Tilted Waveguide AR Device Using Polarization Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing augmented reality (AR) devices with waveguides face challenges in achieving a natural glasses-type appearance while maintaining an unobstructed viewing angle, especially when the waveguide is tilted.
Innovation Solution
The AR device incorporates a tilted waveguide with a polarization-conversion reflector and input/output couplers to ensure that light of the appropriate polarization is directed into and out of the waveguide, maintaining the viewing angle even when the waveguide is inclined.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the waveguide is tilted to achieve a natural glasses-type appearance, then the appearance structure is improved, but the viewing angle becomes obstructed
Solution Approach 1:
A polarization-conversion reflector is introduced as an intermediary optical element between the display and the tilted waveguide. This reflector converts the polarization state of light and redirects it at a specific angle, enabling the waveguide to be tilted for aesthetic purposes while still delivering light to the user's eye at the correct orientation, thus resolving the contradiction between appearance and viewing angle.
Solution Approach 2:
The patent utilizes polarization conversion as a parameter change mechanism. By changing the polarization state of light through the polarization-conversion reflector, the system can redirect light paths without physically adjusting the waveguide orientation, allowing the waveguide to maintain a tilted appearance while preserving optimal viewing angles through polarization-based light redirection.
2Shape
If the waveguide is tilted to improve appearance, then the glasses-type look is enhanced, but light transmission efficiency decreases
Solution Approach 1:
The polarization-conversion reflector acts as a mediator that preserves light energy by converting polarization states rather than absorbing or scattering light. This allows the tilted waveguide to maintain its aesthetic appearance while the reflector ensures efficient light transmission through polarization-based redirection, preventing energy loss that would otherwise occur from misaligned optical paths.
Solution Approach 2:
Instead of using mechanical alignment adjustments to optimize light transmission, the patent substitutes a polarization-based optical mechanism. The polarization-conversion reflector uses polarization state transformation to achieve light redirection, replacing what would otherwise require complex mechanical alignment systems to maintain transmission efficiency in a tilted configuration.
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 configuration allows the AR device to maintain a natural appearance and unobstructed viewing angle, even with a tilted waveguide, enhancing user comfort and visual experience.
Implementation Method 1
a polarization-conversion reflector provided opposite to an output side of the display, the polarization-conversion reflector converting the light of the first polarization into light of a second polarization that is orthogonal to the first polarization and reflecting the light of the second polarization
Implementation Method 2
an input-coupler inputting the light of the second polarization into the waveguide
Implementation Method 3
an output-coupler outputting light propagating in the waveguide
Data Source
AI summary
An augmented reality (AR) device is provided. The AR device includes a display configured to output light of a first polarization; a polarization-conversion reflector provided opposite to an output side of the display, the polarization-conversion reflector converting the light of the first polarization into light of a second polarization that is orthogonal to the first polarization and reflect the light of the second polarization; a waveguide having a flat plate shape, a normal line of a flat surface of the flat plate shape being inclined with respect to an optical axis of the light of the first polarization output from the display, a side of the waveguide being provided between the display and the polarization-conversion reflector; an input-coupler inputting the light of the second polarization into the waveguide; and an output-coupler outputting light propagating in the waveguide.