Integrated Eyepiece Polarizer for AR Ghost Image Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing augmented reality systems suffer from artifacts caused by light from sources other than the projector being coupled into the eyepiece, which adversely impact viewer experience.
Innovation Solution
Integration of optical elements such as a polarizer, waveplate, and cosmetic lens with the eyepiece to control polarization, reducing the coupling efficiency of unwanted light and implementing dynamic attenuation and light recycling to enhance system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light from overhead lights near the viewer is coupled into the eyepiece, then the viewer can see ambient light, but artifacts are created that adversely impact viewer experience
Solution Approach 1:
The patent changes the polarization state parameter of light using waveplates (quarter-wave and half-wave) and polarizers. By converting linearly polarized light to circularly polarized light and back, the system creates polarization-dependent coupling that allows ambient light to be selectively blocked while maintaining visibility, thus resolving the contradiction between seeing ambient light and avoiding artifacts
Solution Approach 2:
The patent introduces polarizing beam splitters and polarizers as intermediary optical elements between the ambient light source and the eyepiece. These intermediaries selectively transmit or block light based on polarization state, allowing the system to filter out artifact-causing light while preserving useful ambient light visibility for the viewer
2Object-generated harmful factors
If a polarizer is integrated with the eyepiece to control polarization, then artifact production is decreased, but device complexity increases
Solution Approach 1:
The patent merges multiple optical functions (polarization control, beam splitting, light recycling) into a single integrated eyepiece assembly. By combining the polarizer, waveplates, and cosmetic lens into one unified structure, the system reduces the number of separate components and mounting interfaces, thereby managing device complexity while maintaining artifact reduction capabilities
Solution Approach 2:
The integrated eyepiece performs multiple functions simultaneously: it acts as a polarizer, a beam splitter, a light recycler, and a cosmetic element. This multi-functionality reduces the need for separate dedicated components, effectively managing complexity by having one component serve multiple purposes in the optical path
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
Reduces unwanted artifacts and improves viewer experience by minimizing ghost images and increasing image brightness while enhancing privacy and reducing light emission towards the outside world.
Implementation Method 1
optical elements, namely, a polarizer, a waveplate, and a cosmetic lens, which is curved, are integrated with an eyepiece. The integration of these optical elements with the eyepiece can result in low levels of artifact production as polarization control is utilized to decrease the coupling efficiency of light from sources other than the projector.
Implementation Method 2
optical elements, namely, a polarizer, a waveplate, and a cosmetic lens, which is curved, are integrated with an eyepiece
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An eyepiece unit for projecting an image to an eye of a viewer includes an eyepiece having a world side and a viewer side opposite the world side. The eyepiece unit also includes a polarizer disposed adjacent the world side of the eyepiece. In an example, the polarizer comprises a wire grid polarizer. In some embodiments, the wire grid polarizer is operable to transmit p-polarized light and reflect s-polarized light. In some embodiments, the polarizer can include an absorptive polarizer.