Patents Assigned to Comtech Research
  • Patent number: 4670364
    Abstract: The invention provides a master for use in image transfer by contact printing onto a transparent electrophotographic (TEP) film, which comprises an electrically insulating substrate having a planar surface which carries image elements deposited thereon; and a thin transparent insulating layer covering said planar surface and said image elements. The surface of the thin transparent insulating material is preferably profiled so that it comprises a base level and raised portions extending above said base level, the area of the raised portions being small compared to the total surface area of the transparent insulating layer. A thin transparent electrode may be incorporated between the substrate and the thin transparent insulating layer.Methods of forming such a master and of contact printing with it are also disclosed.
    Type: Grant
    Filed: May 31, 1985
    Date of Patent: June 2, 1987
    Assignee: Comtech Research Unit Limited
    Inventor: Victor C. Humberstone
  • Patent number: 4532197
    Abstract: A method of forming an image on an electrophotographic film material is described. This involves a contact printing technique and comprises the following steps:(a) placing an image-bearing master in contact with the film;(b) exposing the film to light through the image-bearing master, the exposure being substantially greater than the minimum necessary to render conductive the photo-conductive layer of the electrophotographic film;(c) applying a substantially uniform charge to the surface of the film in the dark immediately after exposure;(d) leaving the film in the dark for a short time so as to allow the charge to migrate selectively; and(e) then developing the image.
    Type: Grant
    Filed: May 17, 1983
    Date of Patent: July 30, 1985
    Assignee: Comtech Research Unit Limited
    Inventors: Victor C. Humberstone, John H. Fisher
  • Patent number: 4524116
    Abstract: The invention provides a master for use in image transfer by contact printing onto a transparent electrophotographic (TEP) film, which comprises an electrically insulating substrate having a planar surface which carries image elements deposited thereon; and a thin transparent insulating layer covering said planar surface and said image elements. The surface of the thin transparent insulating material is preferably profiled so that it comprises a base level and raised portions extending above said base level, the area of the raised portions being small compared to the total surface area of the transparent insulating layer. A thin transparent electrode may be incorporated between the substrate and the thin transparent insulating layer.Methods of forming such a master and of contact printing with it are also disclosed.
    Type: Grant
    Filed: May 17, 1983
    Date of Patent: June 18, 1985
    Assignee: Comtech Research Unit Limited
    Inventor: Victor C. Humberstone
  • Patent number: 4522482
    Abstract: An apparatus for recording information in the form of a two dimensional array of miniature images on a recording material such as electrophotographic, photographic or photochromic material. Means are included for forming those images (by such of the processes of sensitizing, charging, exposing, developing or fixing as are appropriate to the particular material used) from originals or copies of legible size. A facility is provided to form one or more miniature images occupying only part of a storage member on one occasion, and to record a further such image or images on later occasions. Guide means and propulsion means in two dimensions are included for adjusting the relative positions of the storage member and the image forming or image viewing device so that any image space may be presented to the image forming device and any image may be presented to an image viewing device.
    Type: Grant
    Filed: February 14, 1983
    Date of Patent: June 11, 1985
    Assignee: Comtech Research
    Inventors: Robert M. Pettigrew, John D. Bradbrook, Alan M. Smith, John H. Fisher