Reflective bistable cholesteric/polymer dispersion display with a black polypyrrole electrode cast from the solution

A reflective mode bistable cholesteric/polymer dispersion(CPD) display is p roposed in which both the electrode and the light-absorbing layer of the co nventional display were substituted with a single polypyrrole(PPy) layer sp in-cast from the chloroform solution. Utilization of the black conductive P Py film coated on the inner surface of the rear glass plate not only provid ed a convenient and economic method of fabricating CPD displays but also im proved the contrast ratio by about 20%. By incorporating 20% of polymer int o the chiral nematic mixture, the bistability and the viewing angle of the display were remarkably enhanced while the reflectance decreased from 89 to 29%.