Characteristics of in-air thermoplastic recording.

Concepts and characteristics of in-air thermoplastic recording are reviewed. The in-air method of electrophotographic recording relies upon a gaseous discharge of air molecules to form a latent charge pattern in the likeness of the image. Modulation is achieved with a light sensitive photoreceptor, and images are stored as surface deformations on the thermoplastic film. Development is instantaneous with heat, projection by schlieren optics, and erasure by melting the thermoplastic. The technique has been applied to (1) document type recording, where the entire image appears simultaneously, and (2) the recording of charactron type CRT images, where the information appears as a rapid short-time sequence of high intensity alphanumeric symbols. Problem areas are studied with the aid of the equivalent circuit and its transient analysis. Resolution, reciprocity, photoconductor characteristics, reusability, image sampling, and the effects of humidity are discussed.