本文致力於設計出以線型態形狀記憶合金(SMA)為作動基礎之微型化鏡頭對焦致動器，研究係利用單向鎳鈦(NiTi)形狀記憶合金熱收縮應變的產品特性，設計異於目前小型鏡頭的對焦致動器所常用的音圈馬達（VCM）結構；文中之新型態致動器所使用之線型態形狀記憶合金當被加熱達到合金的沃斯田(Austenite)相變溫度後，合金線的長度會產生固定比率的應變收縮，當合金線的長度因為升溫產生應變收縮時，會推擠致動器內部的楔形塊傳動結構，透過形狀記憶合金線在高、低溫的相變過程中所產生的合金收縮與放鬆達成致動器系統的往復直線運動。 研究過程首先以實驗方式找出ψ0.1mm之NiTi形狀記憶合金線的收縮應變與荷重負載及驅動電流(溫度)之間的關聯，輔以搭配尺寸為34.0mm×34.0mm×10.8mm的楔形塊致動器模型，在經由量測得知致動器的作動反應速度後修正理論計算值；最終使用修正後的形狀記憶合金熱傳遞係數代入目標尺寸為8.5mm×8.5mm×2.7mm的微型致動器，即可預先估算微型化後的形狀記憶合金致動器的作動性能。 在鏡頭對焦致動器的控制器方面，是以IC555電路模擬PWM訊號用以控制形狀記憶合金的升溫的情況，其目的在使形狀記憶合金線在升溫的過程中能均勻升溫，促使對焦致動器所產生的往復運動能夠平順流暢。 The thesis discusses and evaluates a model of miniature lens actuating system that incorporates wire-type shape memory alloy (SMA) as actuator. Nickel-titanium (NiTi) SMA "remembers" and returns its original shapes after deformed by applying heat to the alloy. The one-way memory effect of NiTi SMA wire is utilized to study the feasibility of replacing conventional actuators like voice coil motor, stepping motor, and Piezoelectric motor. The thesis starts from offline NiTi SMA wire (0.1mm) characteristics study. This SMA wire deforms and changes its length during temperature/stress change. This is known to transition from the martensite phase to the austenite phase, or the reverse. Thereafter same SMA wire is incorporated into a 34.0mm×34.0mm×10.8mm real wedge actuating system to discuss additional factors in designing real word system. This system utilizes length change of SMA wire to actuate wedge mechanism for lens movement. Also an IC555 controller is used to output pulse-width modulation (PWM) signal for smooth current control. Finally a miniature 8.5mmx8.5mmx2.7mm system is characterized utilized observation obtained.
