Fremgangsmåde og apparatur til tilvejebringelse af en beskyttende belægning på en fotoledende overflade ved elektrofotografiske kopieringsmaskiner

1,272,815. Cleaning electrostatic surfaces. INTERNATIONAL BUSINESS MACHINES CORP. Sept. 5, 1969 [Sept. 26, 1968], No.43962/69. Heading G2H. Residual toner is removed from the photoconductive layer 25 of a xerographic drum by a rotatable brush 49 which deposits fluorinated hydrocarbon material which is stated to reduce the build-up of a toner film. The brush fibres may be of fluorocarbon resins e.g., polytetrafluoroethylene, polyvinylfluoride, polyvinylidenfluoride, polychlorotrifluoroethylene, copolymers of tetrafluoroethylene with tetrafluoropropylene. A fibrous web may be used in place of the brush. A rod 53 removes toner particles from the brush which are then drawn by vacuum means to a filter bag 52.