Scanning Fiber Drive Frequency Sweeping for Distortion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing scanning fiber devices face issues with image distortion and oversampling in the center portions of scan patterns due to operation at or near the resonant frequency of the cantilevered optical fiber, leading to phase sensitivity and environmental condition-induced distortions.
Innovation Solution
Actuating the cantilevered optical fiber with variable frequency drive signals that are displaced from the resonant frequency and varied over time to control displacement and scan pattern, reducing oversampling and phase sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the cantilevered optical fiber is vibrated at or near its resonant frequency, then the fiber achieves sufficient displacement for scanning, but image distortion and oversampling occur in the center portions of scan patterns
Solution Approach 1:
The patent applies dynamics by continuously varying the drive signal frequency over time rather than using a fixed resonant frequency. The frequency is modulated to sweep through a range that includes but is not limited to the resonant frequency, transforming the static resonant operation into a dynamic frequency-sweeping operation that eliminates stationary phase errors and oversampling artifacts
Solution Approach 2:
The patent changes the frequency parameter of the drive signal dynamically. By varying the frequency as a time-dependent parameter rather than holding it constant at resonance, the system achieves the necessary fiber displacement while avoiding the persistent phase sensitivity and oversampling problems that occur at fixed resonant frequencies
2Productivity
If the cantilevered optical fiber is vibrated at resonant frequency, then scanning efficiency is improved, but phase sensitivity to environmental conditions increases causing distortions
Solution Approach 1:
The system transitions from static resonant operation to dynamic frequency sweeping. By continuously changing the drive frequency over time, the fiber is never held at a single resonant frequency where phase sensitivity to environmental conditions would cause instability. The dynamic operation averages out phase errors and eliminates their cumulative effect
Solution Approach 2:
The patent employs periodic frequency sweeping where the drive signal frequency is modulated in a periodic manner. This periodic variation in frequency ensures that the fiber experiences a repeating pattern of excitation that is insensitive to gradual environmental drifts, maintaining phase stability while preserving scanning efficiency
3Device complexity
If constant frequency drive signals are used, then the scanning operation is simple, but oversampling occurs in the center portions of spiral scan patterns
Solution Approach 1:
The patent changes the frequency parameter from a constant value to a time-varying function. By making frequency a variable parameter that changes over time according to a controlled pattern, the system achieves uniform sampling distribution across the scan pattern while maintaining relatively simple control electronics that can generate frequency-modulated signals
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 approach enhances image quality by evenly distributing sampling points across the scan pattern, reducing distortions and improving image clarity.
Implementation Method 1
The cantilevered optical fiber is commonly vibrated at or very near its mechanical or vibratory resonant frequency
Implementation Method 2
The cantilevered optical fiber is commonly vibrated at or very near its mechanical or vibratory resonant frequency
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Methods of moving or vibrating cantilevered optical fibers of scanning fiber devices are disclosed. In one aspect, a method may include vibrating the cantilevered optical fiber at an initial frequency that is substantially displaced from a resonant frequency of the cantilevered optical fiber. Then, the frequency of vibration of the cantilevered optical fiber may be changed over a period of time toward the resonant frequency. Light may be directed through an end of the cantilevered optical fiber while the cantilevered optical fiber is vibrated.