Pupil Replicator and Turning Layer for Two-Dimensional Field of View Expansion
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Solution Overview
Problem
Existing image projection systems face challenges in increasing the range of angles of light rays that can propagate through an eye's pupil, limiting the field of view and requiring precise eye positioning.
Innovation Solution
A system comprising a pupil replicator and a turning layer, which expands the range of angles of light rays by replicating the input light field and aligning the directions of expansion in the replicators, allowing for two-dimensional pupil expansion and improved field of view.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a conventional single pupil expander is used, then the viewing area is limited in one dimension, but the system remains simple and compact
Solution Approach 1:
The patent divides the pupil expansion function into two separate one-dimensional pupil expanders instead of using a single two-dimensional expander. Each expander handles expansion in one dimension (horizontal or vertical), reducing the complexity of individual components while achieving comprehensive two-dimensional viewing area expansion when combined
Solution Approach 2:
The patent transitions from single-dimensional to two-dimensional pupil expansion by adding a second pupil expander oriented perpendicular to the first. This dimensional approach multiplies the viewing area in both horizontal and vertical directions, creating a comprehensive expansion effect that neither single-dimension expander could achieve alone
2Area of moving object
If two one-dimensional pupil expanders are used for two-dimensional expansion, then the viewing area increases in both dimensions, but the optical system becomes more complex and bulky
Solution Approach 1:
The patent positions the second one-dimensional pupil expander such that it processes the output light from the first expander in a nested configuration. The light path from the first expander becomes the input to the second expander, allowing sequential processing in different dimensions without requiring excessive spacing between components
Solution Approach 2:
The patent introduces an optical element with a turning layer as an intermediary between the two pupil expanders. This turning layer redirects the light path at approximately 45 degrees, enabling compact arrangement of the expanders and reducing the overall system volume while maintaining proper optical alignment
3Adaptability or versatility
If the range of light ray angles is increased to expand field of view, then eye movement freedom improves, but precise eye positioning requirements become more complex
Solution Approach 1:
The patent changes the angular parameters of the light ray bundles by using multiple pupil expanders that replicate and redirect light at different angles. This creates a broader distribution of light ray angles that reach the viewer's eye, expanding the field of view and allowing greater eye movement freedom without requiring precise eye positioning
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 system effectively increases the viewing area, enabling eye movement while maintaining a clear image, and reduces the complexity of the optical system by using a less bulky turning layer.
Implementation Method 1
Each waveguide pupil expander is arranged to replicate the input light field to expand the range of angles of light rays in one dimension each
Implementation Method 2
an optical element comprising a turning layer, which changes the direction of light rays to align the directions of expansion in the first and second pupil expanders
Data Source
AI summary
A system comprising a first replicator, a second replicator and an optical element is described. The first replicator is arranged to receive a diffracted light field and replicate the diffracted light field in a first direction. The second replicator is arranged to receive output light from the first replicator and replicate the diffracted light field in a second direction, the second direction substantially perpendicular to the first direction. The optical element comprises a turning layer. The optical element is arranged to optically-couple output light from the first replicator to an input of the second replicator. The turning layer is arranged to turn a ray direction of output light from the first replicator.