GB1105787A - Improvements in "recording medium" - Google Patents

Abstract

1,105,787. Electro-photographic images. GENERAL ELECTRIC CO. Jan. 24, 1966 [Jan. 25, 1965], No.3092/66. Heading G2H. Erasable images are formed by applying an electrical pattern (e. g. from electrodes or an electron beam) on the surface of layer 3 of an imaging member comprising, in order, a conductive layer (1), a layer (2) containing reactive material (e. g. ions or colloids) which migrate in response to an applied electrical field, and a layer (3) which is capable of changing at least one physically distinguishable characteristic in response to the presence of said reactive material. In embodiments, layers 1 and 2 may be in the form of a roller or layer 3 may be overcoated with a layer of resin (e. g. polystyrene) and the electrical pattern applied to the surface of this layer induces a corresponding pattern of the surface of layer (3). Layer (2) comprises an ion exchanger, quinone/hydroquinone, an oxidation/ reduction polymer, an aminoacid, a colloid, or a solutions of ions gelled by, for example, agar, gelatine, starch, or polyvinyl alcohol or acetate. The image may be produced on layer (3) by volume changes in a polymeric electrolyte, formation of vat dyes from leuco bases and vice versa, formation of coloured salts (e. g. PbS, Cus, FeS) and vice versa, polymerization and cross-linking, formation or decomposition of organometalliccompounds, precipitation or dissolution of compounds and elements, ester formation, hydrolysis, staining of amino acids, and change in pH resulting in change in pH indicator. The image may be erased by applying a reverse potential or current uniformly across the plate.