Transparent Waveguide Display With Passive SBG Field Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current transparent displays, such as helmet-mounted displays, struggle to provide a compact, lightweight, and unobtrusive design that offers a panoramic see-through view with high-resolution, wide-field-of-view imagery, while maintaining full color capability and low power consumption, due to limitations in waveguide optics that constrain the field of view and digital resolution.
Innovation Solution
The use of Substrate Guided Optics (SGO) combined with Switchable Bragg Gratings (SBGs) in a multilayer waveguide device, where SBGs are configured to extract light from both directions and operate in passive mode, allowing for thinner layers and efficient image coupling, thereby expanding the field of view and resolution without the need for tessellating gratings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional refractive optics are used to provide see-through display, then transparency is maintained, but field of view and digital resolution are limited
Solution Approach 1:
The display system is segmented into multiple waveguide layers, each responsible for specific angular intervals of the field of view. This allows the system to cover a wide total field of view while maintaining transparency, as each layer can be optimized for its specific angular range without compromising the see-through capability.
Solution Approach 2:
The patent transitions from conventional two-dimensional display architecture to a three-dimensional multilayer waveguide structure. By stacking multiple waveguide layers with different angular specifications, the system expands the field of view in the angular dimension while preserving transparency in the optical path.
2Measurement precision
If high magnification optics are used to achieve high-resolution imagery, then digital resolution is improved, but device size and weight increase
Solution Approach 1:
The patent replaces traditional mechanical optical magnification systems with a waveguide-based optical field expansion approach. Instead of using large-diameter optics and high magnification, the system uses multiple waveguide layers with specific grating configurations to achieve high-resolution imagery across a wide field of view, significantly reducing device weight.
3Adaptability or versatility
If multiple gratings are stacked to expand field of view, then field of view is improved, but device complexity and thickness increase
Solution Approach 1:
Each waveguide layer is designed to serve multiple functions: it provides structural support, guides light through total internal reflection, and contains grating structures for angular separation. This multi-functionality allows the system to achieve wide field of view without proportionally increasing complexity, as each layer is a self-contained functional unit.
Solution Approach 2:
The patent employs switchable Bragg gratings that can dynamically control light extraction at different angular intervals. This dynamic capability allows the system to expand or contract the effective field of view as needed, providing adaptability without permanently increasing device complexity or thickness.
4Adaptability or versatility
If switchable Bragg gratings are used to control light extraction, then field of view and resolution are expanded, but manufacturing complexity increases
Solution Approach 1:
The patent achieves wide field of view and high resolution by varying the grating period and orientation parameters across different waveguide layers. By systematically adjusting these parameters rather than using complex switchable mechanisms, the system maintains ease of manufacture while achieving the desired optical performance.
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 approach enables a compact, lightweight display with a wide field of view and high digital resolution, reducing thickness and complexity, while maintaining transparency and color gamut, and minimizing issues like illumination ripple and electrode scatter.
Implementation Method 1
The first optical substrate comprises at least one waveguide layer configured to propagate light in a first direction, wherein the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction
Implementation Method 2
the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction
Implementation Method 3
The use of Substrate Guided Optics (SGO) combined with Switchable Bragg Gratings (SBGs) in a multilayer waveguide device, where SBGs are configured to extract light from both directions and operate in passive mode
Data Source
AI summary
One embodiment provides an apparatus for displaying an image comprising: a first optical substrate comprising at least one waveguide layer configured to propagate light in a first direction, wherein the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction; and a second optical substrate comprising at least one waveguide layer configured to propagate the light in a second direction, wherein the at least one waveguide layer of the second optical substrate comprises at least one grating lamina configured to extract light from the second substrate along the second direction; wherein the at least one grating lamina of at least one of the first and second optical substrates comprises an SBG in a passive mode.