Voice Coil Motor Rotor Posture for Autofocus and Handshake Compensation
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Solution Overview
Problem
Conventional camera modules lack an auto focus function that adjusts the gap between the lens and image sensor, leading to image quality degradation due to user-induced handshake.
Innovation Solution
A Voice Coil Motor (VCM) system that simultaneously performs focusing operations and handshake compensation by varying the rotor's posture in response to the lens posture, using a rotor with a driving unit, a stator with an electromagnetic interaction unit, and an elastic member to maintain optimal positioning and reduce current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the rotor is kept in contact with the base to maintain positioning, then positioning stability is improved, but current consumption increases due to continuous electromagnetic force application
Solution Approach 1:
The rotor is designed to dynamically change its position relative to the base, switching between contact state (for positioning stability) and separated state (for reducing current consumption). The driving unit controls the rotor to be separated from the base when positioning is not required, eliminating continuous electromagnetic force application and reducing energy consumption while maintaining stability when needed.
2Adaptability or versatility
If the elastic member is allowed to move freely to accommodate rotor movement, then movement flexibility is improved, but interference with the case or housing occurs during rotor ascent or descent
Solution Approach 1:
An interference prevention unit is introduced as an intermediary element between the elastic member and the case/housing. This unit selectively allows the elastic member to move freely during normal operation while preventing contact and interference with the case or housing during rotor ascent or descent, thus resolving the contradiction between movement flexibility and interference prevention.
3Adaptability or versatility
If the rotor is driven to both directions for focusing operation, then focusing versatility is improved, but driving faults occur when no driving signal is applied
Solution Approach 1:
The rotor is preliminarily positioned in a separated state from the base before driving signals are applied. This preliminary positioning prevents driving faults by ensuring the rotor is in a known, stable state before bidirectional focusing operations begin, thereby improving reliability while maintaining focusing versatility.
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 VCM system enhances image quality by reducing current consumption, eliminating mechanical offsets, and improving camera module design freedom, while preventing driving faults during focusing operations.
Implementation Method 1
a stator formed with a second driving unit driving the rotor in response to electromagnetic interaction with the first driving unit
Implementation Method 2
an elastic member coupled at one side to the rotor and coupled at the other side to the stator
Data Source
AI summary
An exemplary embodiment of the present invention a rotor including a lens and formed with a first driving unit, a stator formed with a second driving unit driving the rotor in response to electromagnetic interaction with the first driving unit, and a base on which the stator is fixed, wherein the rotor is brought into contact with the base, in a case the lens is in a UP posture, and the rotor is distanced from the base, in a case the lens is in a DOWN posture.