GB1016836A - Electrophotographic copying apparatus - Google Patents

Abstract

1,016,836. Electro-photographic processes. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 29, 1964 [June 28, 1963], No. 22278/64. Heading G2H. An electro-static latent image is developed by tones material carried by a web 27 of backing material, e.g. insulating paper or polyester film with minute parallel conductive paths. The image is formed on a drum 11 having a photo-conductive coating 12 such as selenium by first charging at station 17 and then exposing the surface 12 image wise at station 22. The web 27 unwound from a braked supply roll 28 and electrostatically charged before passing through trough 35 containing toner 36, such that toner is held on the web by electrostatic force. Web 27 passes around roller 31 adjustably mounted with respect to drum 11, such that an air gap 42 is maintained between toner layer and coating 12. A charge of polarity opposite to that on the web 27 is deposited on roller 31 to decrease the attractive force between the toner and web 27 and to allow toner particles to be attracted only to areas of coating 12, where high potential exists. The developed image is transferred at station 51 to a web 52 and is fused by an infra red lamp 57. In another embodiment toner backing material 71 Fig. 3 (not shown) is adhesively coated and a thin layer of toner applied thereto before insertion in the apparatus. Toner supply is renewed by replacing a used toner backing roll by a replacement roll.