Approach 1:
The display screen is divided into multiple effective display areas corresponding to individual micro mirror units, with each area displaying virtual content that maps to a specific micro mirror's field of view. This segmentation allows the aperture stop function to be distributed across multiple discrete units, increasing overall depth of field while maintaining manageable system complexity
Solution Approach 2:
The patent uses a micro mirror array as an aperture stop copy that replicates the aperture function across multiple discrete mirrors. Each micro mirror unit acts as a copy of the aperture stop, and collectively they provide the depth of field enhancement without requiring a single large complex aperture mechanism
2Area of stationary object
If the entire display screen is used for virtual content display, then display area utilization is maximized, but the rectangular field of view becomes distorted and does not match the micro mirror array geometry
Solution Approach 1:
Different regions of the display screen are assigned different functions: only specific rectangular areas corresponding to micro mirror field of view are used for virtual content display, while other areas remain unused or serve different purposes. This local quality approach ensures that the displayed content maintains the correct rectangular geometry matching the micro mirror array, even though it utilizes only a portion of the total display area
Solution Approach 2:
Instead of trying to make the entire display screen map to a rectangular field of view, the patent inverts the approach by defining the effective display areas based on the micro mirror array geometry and then mapping virtual content to these predefined areas. This inversion resolves the geometric distortion issue by starting with the correct geometry and working outward
3Area of moving object
If a large aperture is used to increase field of view, then the field of view increases, but the depth of field decreases
Solution Approach 1:
The aperture function is segmented across multiple discrete micro mirror units arranged in an array. Each micro mirror unit provides a portion of the total field of view while acting as an independent aperture stop, allowing the system to achieve both wide field of view and deep depth of field simultaneously through the collective action of multiple small apertures
Solution Approach 2:
Multiple micro mirror units working together as a combined aperture system merge their individual aperture stop functions to create an effective large aperture for wide field of view while maintaining the depth of field characteristics through the distributed aperture architecture
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 enhances the depth of field for virtual content and allows for efficient display of virtual information overlaid on real-world scenes, providing a clear and integrated rectangular field of view, even when viewing real scenes of different spatial depths.
Implementation Method 1
the light emitted from the display assembly is reflected by the micro mirror array
Implementation Method 2
a micro mirror in the micro mirror array may serve as an aperture stop, which has a relative small size. By the function of the aperture stop, the depth of field of the virtual content can be increased consequently
Implementation Method 3
determining a matrix spacing of a plurality of effective projection areas after being projected by via a projection assembly
Data Source
AI summary
Provided are an AR display method, an AR display apparatus and an AR display device, the device including: a display assembly used for displaying a virtual content, an optical assembly, and a micro mirror array coupled to the optical assembly; the micro mirror array is located on a propagation path of light emitted from the display assembly.