Exit Pupil Expanding Light Guide for Multi-Display AR
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Solution Overview
Problem
Current head-mounted display apparatuses for virtual reality struggle to effectively combine and convey additional information alongside primary content, often limiting the ability to provide enhanced visual experiences due to limitations in display resolution and optical arrangements.
Innovation Solution
The use of an exit pupil expanding light guide arrangement that couples and expands light from multiple display arrangements, allowing for the simultaneous and enhanced delivery of primary and secondary content to the user, with the option of different display devices and resolutions, and the incorporation of polarizers and diffraction gratings for optimized light transmission and expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If multiple display arrangements are combined to provide both primary content and additional information, then the quantity of information displayed is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple display arrangements (first display arrangement for primary content, second display arrangement for additional information) into a single integrated system. The optical arrangement merges the light paths from both displays through waveguides and beam combiners, allowing simultaneous delivery of multiple information streams through a unified optical path to the user's eye.
Solution Approach 2:
The optical arrangement serves multiple functions: it guides light from the first display arrangement, simultaneously guides light from the second display arrangement, combines both light paths, and delivers them to the user. The waveguide structure and beam combiners are designed to handle multiple optical streams, making the system multi-functional rather than requiring separate independent systems.
2Measurement precision
If display resolution is increased to improve visual quality, then the manufacturing precision requirements worsen
Solution Approach 1:
The optical arrangement is segmented into distinct functional modules: first waveguide for primary content, second waveguide for additional information, beam combiners, and exit pupil expanders. Each module can be independently manufactured and aligned, then assembled into the complete system. This segmentation allows for modular manufacturing where high precision is achieved in each subsystem rather than requiring ultra-high precision across the entire system at once.
Solution Approach 2:
The patent introduces intermediary optical elements (beam combiners, waveguides with specific coupling regions) that mediate between the display arrangements and the user's eye. These intermediaries provide alignment tolerance and facilitate the integration of multiple light paths, reducing the direct alignment precision requirements between the displays and the user's pupil.
3Area of moving object
If the field of view is expanded to provide wider visual coverage, then the optical arrangement complexity increases
Solution Approach 1:
The patent employs exit pupil expanding regions that operate in the spatial dimension to broaden the effective field of view. By expanding the exit pupil in multiple dimensions (both horizontal and vertical), the system provides wider visual coverage without requiring complex lateral displacement of optical elements. The dimensionality of light propagation is utilized to achieve expanded viewing angles.
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 solution enables the expansion of light in multiple dimensions, allowing for the delivery of high-resolution primary content and secondary information, enhancing the user's experience by providing virtual and real images that are in focus and correctly aligned, while also addressing issues of motion sickness and alertness through context-sensitive color adjustments.
Implementation Method 1
an exit pupil expanding light guide arrangement comprising an in-coupling region configured to in-couple first light from a first display arrangement and second light from a second display arrangement into the exit pupil expanding light guide arrangement
Implementation Method 2
the use of an exit pupil expanding light guide arrangement that couples and expands light from multiple display arrangements
Implementation Method 3
for guiding the received light therealong to an output area thereof
Implementation Method 4
an out-coupling region configured to out-couple the first light from the first display arrangement towards a user
Implementation Method 5
for outputting from the output area the image-bearing light collimated to present a viewable image
Implementation Method 6
the incorporation of polarizers and diffraction gratings for optimized light transmission and expansion
Implementation Method 7
the incorporation of polarizers and diffraction gratings for optimized light transmission and expansion
Data Source
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AI summary
An apparatus and a method are provided. An apparatus, comprising: a first display arrangement; an exit pupil expanding light guide arrangement comprising an in-coupling region and an out-coupling region, the in-coupling region being configured to in-couple first light from the first display arrangement, and the out-coupling region being configured to out-couple the first light towards a user; and a second display arrangement arranged to transmit second light, through the exit pupil expanding light guide arrangement at the out-coupling region, towards the user.