title: Dual-mode operation of a twisted nematic liquid crystal cell by switching between dynamic and memory modes.
abstract: We propose a twisted nematic liquid crystal device that can be operated in dynamic or memory mode, based on the information content to be displayed at that time. +90°-twisted and -90°-twisted states are used as two stable states for operation in the memory mode. A vertical electric field is applied to realize gray levels for operation in the dynamic mode. The proposed device has a memory retention time of over a month for the memory mode and a response time of 12 ms for the dynamic mode. Contrast ratios of over 500∶1 can be obtained in both the dynamic and memory modes.
authors.affiliation: School of Electrical Engineering, Pusan National University, Busan 609-735, South Korea.
authors.forename: Dong Han
authors.initials: DH
authors.lastname: Song
authors.forename: Ki-Han
authors.initials: KH
authors.lastname: Kim
authors.forename: Jung-Wook
authors.initials: JW
authors.lastname: Kim
authors.forename: Jae Chang
authors.initials: JC
authors.lastname: Kim
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Yoon