A Study on Speed and Gradation in Simple Photosensitive Layers

Abstract

Exposure characteristics of photochemical and photoconductive-memory based photographic systems were analysed, on an assumption of the first or pseudo-first order kinetics. The concept of “reduced characteristic curve” was introduced, which was defined with dimensionless parameters to describe the general behavior of the image or latent image formation. Calculated curves for the diazo-film, the electrolytic electrophotography and the RS film well fitted to experimental observations.
The recording speed and the gradation were discussed on the basis of the above treatment. It was concluded that in ZnO-resin layers, the electron density in the latent image decays bimolecularly in the course of the development, and this contributes to improve the gradation.
A definition of the effective recording speed was proposed, which makes it possible to compare the speed with the ASA scale of silver halide processes.