Electrophotography by Persistent Polarization due to Inverse Field.
A new method of electrophotography has been developed utilizing: (1) dark polarization of photo-conductive material released and rebuilt in the reverse direction in a very short time by applying light image and reverse field simultaneously; (2) the idea of capacitance image. CdS or SeTe was used as semiconducting material for the photoreceptor, which consists of four layers: the top layer is an insulating sheet about 9 micro thick, the second a photosensitive layer 75 micro thick, the third is an insulating blocking layer about 6 micro thick, and the fourth a carbon base electrode. This method has two steps of charging as its features: (1) the top insulating layer is charged by means of corona discharge; (2) light image and reverse field are given simultaneously, and then the electrostatic latent image is formed. Finally, over-all illumination is given, forming the capacitance image which is to be developed by the brush method. This new method uses materials of very low dark resistance which have never been used before. A clear image has been made on a CdS plate by 2-3 lx sec exposure, or on a SeTe plate by 0.05-0.1 lx sec.
Yoshida
K
K
Kinoshita
K
K
Kawamura
T
T