ENHANCED SCATTERING IN VOLTAGE SENSITIVE ENCAPSULATED LIQUID CRYSTAL

摘要

Encapsulated liquid crystal material in a support medium illuminated from the viewing side or direction or though a louvred light guide from the back side will appear bright or white relative to background when in distorted alignment, e.g. in the absence of an electric field. Incident light impinging on the liquid crystal material is isotropically scattered into the support medium, and using the principle of total internal reflection and possibly also optical interference a relatively large part of the isotropically scattered light is directed back to illuminate the distorted liquid crystal material tending to brighten the same so that light it scatters back to the viewing direction out of the support medium causes the liquid crystal material to appear relatively light or bright as compared to the background where there is no liquid crystal material or where the liquid crystal material is in parallel alignment in field-on condition, i.e aligned with respect to an electric field, and, thus, substantially transmissive. Original incident light where there is no liquid crystal material, that light which is isotropically scattered toward the back or non-viewing side of the display and within a certain cone or solid angle, and that light passing through aligned (field-on) liquid crystal material will tend not to be totally internally reflected; such light will pass through the support medium and may be absorbed by a remote black or colored material.