Fourier-beam shaper waveguide for compact AR display
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Solution Overview
Problem
Current augmented reality (AR) display systems are bulky due to the need for a distance between a spatial light modulator and a lens to project images onto the user's eyes, which increases the volume of the optical system and requires additional optical devices like lenses.
Innovation Solution
A display apparatus incorporating a Fourier-beam shaper with a waveguide, input coupler, and spatial converter using selective transmission elements that time-sequentially output light beams through different regions to form a frame image in external space, reducing the need for additional optical devices and allowing for a more compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a lens and spatial light modulator are used to project images onto the user's eyes, then image quality is improved, but the volume of the optical system increases
Solution Approach 1:
The patent extracts and removes the lens from the optical system by using a waveguide with input/output couplers that directly couple light beams into and out of the waveguide. This eliminates the need for traditional lens-based image projection while maintaining image quality, thereby reducing the overall volume of the optical system.
Solution Approach 2:
The waveguide structure serves multiple functions: it acts as both the light guiding medium and the image projection interface. The input coupler receives light beams and couples them into the waveguide, while the output coupler extracts and projects the image onto the user's eyes, replacing the traditional multi-component optical system with a integrated waveguide-based solution.
2Adaptability or versatility
If additional optical devices like lenses are used, then image projection capability is improved, but device complexity increases
Solution Approach 1:
The patent removes the lens from the optical system by using waveguide-based input and output couplers. These couplers directly couple light beams into and out of the waveguide, eliminating the need for additional optical devices while maintaining image projection capability.
Solution Approach 2:
The waveguide structure integrates multiple functions: it guides light from the spatial light modulator, projects the image onto the user's eyes, and eliminates the need for separate lens components. This multi-functional integration reduces device complexity while preserving image projection capabilities.
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 solution enables a compact and efficient display system that reduces the volume of the optical system, allowing for smaller light sources and spatial light modulators, and eliminates the need for additional optical devices like lenses, while maintaining image quality and user experience.
Implementation Method 1
The input coupler receives collimated first wavelength light from an Input Image Node causes the light to travel within the first waveguide via total internal reflection between the first surface and the second surface to the fold grating
Implementation Method 2
The fold grating provides pupil expansion in a first direction directs the light to the output grating via total internal reflection between the first surface and the second surface
Implementation Method 3
causes the light to travel within the first waveguide via total internal reflection between the first surface and the second surface
Data Source
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AI summary
Provided are a Fourier-beam shaper and a display apparatus including the Fourier-beam shaper. The Fourier-beam shaper includes: a waveguide; an input coupler configured to direct a plurality of light beams toward the waveguide in a time-sequential manner; and a spatial converter configured to output the plurality of light beams traveling in the waveguide through spatially different regions of the spatial converter.