Patents Assigned to Elfotec A.G.
  • Process for improving the photoelectric properties of a laminated charge image carrier
    Patent number: 4386148
    Abstract: A process for improving the photoelectric properties of a laminated charge image carrier. In the process, a coating composition is prepared containing an insulating material which is doped by admixing a sensitizer and a coating of the doped composition is applied to a substrate to form a doped insulating layer. A photoconductive layer containing the sensitizer is then applied to the doped insulating layer.
    Type: Grant
    Filed: May 8, 1981
    Date of Patent: May 31, 1983
    Assignee: Elfotec A.G.
    Inventors: Hans Camenisch, Jarmila Bachner, Wolfgang F. Berg
  • Process for improving the photoelectric properties of a laminated charge image carrier
    Patent number: 4307166
    Abstract: A process for improving the photoelectric properties of a laminated charge image carrier. In the process, an insulating layer, which can be doped before or after application, is applied between the substrate and the photoconductive layer. The insulating layer can also be applied in layers, one of which can be doped. Suitable dopants are acid, alkaline and halogen vapors, sensitizers and pigments.
    Type: Grant
    Filed: February 3, 1975
    Date of Patent: December 22, 1981
    Assignee: Elfotec A.G.
    Inventors: Hans Camenisch, Jarmila Bachner, Wolfgang F. Berg
  • Process for electrographic image production and an apparatus for carrying out this process
    Patent number: 4240723
    Abstract: A process for a latent electrostatic image or a conductivity image on a photoconductor, a single-component magnetic toner being used for development and a magnetic brush being used not only for application of the toner to the image, but also for removal of residual toner. The brush may be one and the same brush for both tasks or separate brushes identical in structure may be used for each of the two tasks.
    Type: Grant
    Filed: May 16, 1975
    Date of Patent: December 23, 1980
    Assignee: Elfotec A.G.
    Inventor: Gabor Forgo
  • Process for electrophotographic image formation and transfer
    Patent number: 4210448
    Abstract: Sharp, high-resolution copies of electrostatc images developed with a one-component magnetic toner can be obtained by corona transfer to a copy sheet if toner resistivity is at least 10.sup.13 ohm-cms. Such resistivity is attainable by incorporating carbon within the toner particles in an amount preferably about 1 to 1.3 per cent by weight, the surface of the toner particles either not having any carbon thereon or it being present in amounts of at most 0.7 per cent by weight.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: July 1, 1980
    Assignee: Elfotec A.G.
    Inventor: Gabor Forgo
  • Procedure for making a reusable photoconducting charge image carrier and charge image carriers prepared by this method
    Patent number: 4191567
    Abstract: Long-life multilayer photoconductive members of the ZnO type are obtained when the successive layers are deposited using solvents, drying temperatures, etc. which do not affect the layers previously deposited. In such fashion, at least 4,000 cycles of use are possible.
    Type: Grant
    Filed: February 3, 1975
    Date of Patent: March 4, 1980
    Assignee: Elfotec A.G.
    Inventors: Hans Camenisch, Jarmila Bachner
  • Process and apparatus for developing and cleaning a charge image carrier
    Patent number: 4181422
    Abstract: A process for developing a latent charge image on a repeatedly usable charge image carrier and for cleaning the carrier after transfer of the developed charge image by means of a single magnetic brush having a layer of magnetic one-component toner and a thickening of the layer of toner in the region of contact of the magnetic brush with the charge image carrier.
    Type: Grant
    Filed: May 13, 1977
    Date of Patent: January 1, 1980
    Assignee: Elfotec A.G.
    Inventors: Gabor Forgo, Karl Moser