Holographic Waveguide Display for Wide Field-of-View and Aberration-Free Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current see-through head-mounted displays suffer from poor light transmission, limited field-of-view, and high cost due to complex optics and color dispersion issues, limiting their application in fields like construction, sports, and military where a wide, aberration-free view is necessary.
Innovation Solution
A substrate-guided wave-based holographic see-through display using a thin transparent waveguide with holographic elements for in-coupling and out-coupling light, providing a wide field-of-view and long eye relief, and capable of being formed on a curved substrate for compact optics, achieving high transparency and reduced optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single hologram is used for see-through image creation, then the structure is simplified, but color dispersion occurs resulting in poor image quality
Solution Approach 1:
The patent divides the single hologram into two separate holograms (first hologram and second hologram) positioned at different locations on the waveguide. This segmentation allows each hologram to be optimized for specific functions: the first hologram couples light into the waveguide while the second hologram couples it out, thereby eliminating color dispersion issues that plague single-hologram designs.
2Device complexity
If opaque head-mounted displays are used, then the display structure is simplified, but the user cannot see through to the real world
Solution Approach 1:
The patent employs a transparent waveguide with holographic elements that are transparent to visible light. The holograms are designed to manipulate specific wavelengths or angles of light while remaining transparent to other wavelengths, allowing the display to switch between opaque (when displaying) and transparent (when not displaying) states, thereby enabling see-through capability.
3Adaptability or versatility
If partially reflective combiner elements are used, then see-through capability is achieved, but light transmission is poor resulting in dim view and decreased brightness
Solution Approach 1:
The patent replaces the traditional partially reflective combiner (a mechanical optical element) with a waveguide-based holographic system. The holographic elements use diffraction and total internal reflection to guide light through the waveguide, achieving see-through capability without the light loss inherent in reflective combiners. This substitution of mechanical reflection with waveguide-based light guidance dramatically improves light transmission and brightness.
4Manufacturing precision
If conventional optics are used, then image creation is achieved, but the size and weight of the display increases
Solution Approach 1:
The patent extracts and eliminates bulky conventional optical elements (lenses, mirrors, prisms) from the display system by replacing them with thin-film holographic elements deposited on a waveguide. This extraction of unnecessary components dramatically reduces the size and weight of the display while maintaining image creation capability through the holographic light guidance mechanism.
5Manufacturing precision
If complex hologram recording geometries are used, then color imagery is achieved, but fabrication cost and implementation complexity increase significantly
Solution Approach 1:
The patent changes the recording parameters of the holograms to use simple, planar geometries with standard wavelengths and angles that can be easily fabricated using conventional holographic recording techniques. By optimizing the hologram recording parameters (wavelength, angle, thickness), the patent achieves color imagery without requiring complex aspheric recording wave-fronts, thereby significantly reducing fabrication cost and implementation 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 solution offers a high-light-throughput, aberration-free virtual image with a wide field-of-view and long eye relief, enabling a highly transparent view of the outside world while reducing the number of optical elements and fabrication costs, thus enhancing usability in various applications.
Implementation Method 1
transmitting the accepted light in the form of an image along a length of the substrate by total internal reflection to a second location spaced from the first location
Implementation Method 2
A holographic lens, capable of accepting the light in the form of an image from the microdisplay, and capable of transmitting the accepted light in the form of an image
Data Source
AI summary
A holographic substrate-guided wave-based see-through display has a microdisplay, capable of emitting light in the form of an image. The microdisplay directs its output to a holographic optical element, capable of accepting the image from the microdisplay, and capable of transmitting the light. The holographic optical element couples its output to an elongate substrate, capable of accepting the light from the holographic optical element at a first location, and transmitting the light along a length of the substrate by internal reflection to a second location, the elongate substrate being capable of transmitting the accepted light from the second location. The substrate couples out what it receives to a transparent holographic optical element, capable of accepting the light transmitted from the substrate and transmitting it to a location outside of the holographic optical element as a viewable image.