Electromechanical Actuator Coupling Reduction via Safe Positioning

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Solution Overview

Problem

Portable electronic devices with voice coil actuators face challenges in reducing mechanical coupling effects during shock and vibration, which can lead to rattling and wear of camera modules and other electromechanical components.

Innovation Solution

A controller system is integrated with a vibration motor and accelerometer to detect mechanical events and select actuator signals that position the lens carrier between safe focus positions, reducing mechanical coupling effects by moving the lens carrier to a safe intermediate position between infinity and macro focus positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a voice coil actuator is used to position the lens carrier for focusing, then image quality and focal range are improved, but mechanical coupling effects during vibration and shock increase causing rattling and wear

Engineering Contradiction:

Improvefocusing precisionVSAvoidmechanical coupling effects

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The controller proactively positions the lens carrier to a predetermined safe position (e.g., infinity focus) before the mechanical event occurs, based on detection from sensors such as accelerometers or gyroscopes. This preliminary positioning prevents the lens carrier from being subjected to harmful mechanical coupling effects during vibration or shock events.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control system acts as an intermediary between the sensor detection and the actuator response, coordinating the timing and magnitude of actuator signals to position the lens carrier safely. The controller processes sensor data and generates appropriate actuator commands to mitigate mechanical coupling effects while maintaining focusing functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the lens carrier is actively positioned during vibration, then image stability is improved, but the complexity of the control system increases

Engineering Contradiction:

Improveimage stabilityVSAvoidcontrol system complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The system changes the operational parameters of the voice coil actuator dynamically - switching between normal focusing operation and protective positioning mode based on detected vibration or shock conditions. The controller adjusts actuator current and lens carrier position parameters in response to sensor inputs, enabling adaptive control without requiring permanently complex hardware.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the lens carrier is positioned in a safe position during mechanical events, then durability is improved, but the ability to capture images during the event is reduced

Engineering Contradiction:

ImprovedurabilityVSAvoidimage capture capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The control system operates in periodic cycles, switching between normal operation mode and protective positioning mode based on alternating conditions of mechanical stability and disturbance. During stable periods, the lens carrier performs focusing and image capture; during disturbed periods, it transitions to safe positioning. This periodic alternation preserves durability while maintaining productivity during favorable conditions.

Inventive Principle:

Principle #19Periodic action

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 solution effectively reduces mechanical coupling effects during vibrations and shocks, minimizing rattling and wear of camera modules and other electromechanical components, ensuring improved durability and image quality in portable electronic devices.

Implementation Method 1

The controller may be configured to detect the mechanical event based on the acceleration being over a threshold determined by the mass of and biasing force on the mechanical element

Methodology Applied

Scientific EffectAcceleration detection: Accelerometer

Implementation Method 2

a camera having a voice coil actuator for positioning a lens carrier element between infinity and macro focus positions

Methodology Applied

Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 3

based on a spring bias force acting on the lens carrier

Methodology Applied

Scientific EffectSpring force: Spring

Data Source

PatentUS8862182B2Coupling reduction for electromechanical actuator

Publication Date: 2014.10.14 APPLE INC

AI summary

A portable electronic device comprises an electromechanical module having an actuator for positioning a mechanical element between first and second positions, and a controller coupled to the electromechanical module. The controller is configured to detect a mechanical event coupling to the electromechanical module, select an actuation signal to position the mechanical element in a safe position between the first and second positions, and transmit the selected signal, such that the mechanical element is positioned in the safe position during the event.