Scavenging apparatus

Claim 1

In an electrostatographic copier or printer in which desired latent images, formed on the imaging surface of an imaging member, are made visible with charged, loose particles of toner that are electrostatically attracted and held to the latent image at a development station, and in which the desired loose toner image, so developed, is thereafter transferred at a transfer station to a suitable receiver for fusing thereto, a scavenging apparatus for removing, prior to such desired image transfer, unwanted particles from the image and non-image areas of the imaging surface of such imaging member, without adversely affecting the wanted toner particles forming the desired image remaining thereon, the scavenging apparatus including: (a) a conductive shell spaced from the imaging surface of the imaging member, said shell having an electrical potential source connected thereto creating an electrostatic field for electrostatically loosening such unwanted particles on the imaging surface without adversely affecting the wanted loose toner particles forming the desired image remaining thereon; (b) a rotatable magnetic roller disposed inside said stationary shell, said magnetic roller creating a magnetic field about said shell for attracting and removing from the imaging surface, any loosened particles that are magnetizable; and (c) a vacuum system having a pickup nozzle, said pickup nozzle being adjacent said shell spaced from the imaging surface of the imaging member and said vacuum system being useful for pneumatically augmenting the removal of unwanted particles otherwise (i) magnetically being removed by said magnetic roller, and/or (ii) electrostatically under a removal tendency from said shell, as well as, being useful for pneumatically and directly removing non-magnetic unwanted particles from the imaging surface.