Pyroelectric copying process

Abstract

An electrostatic copying process based on the pyroelectric effect is described. The effect is demonstrated with single crystals of LiTaO₃, ceramic plates of lanthanum‐modified lead zirconate‐titanate (PLZT), and polymer films of polyvinylidene fluoride (PVF₂). By employing thin films (0.8 mil) of PVF₂ to minimize thermal diffusion, we have obtained sufficient resolution to allow charge distributions (images) to be visually observed by dusting the films with conventional electrostatically charged inks. Since the pyroelectric effect is not wavelength dependent, certain advantages over photoconductive techniques, with their inherent wavelength dependence, are possible.