Waveguide Projector Layout With Scanning Mirror for Low-Loss AR Display
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Solution Overview
Problem
Existing augmented reality systems face challenges in improving display quality and efficiency, particularly in achieving high optical throughput and reducing system complexity and cost.
Innovation Solution
A waveguide display system incorporating a waveguide with incoupling and outcoupling diffractive optical elements, a scanning mirror, and a collimating optical element, which utilizes a non-polarization-maintaining optical fiber and on-axis configurations to enhance light coupling and reduce aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional augmented reality display system is used, then the system structure is established, but the optical efficiency is low and light loss is high
Solution Approach 1:
The patent combines the scanning mirror and collimating optical element into a single integrated projector unit. This merging reduces the number of separate optical components and interfaces, thereby reducing light loss while maintaining the necessary optical functions for augmented reality display.
Solution Approach 2:
The integrated projector serves multiple functions: it acts as both the scanning mirror and the collimating optical element. This multi-functionality reduces the overall system complexity and minimizes the number of optical interfaces, thereby improving optical efficiency and reducing light loss.
2Illumination intensity
If multiple separate optical components are used, then the system is easier to manufacture, but the optical efficiency decreases and brightness is reduced
Solution Approach 1:
By integrating the scanning mirror and collimating optical element into a single projector unit, the patent reduces the number of optical interfaces where light loss occurs. This integration maintains high brightness while simplifying the assembly process through reduced component count.
Solution Approach 2:
The patent converts what would traditionally be separate components (scanning mirror and collimating element) into an integrated unit, transforming the potential harm of complex assembly into the benefit of reduced light loss and improved optical efficiency.
3Adaptability or versatility
If traditional optical paths are used, then the system is simpler to design, but the field of view is limited and image quality is reduced
Solution Approach 1:
The patent employs a folded optical path design that utilizes the waveguide structure to extend the optical path in a dimension perpendicular to the device thickness. This allows for a larger field of view and improved image quality without significantly increasing the device footprint or design complexity.
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 achieves improved optical efficiency, increased brightness, and reduced complexity by minimizing light loss and aberrations, enabling high-quality volumetric displays with enhanced field of view and depth planes.
Implementation Method 1
The incoupling DOE is configured to prevent the divergent reflected light beam from the scanning mirror from propagating to the outcoupling DOE in the waveguide through total internal reflection (TIR)
Implementation Method 2
a collimating optical element positioned adjacent to the first surface of the waveguide, the collimating optical element being configured to receive the divergent reflected light beam emitted from the scanning mirror through the incoupling DOE of the waveguide and to produce a collimated reflected light beam
Implementation Method 3
cause the collimated reflected light beam to propagate to the outcoupling DOE in the waveguide through total internal reflection (TIR)
Implementation Method 4
a waveguide having a first surface and a second surface, the waveguide including an incoupling DOE (diffractive optical element) and an outcoupling DOE
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A waveguide display system (1400), comprising a waveguide (1442) having a first surface (1421) and a second surface (1422), the waveguide(1442) including an incoupling diffractive optical element (1446), DOE, and an outcoupling DOE (1448); a point light source (1415) configured to provide a divergent input light beam (1411); a scanning mirror (1420) adjacent to the second surface (1422), configured to receive the divergent input light beam (1411) through the waveguide (1442) and to provide a divergent reflected light beam (1455); a collimating scanning optical element (1430) adjacent to the first surface (1421), configured to receive the divergent reflected light beam (1455) through the incoupling DOE (1446) and to produce a collimated reflected light beam (1460); wherein the incoupling DOE (1446) is configured to prevent the divergent reflected light beam (1455) from the scanning mirror (1420) from propagating to the outcoupling DOE (1448) through total internal reflection TIR; and cause the collimated reflected light beam (1460) to propagate to the outcoupling DOE (1448) through TIR.