Polarization-Selective Diffusive Combiner for Near-Eye Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable head-mounted displays for virtual reality and augmented reality applications face challenges in providing a comfortable and effective viewing experience due to bulky designs that can attenuate outside light, causing eyestrain and confusion from the interference of real-world visuals with virtual content.
Innovation Solution
The use of a polarization-selective scatterer element that allows ambient light to pass without scattering while scattering display light, combined with a projector and focusing elements, enables efficient viewing of virtual content while maintaining visibility of the outside environment by polarizing and selectively dimming ambient light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If a compact display device is used for head-mounted display, then the device size and weight are reduced, but the outside light transmission may be insufficient
Solution Approach 1:
The combiner is divided into multiple sections with different optical properties: a first region that transmits outside light and a second region that blocks outside light. This segmentation allows different parts of the combiner to perform different functions, enabling compact design while maintaining adequate outside light transmission in the first region.
Solution Approach 2:
Different regions of the combiner are assigned different optical characteristics tailored to their specific functions. The first region has high transmission quality for outside light, while the second region has blocking quality for virtual image formation. This local differentiation resolves the contradiction between compactness and light transmission.
2Illumination intensity
If the outside environment is fully visible through the display, then natural viewing is maintained, but virtual content becomes indiscernible due to visual interference
Solution Approach 1:
The combiner is segmented into a first region for outside light transmission and a second region for virtual image display. This spatial segmentation separates the optical paths for real-world viewing and virtual content, eliminating visual interference while maintaining both functions.
Solution Approach 2:
The combiner acts as an intermediary optical element that mediates between outside light and virtual display light. By using a reflective polarizer and controlling polarization states, the combiner selectively combines or separates the two light paths, preventing them from interfering with each other.
3Loss of information
If a polarizing filter is used to block outside light, then virtual content visibility is improved, but overall light transmission is reduced
Solution Approach 1:
The combiner is divided into regions with different polarizing properties. The first region uses a reflective polarizer that transmits outside light in a specific polarization state while blocking other polarization states. This selective blocking in only certain regions maintains overall light transmission while improving virtual content visibility where needed.
Solution Approach 2:
The system changes the polarization state of light as it passes through different regions of the combiner. By controlling polarization parameters rather than simply blocking all light, the system achieves selective visibility control that maintains overall transmission while enabling virtual content display.
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 configuration enhances user comfort by reducing bulkiness and minimizing visual interference, allowing for clear and immersive virtual content presentation while preserving the view of the real world.
Implementation Method 1
a polarizer for polarizing impinging ambient light to have a first polarization state
Implementation Method 2
a polarization-selective scatterer downstream of the polarizer, for receiving and propagating therethrough the ambient light polarized by the polarizer substantially without scattering, while scattering impinging display light having a second polarization state orthogonal to the first polarization state
Data Source
AI summary
A near-eye display based on a polarization-selective diffusive combiner includes a polarizer for polarizing impinging ambient light to have a first polarization state, and a polarization-selective scatterer downstream of the polarizer, for passing through the ambient light having the first polarization state substantially without scattering, while scattering impinging display light having a second polarization state orthogonal to the first polarization state. The display light at the second polarization state may be provided by a projector, the polarization-selective scatterer playing the role of a projector screen. A polarization-selective ocular lens may be disposed downstream of the polarization-selective scatterer for viewing images generated by the projector while propagating through orthogonally polarized light from outside environment.