MEMS Optical Scanner with Rigidity Wire for Shock Resistance
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Solution Overview
Problem
Conventional MEMS optical scanners suffer from poor shock resistance and low efficiency in rotary driving along the V-axis, leading to instability and stray light issues during image display.
Innovation Solution
A MEMS optical scanner design incorporating a silicon substrate with a flexible printed circuit board and a rigidity-enhancing wire structure, where the wire is fixed to the substrate to increase its resonant frequency and torsional rigidity, allowing for efficient ramp wave driving while maintaining shock resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a silicon substrate is used for the mirror support structure, then manufacturing precision and integration are improved, but shock resistance deteriorates
Solution Approach 1:
The patent combines a silicon substrate (for manufacturing precision and integration) with a flexible printed circuit board (for shock resistance). The silicon substrate contains the mirror and driving portion, while the FPCB provides mechanical support and absorbs shocks, creating a composite structure that leverages the advantages of both materials.
2Reliability
If rotary driving centering on V-axis is performed in resonance mode with flexible printed circuit board, then shock resistance is improved, but driving efficiency deteriorates
Solution Approach 1:
The patent makes the support structure dynamically adjustable by introducing a rigidity giving portion that can change the resonant frequency of the FPCB. This allows the system to adapt its mechanical properties during operation, enabling efficient ramp wave driving while maintaining shock resistance through controlled dynamic behavior.
3Productivity
If the flexible printed circuit board is made more rigid to increase resonant frequency, then driving efficiency is improved, but shock resistance deteriorates
Solution Approach 1:
The patent segments the support structure into distinct functional portions: the FPCB base structure maintains flexibility for shock absorption, while a separate rigidity giving portion (wire or rod) provides localized stiffness enhancement. This segmentation allows independent optimization of shock resistance and driving efficiency.
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 design enables stable and efficient rotary movement of the mirror along both axial directions, enhancing shock resistance and preventing stray light, thereby achieving high-quality image display.
Implementation Method 1
the mirror is driven through the sub-arms and the main arms by expanding and contracting the piezoelectric film and by applying a drive signal to the piezoelectric film
Implementation Method 2
having a Young's modulus that increases rigidity and a resonant frequency of the second substrate, and the rigidity giving portion drives the support portion in the second axial direction
Data Source
AI summary
Provided is a MEMS optical scanner that stably performs a scan with light by rotary moving a mirror centering on a V-axis in coincidence with a resonant frequency that enables ramp wave driving while securing shock resistance. The MEMS optical scanner includes a first substrate, a driving portion that drives the mirror by a piezoelectric film in a first axial direction where the piezoelectric film is installed on the first substrate, a frame that supports a driving portion, a second substrate, a support portion that supports the first substrate, a frame portion spaced from and surrounding the support portion, and an axis portion that supports the support portion and the frame portion along a second axial direction. It also includes a rigidity giving portion fixed to the second substrate at both ends thereof along the second axial direction and that drives the support portion in the second axial direction.