GB964882A - Improvements in or relating to electrostatic recording - Google Patents

Abstract

964,882. Photoconductive recording and playback. GEVAERT PHOTO-PRODUCTEN N.V. May 17, 1961 [May 17, 1960], No.23487/63. Divided out of 964, 880. Heading G5R. [Also in Division H1] An electro-optical process for recording and playback wherein optical information is stored on a photoconductive layer, such as described in J.S.M.P.T.E.69 Jan. 1960, pp. 32-35, but using a simpler photoconductive record medium readily erasible by exposure to light. Whereas, in the known record shown, a transparent base I, a transparent conductor II, a photoconductor III, typically of SbS 3 and a top, insulating layer of pure polystyrene IV and spacer/conductors V were required, the new record substitutes a single layer of photoconductive polymer for the layers III and IV, or alternatively, since this material can be made into a self-supporting tape, it may be used alone by drawing it over a conductive support. A preferred tape comprises a self-supporting layer of poly (N-vinylcarbazole) or its copolymers,prepared as in Specification 964, 875, methylene chloride and Janus green B,the layer having a conductive layer (cf. II) and conductive strips (cf. V) coated on to it. For playback, the stored charges are extracted as a signal. Divisional Specifications 964,880 and 964,883 are referred to,as are Specifications 856,770, 964,871, 964,877 and 964,879,referring to other suitable photoconductors.