Abstract:
Apparatus for reproducing, on an electrically insulating film, an electrostatic charge pattern in an intensified form comprises two cylinders, disposed parallel to each other, and apparatus to reciprocate them in opposite directions of rotation with respect to each other. The image- bearing surface is on one cylinder; and the film, on which the charge pattern is to be reproduced, has opposite ends secured to the two cylinders, respectively. Grounded wetted sponges are disposed adjacent opposite surfaces of the film so as to first induce a monopolar charge pattern on the film, during one direction of rotation of the cylinders, and then to induce a bipolar pattern on the film, during an opposite direction of rotation of the cylinders.
Abstract:
A corona generating device, adapted to operate in air, to apply an electrostatic charge to a surface, includes an elongated, knife-edged, corona-generating electrode enclosed within a housing. The housing includes a foraminous screen that has an optical transmission of less than 50 percent to prevent ultraviolet light produced by the corona from reaching the surface to be charged. The screen and the interior of the housing are formed, or coated, with a catalytic material, such as silver, to convert any ozone formed by the corona discharge, to oxygen, thereby preventing pollution of the air with toxic ozone.