Patent ID: 6621550
Filing Date: 2003-09-16
Classification: G02F

Abstract:
A guest host liquid crystal display device, comprising:(a) first and second substrates positioned with a gap therebetween, the first and second substrates each having an interior surface facing the gap; (b) a guest host liquid crystal within the gap dispersed in a homeotropic geometry; (c) a reflecting layer within the gap and the first substrate; (d) a quarter wavelength plate layer within the gap; (e) first and second electrodes respectively provided on the inner surfaces of the first and second substrates so that a voltage can be applied to the guest host liquid crystal via the electrodes; (f) wherein the guest host liquid crystal mainly comprises a nematic liquid composition having a value of a negative dieletric anisotropy within a range of âˆ’2 to âˆ’10; a black dichroic dye dispersed in the liquid crystal that changes from an achromatic transmission state to an absorption state in response to the application of a voltage, the dye being 1-5% by weight of the liquid crystal; (g) the crystal composition is aligned to be perpendicular with respect to the surfaces of the upper and lower substrates when no voltage is applied across the electrodes.