多環電極液晶透鏡之新製程

Abstract

在科技發達的今日，行動裝置具有高畫質的拍照功能已成基本配備，所以在相機鏡頭這一塊就顯得相當重要。一般手機大多追求輕薄等特點，沒有空間可以讓鏡片與感測器作相對位置的移動來達到光學變焦，故絕大部分的相機皆採用數位變焦，而數位變焦只是透過手機裡的處理器把影像每個畫素面積增大來達到放大的效果，對於解析度並無實質上的幫助，要提升解析度則必須利用光學變焦來取代數位變焦。 本實驗提出一個簡單的方法來製作具有多環電極之液晶透鏡，其最主要技術重點為利用氣溶膠噴墨系統在環狀ITO電極上噴塗一條PEDOT:PSS細導線，當電壓驅動時，電位在PEDOT:PSS導線上連續衰減，由於PEDOT:PSS的電阻率比ITO電極約大三個級距，故PEDOT:PSS與ITO電極的接觸點可視為節點，這表示環電極會與該接觸點電位相等，綜觀來看，便形成一個圓對稱且平滑的梯度電場，當注入液晶時便形成梯度折射率分布，可藉由電壓來調變折射率分布的梯度斜率，進而改變焦距。根據實驗結果，本實驗室所提出的方法只需要大約5 V即可使液晶透鏡有21 cm的焦距，此時聚焦時間約為1.2秒。

The high-quality camera has become the must-have equipment in mobile device. The current trend for mobile device is thin and weightless. There is no room to put the lens and sensor to achieve the Optical Zoom. Most cameras in mobile phones adopt Digital Zoom. The amplification effect is achieved by software process increasing the image pixels without enhancing the resolution. The Digital Zoom must be replaced by Optical Zoom to enhance the picture resolution.

This thesis presented a fabrication process to achieve multi-ring electrodes liquid crystal lens. The main focus of this method is to print a thin PEDOT:PSS line as voltage control line on the concentric ITO electrodes by aerosol jet printing system. The voltage will continuously decay via PEDOT:PSS line when applied voltage. The connecting point between PEDOT:PSS line and ITO electrode is a node, which the potential on ITO electrode ring is as same as the contact point. The symmetrical and smooth gradient electric field is formed. As a result, the LC lens has 21 cm focal length when applied 5 volts. The focusing time is less than two seconds.