創新異質整合智慧型手機相機模組之研究---子計畫四：創新液晶變焦透鏡應用於手機相機模組化鏡頭之實現(I)

Abstract

本計畫為開發一新型可調變焦距透鏡模組，利用液晶材料之雙折射率特性及液晶分子隨電場方向排列的特性，等效為漸變折射率(GRIN)之特殊光學透鏡，再加以調變不同驅動電壓大小，近而改變液晶透鏡之等效折射率。此折射率可產生焦距隨著電壓大小不同而有所變化，達到變焦之效果，得以取代傳統之玻璃或塑膠鏡片。計畫第一年，首先架構出變焦液晶透鏡之基本理論推導模型，並分析驗證液晶透鏡之光學性質與電場之關係，並運用模擬軟體對電場及光學性質加以佐證，設計出特殊驅動方法之液晶透鏡，並且製作液晶透鏡實體，搭配鏡頭模組驗證理論分析。另外建立標準之光學檢測系統，觀察液晶透鏡之干涉條紋推導出透鏡之光學成像性質，並建構一套焦距量測系統，以配合完成自動變焦液晶透鏡模組之前置作業。第二年開始以第一年所製作液晶透鏡為基礎，並整合整合子計畫五、子計畫六研發材料之新型液晶透鏡，配合第一年所建構之光學檢測系統加以分析實驗，並於第二年後期結合子計畫三之驅動晶片使智慧型照相模組前端部件更趨於完善。第三年將液晶透鏡與驅動晶片封裝與模組化，並加入子計畫一之防手振系統並利用子計畫三之數位影像修正系統補償提升影像品質，後期與CMOS影像感測器結合，最後完成自動對焦/變焦之液晶透鏡與光學防手振之智慧型像機系統整合。

This proposal is to design a novel tunable lens module using the birefringence property of liquid crystals (LC). The tunability of the designed LC lens in the foucs length is made possible by adjusting applied filed to turn the LCs inside the len to desired postures, acting as an gradient index lens (GRIN). This LC lens is best suitable for replacing moving objective lens in the compact cameras modeule (CCM) for mobile phones to implement the functions of auto-focusing and zooming. It is advantageous to replace conventional lens with lightweight and compact in some applications, include micro-lens module, cell phone component, fixed focal length web camera, blu-ray disk, three-dimension (3D) display, and optical tweezer. One can design positive and negative LC lenses to be combined with CCDs with conventional lens components for the LC lens module in order to performiong auto-focusing and zooming. In recent years, the on-line tunability in the focal length of a common variable focus lens is achieved by the mechanical motion of the individual lenses in CCM. The control mechanism for lens motion is generally complicated, and the movements of the lenses usually need a large space. To remedy the problem, the LC tunable lens is rpoposed and used in the CCM herein to save space in mobile phones. In the first year ofproject execution, it is planned to establish the optical model of the LCs and predictthe resulted index change distribution and the focus length. The theoretical predictions are also validated by commercial software. With the LC lens well designed, the lC lenses are optimized to lead to best focusing capability with a measure defined. Finally, in this year, an inspection machine for measuring the capability of the designed LC lens. In the second year, based on the experience gained in the first year, new LC materials leading to low voltage drives and fast reposnse offered by sub-projects 5 and 6 are adopted for a better tunable LC lens. Also conducted in this year are combining the developed LC lens with the color compensation chip developed by sub-project 3 to achieve high color gamma. Int eh last year, the maturally-developed LC CMM is integrated with the image stabilizer developed by sub-project 1 to form the novel CCM for camera phones, as proposed by the net-proposal.