Head-Mounted Optical Modules With Self-Mixing Alignment Feedback
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Solution Overview
Problem
Head-mounted devices experience misalignment of optical components due to stress events such as drops, affecting their operational performance.
Innovation Solution
Incorporation of optical self-mixing sensors to accurately measure component positions and adjust actuators to compensate for changes, ensuring alignment through real-time feedback and potential digital or physical adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical components are fixed rigidly in the head-mounted device, then manufacturing and assembly are simpler, but misalignment occurs due to stress events such as drops
Solution Approach 1:
The system performs preliminary measurement of optical component positions using optical self-mixing sensors before stress events occur. The actuators are pre-configured to adjust components based on measured positions, enabling rapid compensation when stress events happen without requiring complex real-time sensing during the event itself.
Solution Approach 2:
The patent implements a feedback loop where optical self-mixing sensors continuously measure the positions of optical components (lenses, displays, cameras), and actuators adjust the components based on measured deviations from desired positions. This closed-loop feedback system maintains alignment reliability while using relatively simple sensor-actuator pairs rather than complex active control systems.
2Measurement precision
If optical self-mixing sensors are added to measure component positions, then alignment precision is improved, but device complexity increases
Solution Approach 1:
The optical self-mixing sensors measure positions of optical components using light reflected from the components themselves, without requiring external measurement systems or complex sensor assemblies. The sensors utilize the optical path already present in the device (light passing through lenses and displays) to measure component positions, making the measurement system self-contained and minimizing additional complexity.
3Stability of the object's composition
If actuators are used to adjust optical components in real-time, then operational stability under stress is improved, but energy consumption increases
Solution Approach 1:
The system performs alignment measurements and adjustments periodically rather than continuously. The optical self-mixing sensors measure component positions at scheduled intervals, and actuators make adjustments only when deviations exceed predetermined thresholds. This periodic operation significantly reduces energy consumption compared to continuous real-time adjustment while maintaining alignment stability under stress conditions.
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
Maintains optical component alignment within tight tolerances, enhancing the device's operational stability and image quality under stress conditions.
Implementation Method 1
The optical self-mixing sensor is configured to emit light that reflects from the lens surface back to the optical self-mixing sensor
Data Source
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AI summary
A head-mounted device may have a head-mounted housing and optical components supported by the head-mounted housing. The optical components may include cameras, movable optical modules, and other components. Each optical module may include a display that displays an image and a lens that provides the image to a corresponding eye box. Optical self-mixing sensors may be included in the optical modules and other portions of the head-mounted device to measure changes in optical component position. In response to detecting a change in optical component position, actuators in the device may be adjusted to move the optical components or other action may be taken to compensate for the change.