GB1284915A - Apparatus for developing electrostatic images - Google Patents

Abstract

1284915 Developing electrostatic images R C A CORPORATION 12 Dec 1969 [19 Dec 1968] 60681/69 Heading G2H In an electrostatic printing machine in which electrostatic image areas occupy only a small part of a sheet, a developing apparatus transports toner to regions adjacent the image areas only, from where toner can be attracted imagewise to the sheet, by means of a plurality of similar conveyor means one or more of which is selectively actuable manually or automatically. In one embodiment the conveyor means comprise a number of wheels 70 disposed side by side and frictionally driven by rectangular shaft 26 through resilient splines 84 Fig. 4 (not shown) and arranged below toner container 60 to receive toner in recesses 98 and deliver it to transfer roller 36 which is contacted by magnetic roller 46 contacted by sheet 14. The electrostatic images are produced by character electrodes 120 on receipt of a pulse from a computer which pulse also actuates one or more of a series of arresting pins 108, one for each wheel 70, to project into a recess 98 of a wheel 70 thus locking it and preventing toner from being applied to the corresponding area of sheet 14. In a second embodiment, the conveyor means comprise a plurality of outlets for toner container 10a Fig. 7 (not shown) which are opened or closed by plungers (140) selectively movable by solenoid means (110) to allow toner to fall by gravity onto transfer roller 36.