Heat transfer and optical density of prints obtained with electrothermal printheads

Abstract

A discussion is given of the optical properties utilized to form thermographic prints, the method of treating the mottled appearance of prints, the experimental means for determining the characteristic parameters entering into the theoretical formulation, and the experimental results concerning heat transfer and optical density of the thermal prints. The experimental results confirm that the theory developed here encompasses and describes correctly all significant practical cases. The theory fails only for very coarse prints, which, however, represent a case of little practical interest.