Transparent Circuit Boards for Eye-Tracking in AR Headsets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional eye-tracking systems in artificial reality head-mounted displays face challenges due to eyelids and eyelashes blocking light sources and reflections, leading to inconsistent tracking performance when the user looks in different directions or shifts their gaze.
Innovation Solution
The integration of transparent circuit boards with stacked conductive traces and electrical components, such as vertical-cavity surface-emitting lasers, within ophthalmic lenses to provide in-field illumination for eye-tracking systems, ensuring consistent light delivery and improved tracking accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light sources and cameras are mounted around the periphery of the frame, then the eye-tracking system can detect light reflections, but eyelids and eyelashes block the light and reflections leading to inconsistent tracking performance
Solution Approach 1:
The patent moves the light sources from the periphery of the frame to the optical element itself, specifically positioning them at the optical axis or near the pupil center. This dimensional relocation from external frame mounting to integrated optical element mounting places the light sources in a position that is not obstructed by eyelids and eyelashes, thereby resolving the light blockage issue while maintaining reliable tracking performance across all gaze directions.
2Weight of moving object
If conventional wire-bonding methods are used to connect electrical components, then electrical connections are established, but the system becomes thicker and heavier
Solution Approach 1:
The patent extracts and eliminates the wire-bonding structure from the eye-tracking system by directly mounting electrical components (such as VCSELs and cameras) onto the optical element or circuit board. This removal of the intermediate wire-bonding layer reduces both the weight and thickness of the system while maintaining all necessary electrical connections, directly addressing the contradiction between system weight and connection complexity.
Solution Approach 2:
The patent merges the electrical component mounting directly with the optical element or circuit board structure, eliminating the need for separate wire-bonding interconnects. By integrating the electrical components directly onto the substrate, the system achieves reduced weight and simplified structure while maintaining functional connectivity, effectively resolving the contradiction between weight reduction and connection complexity.
3Reliability
If light sources are positioned away from the optical axis, then manufacturing is easier, but light delivery to the eye becomes inconsistent when the user looks in different directions
Solution Approach 1:
The patent repositions the light sources from peripheral locations to positions at or near the optical axis, specifically at the pupil center or close to it. This dimensional repositioning ensures that light rays travel through the center of the pupil regardless of the user's gaze direction, maintaining consistent light delivery while the manufacturing process remains feasible through precise positioning techniques during assembly.
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 enhances eye-tracking accuracy by maintaining light delivery and reducing the need for wire-bonding, resulting in thinner, lighter, and more effective eye-tracking systems that can accurately detect user gaze direction across various orientations.
Implementation Method 1
the electrical component may be a vertical-cavity surface-emitting laser
Implementation Method 2
a transparent encapsulation layer coupled to the transparent substrate and encapsulating the electrical component
Implementation Method 3
a first conductive trace coupled to the transparent substrate, and an electrical component having a bottom surface facing the transparent substrate
Data Source
AI summary
The disclosed transparent circuit board may include a transparent substrate, a first conductive trace coupled to the transparent substrate, and an electrical component having a bottom surface facing the transparent substrate and a top surface facing away from the transparent substrate. The bottom surface may include a first electrical contact coupled to the first conductive trace, and the top surface may include a second electrical contact. The transparent circuit board may also include a second conductive trace electrically connected to the second electrical contact and a transparent encapsulation layer coupled to the transparent substrate and encapsulating the electrical component. Various other ophthalmic devices, systems, and methods are also disclosed.