Recently, a transparent display has got much attention as one of the next generation display devices. Especially, active studies on a transparent display using organic light-emitting diodes (OLEDs) are in progress. However, since it is not possible to obtain black color using a transparent OLED, it suffers from poor visibility. This inevitable problem can be solved by using a light shutter. Light shutter technology can be divided into two types; light absorption and scattering. However, a light shutter based on light absorption cannot block the background image perfectly and a light shutter based on light scattering cannot provide black color. In this work we demonstrate a light shutter using two liquid crystal (LC) layers, a light absorption layer and a light scattering layer. To realize a light absorption layer and a light scattering layer, we use the planar state of a dye-doped chiral nematic LC (CNLC) cell and the focal-conic state of a long-pitch CNLC cell, respectively. The proposed light shutter device can block the background image perfectly and show black color. We expect that the proposed light shutter can increase the visibility of a transparent display.

Date Published: 11 March 2015
PDF: 5 pages
Proc. SPIE 9384, Emerging Liquid Crystal Technologies X, 938417 (11 March 2015); doi: 10.1117/12.2077055

Published in SPIE Proceedings Vol. 9384:
Emerging Liquid Crystal Technologies X
Liang-Chy Chien; Harry J. Coles; Hirotsugu Kikuchi; Ivan I. Smalyukh, Editor(s)