![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
The rapid progress of the young liquid crystal display (LCD) technology is due to the synergisms resulting from combining research on electro-optical effects, liquid crystal materials and display technology. The design and production of liquid crystal molecules with specific physical properties and their application in displays based on the twisted nematic effect has led within only seventeen years from simple digital watch displays to high information content LCDs capable of reproducing color television pictures or graphics information on flat computer terminals. After reviewing those liquid crystal material parameters which strongly affect the display performance, the operating principle of the twisted nematic effect and its dependence on liquid crystal material properties is described.
The elastic, dielectric viscous, optical and mesomorphic properties of liquid crystals depend on specific molecular structural elements, such as on different hydrocarbon side chains, rigid cores and polar end groups. By specifically designing the molecules, synergetic effects are shown to result allowing to optimize the display performance and opening up new LCD applications.
The strong demand for large area, direct view and projection LCDs capable of reproducing high information contents not only requires new liquid crystals and actively addressed display substrates but often also new electro-optical effects with steep transmission-voltage characteristics such as those resulting from supertwisted nematic configurations. The black-white optical mode interference effect is shown to be one possibility to achieve—in combination with appropriate LC-materials—the required steep characteristics of highly multiplexed future LCDs.