Reflective Facet Waveguide for Multi-Source Image Combining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional eyewear displays with reflective facets face challenges in balancing the need for users to see through the facets while increasing display brightness and uniformity, often compromising image quality due to limited image display efficiency and increased system volume.
Innovation Solution
A waveguide incorporating a plurality of reflective facets that selectively reflect or transmit light based on optical characteristics such as wavelength ranges or polarization states, allowing light from multiple image sources to be combined within the waveguide, enhancing brightness and uniformity without increasing the system's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional eyewear displays use reflective facets to increase display brightness, then image brightness is improved, but the system volume increases and image quality deteriorates
Solution Approach 1:
The patent combines multiple image sources (first image source and second image source) within a single waveguide substrate. The first and second sets of reflective facets are integrated into the same waveguide, allowing light from both sources to be combined and guided through the same optical path, thereby increasing brightness without proportionally increasing system volume.
Solution Approach 2:
The patent implements a nested structure where the first and second sets of reflective facets are positioned within the same waveguide substrate. The facets are arranged such that light from the first image source and second image source are both coupled into and guided by the same waveguide, creating a compact nested configuration that maximizes space utilization.
2Illumination intensity
If conventional eyewear displays use reflective facets to increase display brightness, then image brightness is improved, but image quality deteriorates
Solution Approach 1:
The patent applies different optical characteristics to different sets of reflective facets. The first set of reflective facets has specific reflective properties optimized for the first image source, while the second set has different reflective properties optimized for the second image source. This local differentiation allows each facet set to efficiently guide its corresponding light source while maintaining overall image quality.
3Illumination intensity
If conventional eyewear displays use multiple image sources to increase brightness, then display brightness is improved, but device complexity increases
Solution Approach 1:
The waveguide substrate serves multiple functions: it guides light from the first image source through the first set of reflective facets, simultaneously guides light from the second image source through the second set of reflective facets, and combines both light paths within the same structure. This multi-functionality reduces the need for separate waveguide structures for each image source, thereby reducing overall device 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 increases the brightness and uniformity of images displayed in eyewear displays while maintaining a compact form factor by efficiently combining light from multiple sources within the waveguide, improving the overall image quality.
Implementation Method 1
Once the light beams have been coupled into the waveguide, the light beams are 'guided' through the substrate, typically by multiple instances of total internal reflection (TIR)
Implementation Method 2
each reflective facet of the plurality of reflective facets to selectively reflect light having a first optical characteristic of a plurality of optical characteristics
Implementation Method 3
the plurality of optical characteristics are different wavelength ranges, and wherein the one or more reflective facets of the plurality of reflective facets comprises a dichroic mirror coating
Implementation Method 4
a first facet of the plurality of reflective facets comprises a mirror to reflect light having a first polarization state and wherein a second facet of the plurality of reflective facets comprises a polarization beam splitter
Data Source
AI summary
A waveguide for an eyewear display includes a set of reflective incoupler facets to incouple light and/or a set of reflective exit pupil expander (EPE) facets to expand the incoupled light in a first direction. The reflective incoupler facets are each designed to incouple light of a particular optical characteristic such as a particular wavelength range or polarization state and transmit light of other optical characteristics incoupled at other ones of the reflective incoupler facets. The reflective EPE facets receive light from multiple sources (e.g., multiple incouplers). In some configurations, each of the reflective EPE facets is designed to reflect or transmit light incident thereon to direct light to an outcoupler in a more uniform manner.