USE OF A LIQUID CRYSTAL-BASED MATERIAL FOR THE PRODUCTION OF AN ELECTRO-OPTICAL BLOCKING DEVICE, AND DEVICE AND STROBOSCOPIC HELMET IN ACCORDANCE THEREWITH

摘要

The invention relates to the use of an electro-optical material which combines at least one chiral ferroelectric smectic liquid crystal and/or at least one antiferroelectric liquid crystal and a polymer, for the production of an electro-optical blocking device (11, 12) which can be switched, e.g. using a stroboscopic mode, between an on state (1112; 1211, 1212) and an off state (Sl = 1111; S2) and which is in the off state in a stable manner when no electric field is applied to the electro-optical material, said off state corresponding to a single stable state of the electro-optical material. The blocking device (11; 12) comprises a cell (111; 121) including two glass slides which are coated with a polarising film (112, 113; 122, 123) and said device can be used to produce arc welding helmets.