MEMS Actuator Radial Stator Design for Compact Scanning
Solution Overview
Problem
Conventional MEMS devices with tilting capabilities face challenges in reducing size due to intersecting cores and coils arranged along the rotation axis, leading to decreased space factor and increased complexity, making it difficult to miniaturize while maintaining effective operation.
Innovation Solution
The design incorporates a swing portion and frame structure that allows for orthogonal axis movement, featuring stator cores with tooth portions and extending portions arranged alternately, enabling efficient magnetic field utilization and reduced coil space requirements, thereby enhancing the optical scanning device's compactness and swing torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If cores and coils are arranged along the rotation axis in conventional MEMS devices, then the device can achieve tilting capability, but the device size increases and space factor decreases
Solution Approach 1:
The patent transitions from a conventional arrangement where cores and coils are positioned along the rotation axis to a configuration where stator cores are arranged radially around the central axis. This dimensional reorganization allows the optical element to achieve tilting capability while reducing the axial length and overall device volume, effectively solving the space constraint problem.
Solution Approach 2:
The patent divides the stator into multiple discrete stator cores arranged radially around the central axis, with each stator core having tooth portions that interact with the magnet. This segmentation allows for more efficient space utilization and enables the optical element to tilt without requiring large axial dimensions, thereby reducing device size while maintaining functionality.
2Device complexity
If cores and coils are arranged on the extension line of the rotation axis, then the structure is simplified, but gaps form between adjacent coils and space factor decreases
Solution Approach 1:
The patent repositions the stator cores from an axial arrangement to a radial arrangement around the central axis. This dimensional change eliminates gaps between adjacent coils that would form in a linear arrangement, maximizing the space factor while maintaining structural simplicity through the symmetric radial configuration.
3Adaptability or versatility
If the optical element needs to swing about orthogonal axes, then scanning capability is improved, but the device becomes more complex and harder to miniaturize
Solution Approach 1:
The patent segments the stator into multiple stator cores arranged radially, with each core having tooth portions oriented to produce magnetic fields in specific directions. By controlling currents in different stator cores, the optical element can swing about orthogonal axes independently, achieving versatile scanning capability while maintaining a compact and relatively simple device structure.
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 allows for a downsized optical scanning device with increased swing torque and reduced power consumption, while maintaining stable and efficient operation by optimizing the arrangement of stator cores and coils to enhance magnetic flux usage.
Implementation Method 1
when a current flows through each of coils arranged in each core, a magnetic field is applied to the permanent magnet by the opposing magnetic poles to tilt a support frame and a mirror structure
Implementation Method 2
a magnetic field is applied to the permanent magnet by the opposing magnetic poles to tilt a support frame and a mirror structure
Data Source
AI summary
An actuator that swings a swing portion about a first axis and a second axis perpendicular or substantially perpendicular to each other, includes a fixed portion, two first stator cores, two second stator cores, two first coils, and two second coils. The first coil is in the same region as a tooth portion of the first stator core, and the second coil is in the same region as a tooth portion of the second stator core. As viewed in a central axis direction, each extending portion of each of the first stator cores includes end surfaces that face a magnet and oppose each other with the magnet interposed therebetween along the first axis, and each extending portion of each of the second stator cores includes end surfaces that face the magnet and oppose each other with the magnet interposed therebetween along the second axis.