Waveguide Holographic Optics for Comfortable See-Through Viewing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Look-through displays cause user discomfort and eye strain due to the challenge of focusing on real objects and displayed imagery simultaneously, particularly when the user desires to view real objects and overlaid imagery at different focal distances.
Innovation Solution
Incorporating an expansion waveguide and an optically powered element with holographic components to expand the exit pupil and create a virtual image plane, allowing users to perceive imagery at a specific distance behind the waveguide, reducing eye strain and discomfort by enabling simultaneous focus on both real and overlaid imagery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If collimated light is output towards a semi-reflective element in a look-through display, then the displayed imagery is visible to the user, but the user experiences eye strain and discomfort when trying to focus on real objects simultaneously
Solution Approach 1:
The patent introduces a focal adjustment mechanism that adds a new dimension of control to the optical system. By enabling dynamic adjustment of the focal plane position along the optical axis, the system allows the virtual image to be focused at different depths, creating a multi-planar viewing experience that accommodates both the displayed imagery and real-world objects at varying distances.
Solution Approach 2:
The optical system transitions from a static focal configuration to a dynamic one where the focal plane can be adjusted in real-time. This dynamic capability allows the system to adapt to different viewing conditions, enabling users to switch focus between the virtual displayed content and real-world objects without experiencing eye strain from fixed focal constraints.
2Measurement precision
If the user focuses on real objects in the view, then the real scenery is clearly visible, but the displayed symbology/imagery becomes difficult to observe
Solution Approach 1:
The patent creates depth separation by enabling the virtual image to be positioned at adjustable focal planes that can be distinct from the real-world object planes. This dimensional separation in depth space allows users to focus on real objects at one focal distance while the displayed symbology remains visible at a different focal distance, eliminating the need to choose between the two.
Solution Approach 2:
The optical system segments the viewing space into multiple focal planes, allowing different content (real objects and displayed imagery) to be positioned at different depths. This segmentation enables independent focusing on each plane, so users can clearly see real objects while simultaneously observing displayed symbology without one obscuring the other.
3Illumination intensity
If the virtual image plane is positioned close to the waveguide, then the displayed imagery is prominent, but the user cannot comfortably view both the imagery and real objects
Solution Approach 1:
The system employs dynamic focal plane adjustment that allows users to move the virtual image plane to optimal positions based on viewing conditions. When prominence is needed, the virtual image can be positioned closer to the waveguide; when comfortable dual viewing is needed, the focal plane can be adjusted to create appropriate depth separation, providing flexibility to optimize for different operational requirements.
Solution Approach 2:
The patent changes the focal distance parameter of the virtual image to optimize viewing comfort. By adjusting this key optical parameter, the system can position the virtual image at different distances from the waveguide, allowing users to find the optimal balance between imagery prominence and comfortable co-viewing with real objects.
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 effectively reduces eye strain and discomfort by allowing users to comfortably view real and overlaid imagery at different focal distances, enhancing the user experience.
Implementation Method 1
an expansion waveguide (210) configured to receive light and expand the light in at least one dimension
Implementation Method 2
an optically powered element (230) comprising holographic components to provide the optical power... adds an angular offset to the collimated light, causing the collimated light to diverge and form a virtual image plane (240)
Implementation Method 3
an optically powered element (230) comprising holographic components to provide the optical power
Data Source
AI summary
In various embodiments, an optical system to present an image to an eye of a user is disclosed. The system comprises a waveguide configured to output collimated light towards an optically powered element comprising at least one holographic component to generate optical power. The optically powered element is configured to receive the output collimated light from the waveguide and direct the received light towards the eye of the user and impart an angular offset on the directed light such that the directed light forms a virtual image plane.