MEMS Mirror Support Structure for Large Scan Angle Stability
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Solution Overview
Problem
Increasing the length of beam units in MEMS devices to achieve a large scan angle results in a decrease in natural resonance frequency and mechanical strength, leading to shaking and instability.
Innovation Solution
The introduction of a movable apparatus with a meandering structure and piezoelectric driving units to support and drive the reflection surface, enhancing mechanical sensitivity and maintaining resonance frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the length of beam units is increased to achieve a large scan angle, then the mechanical driving sensitivity is improved, but the natural resonance frequency decreases and mechanical strength decreases
Solution Approach 1:
The actuator is divided into multiple beam units (first beam unit, second beam unit, third beam unit, fourth beam unit) arranged in a meandering pattern. This segmentation allows the total actuator length to be extended for large scan angle while keeping individual beam unit lengths shorter to maintain natural resonance frequency and mechanical strength.
Solution Approach 2:
The beam units are arranged in a meandering (two-dimensional) pattern rather than a simple linear extension. This dimensional change allows the actuator to achieve extended effective length for large scan angle while maintaining compact individual beam segments that preserve mechanical strength and resonance characteristics.
2Ease of operation
If the length of beam units is increased to achieve a large scan angle, then the mechanical driving sensitivity is improved, but the mechanical strength decreases
Solution Approach 1:
The actuator is divided into multiple beam units (first beam unit, second beam unit, third beam unit, fourth beam unit) arranged in a meandering pattern. This segmentation allows the total actuator length to be extended for large scan angle while keeping individual beam unit lengths shorter to maintain natural resonance frequency and mechanical strength.
Solution Approach 2:
The beam units are arranged in a meandering (two-dimensional) pattern rather than a simple linear extension. This dimensional change allows the actuator to achieve extended effective length for large scan angle while maintaining compact individual beam segments that preserve mechanical strength and resonance characteristics.
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 solution maintains natural resonance frequency while achieving a large scan angle, reducing shaking and improving mechanical strength.
Implementation Method 1
a driving beam constructed by stacking a thin piezoelectric material on the elastic beam is configured to drive (rotate) the movable unit
Data Source
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AI summary
A movable apparatus (13) includes a movable unit (103) including a mirror (102) configured to reflect light, a support portion (104a, 104b) including a first end and a second end, the first end being connected to the movable unit, the support portion configured to swingably support the movable unit, and a fixed unit (108) connected to the second end of the support portion, wherein the support portion includes a plurality of beam units (115) and a connection unit (116) connecting adjacent beam units of the plurality of beam units, wherein where the support portion is divided into two parts at a predetermined or given position, the two parts including a first part closer to the fixed unit and a second part closer to the movable unit, a beam unit of the plurality of beam units in the first part has a higher rigidity than a beam unit of the plurality of beam units in the second part, and the beam unit of the plurality of beam units in the second part is longer than the beam unit of the plurality of beam units in the first part.