Fast Response Characteristics in Liquid Crystal Display in Operating Mode of the Nematic Liquid Crystal

• Published in: Molecular crystals and liquid crystals (Philadelphia, Pa. : 2003) Vol. 434; no. 1; pp. 123/[451] - 133/[461]
• Main Authors: Bae, Yu-Han, Hwang, Jeoung-Yeon, Kim, Kang-Woo, Seo, Dae-Shik
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.06.2005
• Subjects: polyimide (PI); response time; transmittance; twisted nematic (TN); Δnd
• ISSN: 1542-1406; 1563-5287
• DOI: 10.1080/15421400590955604

In this study, we investigated response characteristics of liquid crystal display (LCD) with different operating mode of nematic liquid crystals (NLCs) such as 45° twisted nematic (TN), 67.3° TN and electrical controlled birefringence (ECB) on the rubbed polyimide (PI) surface with side chains. The pretilt angles generated on polyimide surfaces of the three kinds of LCD operating modes were about 12° that was higher than those of conventional TN-LCDs. Also, the Electro-optical (EO) performance of these LCDs showed stable condition. Low transmittance of the 45° TN and 67.3° TN cell on the rubbed PI surface were measured by using low cell gap d. The fast response time in ECB cell among the three kinds of LCD operating modes was achieved. Also, the electro-optical characteristic of three kinds of TN-LCD on the rubbed PI surface was investigated. The threshold voltage and the response time of thermal stressed TN-LCDs showed the same performances on no thermal stressed TN-LCDs. There was little change of value in these TN cells. However, the transmittances of TN-LCDs on the rubbed PI surface decreased while increasing thermal stress time. Therefore, the thermal stability of TN-LCD was decreased by the high thermal stress for the long duration.