Active Ripple Cancellation for MEMS Mirror Distortion
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Solution Overview
Problem
Wearable electronic eyewear devices with optical systems are sensitive to vibrations from internal and external disturbances, leading to distortion in display output, particularly when exposed to high-volume audio sources.
Innovation Solution
The implementation of an active ripple cancellation (ARC) system that determines when incoming sound frequencies exceed a defined threshold corresponding to resonant frequencies of the optical reflector, and generates sound waves to destructively interfere with these frequencies, thereby mitigating distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-volume audio sources are used, then audio output quality is improved, but distortion patterns appear in the display system due to resonant vibrations of the optical reflector
Solution Approach 1:
The system proactively generates anti-phase sound waves to counteract resonant vibrations before they cause significant distortion. The active ripple cancellation system detects incoming sound frequencies, identifies resonant frequencies of the optical reflector, and preemptively generates destructive interference patterns to neutralize the harmful vibrations, thereby maintaining display quality even during high-volume audio playback
Solution Approach 2:
The system converts the harmful resonant vibrations into beneficial anti-phase vibrations through destructive interference. By generating sound waves that are 180 degrees out of phase with the resonant frequencies, the system transforms the problematic vibrational energy into a canceling force, effectively using the same acoustic mechanism that causes the problem to solve it
2Productivity
If resonant frequency vibrations are allowed to occur, then audio playback is maintained, but display stability deteriorates due to harmonic motions of the optical reflector
Solution Approach 1:
The system implements a closed-loop feedback mechanism where microphones continuously monitor sound frequencies, the controller identifies resonant frequencies affecting the optical reflector, and speakers generate corrective anti-phase sound waves. This real-time feedback loop maintains display stability by dynamically counteracting vibrations while preserving audio playback continuity, as the system adapts to changing acoustic conditions without interrupting music or speech
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 ARC system effectively reduces or eliminates distortion patterns in the display system by using destructive interference to counteract the undesirable harmonic motions caused by high-volume audio sources, thereby improving the stability and clarity of the display output.
Implementation Method 1
generating sound waves to destructively interfere with at least one frequency component of the one or more frequency components
Implementation Method 2
one or more frequency components of an incoming sound that correspond to one or more resonant frequencies of an optical reflector
Data Source
AI summary
Systems, devices, and methods are described for mitigating or eliminating distortion patterns (such as those caused by one or more high-volume audio sources) in a display system such as a laser projection system. Frequency components of an incoming sound that correspond to one or more resonant frequencies of an optical reflector of the display system are determined to exceed a defined volume threshold. Responsive to that determination, a magnitude and phase of one or more harmonic motions of the optical reflector are measured. Sound waves are generated to destructively interfere with at least one frequency component corresponding to the resonant frequencies of the optical reflector.