Micromirror Resonance Tuning for Abnormal Oscillation Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing micromirror devices face challenges in suppressing abnormal oscillation, which can lead to reduced displacement angles and compromised optical scanning performance, especially when additional structural complexities are introduced to mitigate this issue.
Innovation Solution
The micromirror device incorporates a first actuator with annularly disposed piezoelectric elements and a second actuator with a meander structure, where specific resonance frequency differences are managed to suppress abnormal oscillation, ensuring stable operation and high displacement angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional structures are added to suppress abnormal oscillation, then abnormal oscillation is reduced, but device complexity increases and manufacturing stability decreases
Solution Approach 1:
The patent changes the resonance frequency parameters of the micromirror device by adjusting the size and shape of the mirror part and actuator. Specifically, it controls the difference between the resonance frequency in the driving mode and the resonance frequency in the abnormal oscillation mode to be within a specific range (50-200 Hz), thereby suppressing abnormal oscillation without adding additional structures.
2Reliability
If additional structures are added to suppress abnormal oscillation, then abnormal oscillation is reduced, but manufacturing stability decreases
Solution Approach 1:
The patent achieves abnormal oscillation suppression by optimizing existing geometric parameters (mirror part size, actuator dimensions) rather than adding new structures. This approach maintains manufacturing simplicity and stability while effectively controlling the resonance frequency difference to prevent abnormal oscillation.
3Reliability
If additional structures are added to suppress abnormal oscillation, then abnormal oscillation is reduced, but eigenfrequency decreases and resonance frequency in driving mode is reduced
Solution Approach 1:
The patent carefully adjusts the geometric parameters to control the resonance frequency difference without significantly reducing the driving mode resonance frequency. By optimizing the mirror part and actuator dimensions, it achieves abnormal oscillation suppression while maintaining the resonance frequency in the driving mode above a certain threshold, thus preserving displacement angle performance.
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 configuration effectively suppresses abnormal oscillation, allowing for higher displacement angles and improved optical scanning resolution, thereby enhancing the performance of micromirror devices in applications like laser displays.
Implementation Method 1
a first actuator that has first piezoelectric elements disposed in an annular shape around the mirror part, the first actuator being connected to the mirror part and reciprocally rotating the mirror part about the first axis by periodically deforming the first piezoelectric elements
Implementation Method 2
a second actuator that has second piezoelectric elements, the second actuator reciprocally rotating the mirror part about the second axis intersecting with the first axis by periodically deforming the second piezoelectric elements
Implementation Method 3
a mirror part having a reflecting surface which reflects incident light and that changes two-dimensionally an orientation of the reflecting surface by reciprocally rotating the mirror part about two axes of a first axis and a second axis intersecting each other
Data Source
AI summary
The micromirror device includes a mirror part, a first actuator that reciprocally rotates the mirror part about the first axis, and a second actuator that reciprocally rotates the mirror part about the second axis. A resonance frequency Ain a lowest-order resonance mode as a resonance mode in which the mirror part and the first actuator are rotated about the first axis in opposite phases to each other, a resonance frequency B in a lowest-order resonance mode as a resonance mode in which the mirror part and the first actuator oscillate in opposite phases in a direction orthogonal to both of the first axis and the second axis, a frequency difference F=A−B, a resonance frequency C less than F and closest to the F, and a resonance frequency D greater than F and closest to F satisfy F−C≥20 Hz and F−D≤−150 Hz.