Yeon Jeongho, Koh Tae-Wook, Cho Hyunsu, Chung Jin, Yoo Seunghyup, Yoon Jun-Bo
Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, South Korea.
Opt Express. 2013 Apr 22;21(8):10358-66. doi: 10.1364/OE.21.010358.
Transparent display is one of the most promising concepts among the next generation information display devices. Nevertheless, conventional transparent displays have two inherent problems: low forward light efficiency due to the light being emitted also in a backward direction; and low legibility due to the visual interruption caused by the light coming from the background. In this work, a cholesteric liquid crystal (Ch-LC) based, actively operational blind panel is combined with transparent organic light-emitting diodes (TR-OLEDs) to recycle the light wasted by backward propagation in transparent displays while blocking the light from behind the display, pursuing both improved forward light efficiency and enhanced image legibility. By tuning the reflectance spectrum of the Ch-LC panel to match the emission spectrum of TR-OLEDs, we achieved luminous efficiency increase by as large as 21% (85%) when the top metal cathode side (the bottom ITO side) of the OLEDs fa'transparent OLED' ces the blind panel. Maximum transmittance of the proposed device reached a high value of 60%, successfully demonstrating a new window-like transparent display concept.
透明显示器是下一代信息显示设备中最具前景的概念之一。然而，传统透明显示器存在两个固有问题：由于光也会向后发射，导致前向光效率较低；以及由于来自背景的光造成视觉干扰，导致可读性较低。在这项工作中，一种基于胆甾相液晶（Ch-LC）的有源操作盲面板与透明有机发光二极管（TR-OLED）相结合，以回收透明显示器中向后传播而浪费的光，同时阻挡来自显示器后方的光，从而提高前向光效率并增强图像可读性。通过调整Ch-LC面板的反射光谱以匹配TR-OLED的发射光谱，当OLED的顶部金属阴极侧（底部ITO侧）面对盲面板时，我们实现了高达21%（85%）的发光效率提升。所提出设备的最大透过率达到了60%的高值，成功展示了一种新的类似窗口的透明显示概念。
