The basic spectral properties and the orientation of some dichroic flu
orescent dyes (derivatives of 4-amino-(N-ethylnaphthalimide)) in sever
al nematic liquid crystal matrices have been studied. Moreover, the te
mperature of the nematic-isotropic phase transition for the dye-liquid
crystal mixtures has been determined. It has been found that the dyes
investigated are characterized by parameters which make them applicab
le to both passive and active ''guest-host'' liquid crystal display de
vices.