Reflectivity Improvement in Holographic Polymer Dispersed Liquid Crystal (HPDLC) Reflective Display Devices by Controlling Alignment

Munekazu DATE  Yoshie TAKEUCHI  Keiji TANAKA  Kinya KATO  

IEICE TRANSACTIONS on Electronics   Vol.E81-C   No.11   pp.1685-1690
Publication Date: 1998/11/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Electronic Displays)
reflective display,  polymer dispersed liquid crystal,  hologram,  alignment control,  shear force,  

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A method to improve the reflection efficiency of holographic polymer dispersed liquid crystal (HPDLC) is proposed and its effectiveness is confirmed. Controlling the alignment of liquid crystal (LC) in tiny droplets of HPDLC can increase the refractive-index difference between the LC droplet layer and the polymer layer, causing the peak reflectance and reflective spectral width to expand. We observed experimentally that 96% of the light components excluding the scattering loss can be diffracted in a transmission HPDLC device by ordering the LC. In a reflection HPDLC, we found that reflection could be improved by ordering through an applied shear force. Our findings should lead to an improvement in the quality of reflective display devices.