音圈馬達之磁路創意設計與分析

Abstract

音圈馬達是相機鏡頭模組裡的重要元件，擔任致動器的角色。隨著自動對焦、高倍數變焦、以及攝影技術的進展，對於精準、快速的音圈致動器的需求也越來越高。音圈致動器的主要結構是由永久磁鐵、導磁軛鐵和致動區域的空氣間隙所組成之磁路，因此為了得到高效能的音圈致動器，選擇最佳的磁路設計尤為重要。於是，我們利用列舉演算法，基於音圈馬達的特性，以圖論的方式定義，而列出所有的磁路設計，並且利用流值方法、基因演算法以及有限元素法，進行比較。在選定好設計之後，為了使磁路在現有的限制條件底下，達到最佳的致動能力，於是我們利用基因演算法來進行最佳化的程序。最後，再對磁路中的各個元件，考慮其不同形狀所造成的差異，從中選擇最好的磁路設計。在本研究當中，以各種方法建立了一個完整的磁路設計程序，並且適用於各種應用之音圈馬達，更利用此設計方法，設計並製作出新磁路結構之音圈馬達。

The voice coil motor is the important part of lens modules in cameras. It plays the role of the actuator. Due to the development of the auto-focus system, high-multiple zooming system, and the photograph technology, the demand of precise and fast voice coil actuators is increasing. Voice coil actuators consist of permanent magnets, yokes, and gaps. For high efficiency, optimal magnetic design is very important. Hence, this study characterizes voice coil motors using the graph theory to enumerate all designs of the magnetic circuit. In addition, the flow value method, the genetic algorithm, and the finite element analysis are used to compare performance among enumerated designs. After choosing a design based on flow values where smaller ones represent less energy loss, for optimal actuator force under constraints, we use the genetic algorithm to carry out optimization. Finally, we also consider the effect of different shapes for magnetic components and choose the best design. This study presents a complete design process for any application of voice coil motor.