Beam Splitter Coatings for AR Waveguide Color Fidelity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reflective augmented reality waveguides suffer from low image quality due to issues such as low contrast, insufficient color fidelity, and reduced sharpness.
Innovation Solution
A beam splitter with a substrate and coatings designed to control color shift and phase difference for light beams within specific angles and wavelengths, ensuring minimal differences in CIE x and y coordinates for transmitted and reflected light, using materials like glass ceramics and dielectric layers to optimize image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional beam splitters are used in reflective augmented reality waveguides, then the device structure is simple, but the image quality deteriorates due to low contrast, insufficient color fidelity and reduced sharpness
Solution Approach 1:
The beam splitter is divided into multiple functional layers: a substrate and at least one coating layer with specific optical properties. This segmentation allows each layer to be optimized independently for its specific function (reflection, transmission, phase control), thereby improving overall image quality without creating a monolithic complex structure
Solution Approach 2:
The beam splitter uses composite material structures combining substrate materials (such as glass ceramics) with coating materials (such as dielectric layers). This composite approach enables precise control of optical properties including color shift and phase difference, achieving superior image quality while maintaining structural simplicity
2Manufacturing precision
If the beam splitter controls color shift for multiple wavelengths and angles, then color fidelity improves, but the design complexity increases
Solution Approach 1:
The coating is designed with spatially varying optical properties to address different wavelengths and angles of incidence locally. The coating structure is optimized for specific wavelength ranges (e.g., 400-730 nm) and angle ranges (e.g., 15°-75°) rather than attempting uniform performance across all conditions, improving color fidelity while managing design complexity
Solution Approach 2:
The beam splitter design adjusts key parameters including coating thickness, refractive index, and layer composition to control color shift and phase difference. By systematically varying these parameters within specific ranges, the design achieves minimal color shift (Δx < 0.05, Δy < 0.05) across multiple wavelengths and angles without requiring excessively complex structures
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 significantly improves image quality in augmented reality waveguides by minimizing color shift and phase differences, resulting in higher contrast and sharper images.
Implementation Method 1
at least one coating arranged on at least one main surface of the substrate... which is partly transmitted through the beam splitter and partly reflected by the beam splitter
Implementation Method 2
said light beam after transmitting through the beam splitter has a difference between the CIE x coordinates... and the CIE x coordinates of the light beam after transmitting through the beam splitter
Implementation Method 3
additional controlling the phase of the transmitted light beam allows to significantly improve the quality of the image
Data Source
AI summary
The present invention relates to a beam splitter and a method of manufacturing such a beam splitter. The present invention also relates to a stack comprising two or more such beam splitters.