Layered Glass Waveguide Pupil Expander Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing waveguide pupil expanders in holographic projection systems, such as head-up displays, are prone to breakage due to mechanical stress, leading to structural and functional integrity issues, which can compromise image quality and safety.
Innovation Solution
A layered glass structure is implemented in the waveguide pupil expander, comprising a glass layer laminated with a polymer-based layer, which maintains the structural and functional integrity of the waveguide even if the glass layer breaks, by ensuring that the reflective surfaces remain parallel and that light continues to be guided effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a glass waveguide is used in a head-up display, then the optical performance and image quality are improved, but the structural integrity and safety are worsened due to breakage risk
Solution Approach 1:
The waveguide structure is divided into multiple layers: a glass waveguide layer for optical performance and a polymer protective layer for structural integrity. This segmentation allows each layer to fulfill its specific function while working together as a unified structure that maintains both optical quality and safety.
Solution Approach 2:
The invention uses a composite structure combining glass and polymer materials. The glass layer provides superior optical properties for image quality, while the polymer layer provides mechanical strength and shatter resistance. This composite approach resolves the contradiction between optical performance and structural safety.
2Reliability
If the glass layer in the waveguide breaks, then the structural integrity deteriorates, but the polymer layer maintains the functional integrity by keeping reflective surfaces parallel
Solution Approach 1:
The polymer protective layer is applied beforehand to the glass waveguide to cushion and contain potential breakage. This pre-applied protective layer ensures that if the glass breaks, the fragments remain contained and the reflective surfaces maintain their parallel alignment, preserving functional integrity.
Solution Approach 2:
The polymer layer acts as an intermediary between the glass waveguide and the external environment. It mediates the stress and impact forces, preventing direct transmission to the glass structure and maintaining the parallelism of reflective surfaces even when the glass layer is compromised.
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 layered glass structure effectively maintains the integrity of the waveguide pupil expander upon breakage, ensuring continued functionality and safety by preventing the scattering of glass fragments and maintaining image quality.
Implementation Method 1
The pair of parallel reflective surfaces is arranged to guide the spatially-modulated light from the input port to the output port by a series of internal reflections
Implementation Method 2
A first reflective surface of the pair of parallel reflective surfaces is partially transmissive and partially reflective
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A holographic system comprises a display device and a waveguide pupil expander. The display device is arranged to display a hologram and to output spatially modulated light in accordance with the hologram. The waveguide pupil expander is configured to receive spatially modulated light from the display device at the input port thereof and to expand the viewing window of the system. The waveguide pupil expander comprises first and second substantially planar reflective surfaces arranged in parallel having an optically transparent material therebetween. The first reflective surface is fully reflective and the second reflective surface is partially reflective such that light is guided from the input port to an output port at the second reflective surface by a series of internal reflections. The optically transparent material is formed by a layered glass structure arranged to maintain the integrity of the waveguide in the event of breakage of glass.