MEMS Actuator Foreign Substance Removal via Reiterated Vibration
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Solution Overview
Problem
Camera modules with MEMS actuators face challenges in maintaining focus adjustment due to foreign substances that interfere with electrostatic forces, leading to errors in focus adjustment and reduced camera performance.
Innovation Solution
A camera module with a MEMS actuator that uses electrostatic force to move lenses, incorporates an electrostatic capacity measurement unit to detect foreign substances, and drives the actuator to reiterated vibrations to remove these substances, utilizing adhesives to capture and remove foreign substances from the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a MEMS actuator uses electrostatic force to move the lens for focus adjustment, then the focus adjustment function is achieved, but foreign substances inside the actuator interfere with the electrostatic force and cause errors in focus adjustment
Solution Approach 1:
The patent applies mechanical vibration by driving the MEMS actuator to vibrate repeatedly at a specific frequency. This vibration causes foreign substances inside the actuator to move and collide with the housing, eventually making them adhere to the housing and be removed from the electrostatic field region, thereby eliminating their interference with the electrostatic force and improving focus adjustment reliability
Solution Approach 2:
The patent implements periodic action by applying voltage to drive the MEMS actuator in repeated vibration cycles. The periodic voltage application creates continuous vibrational motion that systematically removes foreign substances over time, transforming the static problem of foreign substance interference into a dynamic removal process that restores and maintains reliable focus adjustment
2Reliability
If the MEMS actuator is driven to reiterated vibration to remove foreign substances, then foreign substances are removed from the actuator, but energy is consumed for vibration
Solution Approach 1:
The patent uses periodic action by applying voltage intermittently to drive the MEMS actuator in repeated vibration cycles rather than continuous operation. This periodic voltage application creates vibration only when needed for foreign substance removal, reducing overall energy consumption compared to continuous operation while still achieving reliable foreign substance elimination and maintaining focus adjustment reliability
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
Effectively senses and removes foreign substances within the MEMS actuator, ensuring reliable focus adjustment and improved camera module performance by preventing foreign substance interference.
Implementation Method 1
a MEMS actuator moving a lens with electrostatic force
Implementation Method 2
an electrostatic capacity measurement unit measuring electrostatic capacity produced in the MEMS actuator
Implementation Method 3
An inner housing bottom surface, an upper surface and one of the both parts may be formed with an adhesive capable of sticking the foreign substance
Data Source
AI summary
Disclosed herein is a camera module having a MEMS actuator and a driving method thereof, the camera module with a MEMS actuator, including, a MEMS actuator moving a lens with electrostatic force, for focus adjustment, an electrostatic capacity measurement unit measuring electrostatic capacity produced in the MEMS actuator, a foreign substance determination unit determining if foreign substances exist in the MEMS actuator, and outputting a trigger signal when a foreign substance exists, and a MEMS actuator drive unit driving the MEMS actuator to a reiterated vibration using the trigger signal outputted from the foreign substance determination unit.