Color-selective circular polarizer and its use

Abstract

The circular polarizer comprises a liquid crystal cell, the liquid crystal layer (8) of which is present as a so-called "blue phase" and can be exposed to a variable electric field. The blue phase is an optically isotropic chiral phase which, like the cholesteric phase, reflects circularly polarized light within a narrow frequency band and accordingly, in this spectral region, transmits only light which is circularly polarized (in the opposite sense). Under the influence of the field, the reflection band changes its position and can be shifted almost continuously from blue to red by means of relatively small voltage changes. The circular polarizer can, by means of simple additional measures, for instance by including a color-neutral circular polarizer, be developed into a color modulator and, in particular, it also makes a multi-colored display of information possible.

Dependencies are inferred from the claim text.