Optical Scanning Apparatus Resonance Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical scanning apparatuses face issues with detecting ringing frequencies during scanning, which disrupts image drawing due to the need to stop scanning during frequency detection and require complex calculations, increasing processing costs and time.
Innovation Solution
An optical scanning apparatus with a control circuit that includes an angular velocity calculator, target angular velocity calculator, resonance frequency detector, drive waveform generator, and unnecessary vibration controller, allowing for the detection of ringing frequencies during scanning by optimizing the drive signal using a notch filter, enabling continuous image drawing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency sweep detection method is used to detect ringing frequency, then detection accuracy is improved, but image drawing must be stopped during detection causing loss of productivity
Solution Approach 1:
The patent enables continuous image drawing during ringing frequency detection by using the existing sawtooth wave drive signal instead of stopping to perform frequency sweep detection. The resonance frequency detector analyzes the mirror's angular velocity waveform during normal operation, allowing both image drawing and frequency detection to occur simultaneously without interrupting productivity.
Solution Approach 2:
The system uses its own operational data (angular velocity waveform during normal sawtooth drive) to detect ringing frequency, eliminating the need for separate detection procedures. The resonance frequency detector leverages the mirror's natural response during regular operation to identify resonance frequencies, making the detection process self-service and non-intrusive to the main function.
2Measurement precision
If frequency sweep and FFT analysis are used to detect ringing, then detection precision is improved, but processing time and computational complexity increase
Solution Approach 1:
The patent replaces complex computational methods (FFT analysis of frequency sweep data) with a simpler detection approach. The resonance frequency detector identifies ringing frequency by analyzing the angular velocity waveform characteristics during normal operation, avoiding the need for computationally intensive FFT calculations and frequency sweep procedures, thereby reducing processing time while maintaining detection accuracy.
3Ease of operation
If sawtooth wave drive signal is used for compulsive driver, then scanning function is achieved, but resonance vibration causes unnecessary ringing
Solution Approach 1:
The patent implements a feedback mechanism where the resonance frequency detector continuously monitors the mirror's angular velocity to identify resonance frequencies, and this information is fed back to the drive waveform generator. The drive waveform generator then adjusts the sawtooth wave signal to eliminate frequency components that cause ringing, suppressing the harmful vibrations while maintaining the scanning function.
Solution Approach 2:
The patent converts the harmful resonance vibration into a useful detection signal. The ringing caused by the sawtooth drive signal provides information about the mirror's resonance frequency, which is detected and used to optimize the drive waveform. The harmful vibration becomes the basis for identifying and eliminating the problematic frequency components.
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
Enables the detection of ringing frequencies during scanning without interrupting image drawing, reducing processing costs and time, and improving the efficiency of the scanning process.
Implementation Method 1
a compulsive driver part configured to swing the mirror about a second axis parallel with a different direction different from the one direction by providing piezoelectric elements with a voltage
Implementation Method 2
a resonance driver part configured to swing the mirror about a first axis parallel with the one direction by applying resonance vibration to the support beams
Data Source
AI summary
A control circuit includes: an angular velocity calculator calculating an angular velocity of a mirror based on an angle of the mirror; a target angular velocity calculator calculating a target value of the angular velocity; a resonance frequency detector detecting a frequency of vibration of the mirror using the angular velocity and target value; a drive waveform generator generating a drive signal having sawtooth waveform; and an unnecessary vibration controller optimizing the drive signal to reduce an unnecessary vibration of the mirror based on the frequency of vibration of the mirror and providing piezoelectric elements with voltage according to the optimized drive signal. The resonance frequency detector detects the frequency of vibration of the mirror using a waveform and the target value of the angular velocity of the mirror during a duration in which the drive signal is transmitted to the unnecessary vibration controller from the drive waveform generator.