Liquid crystal alignment layers

Method of manufacturing an electro-optic passive display cell having a helical nematic liquid crystal comprising two plates between which is disposed the said crystal, according to which one deposits on the inner face of each of the said plates an alignment film by evaporation under vacuum under an incidence ensuring an alignment of the molecules of the liquid crystal which thus orientate themselves along a direction determined by the process of evaporation, characterized by the fact that one realizes the said film by applying, on at least one of the said plates, two layers of an alignment material under an incidence of about 5.degree., the projection, on the plate, of the vector of application of one of the said layers forming an angle of 180.degree. with the projection, on the plate, of the vector of application of the other layer, the whole in such a way that the molecules of the liquid crystal are then anchored on the said plate under an angle, smaller than 10.degree., such that the average anchoring angle on the two plates be smaller than 5.degree..