Patents by Inventor W. R. Buchan

W. R. Buchan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5006869
    Abstract: The invention provides an electrostatic print cartridge for use in placing electrostatically charged dots on a charge receiving surface to build a latent image for subsequent toning. The cartridge includes a rigid spine to prevent the cartridge from bending during construction; a dielectric substrate attached to the spine with driver electrodes arranged in parallel lines between the spine and the dielectric substrate; and finger electrodes arranged on the opposite side of the substrate intersecting the driver electrodes and defining a matrix of apertures aligned with the intersection points of the driver and finger electrodes. The apertures in each finger electrode cover a segment of a complete image and are arranged so that the sequence of creating dots is such that primary dots are laid down separated from one another in each segment and subsequently secondary or intermediate dots are placed in spaces between the primary dots as the segment is filled with dots.
    Type: Grant
    Filed: November 8, 1989
    Date of Patent: April 9, 1991
    Assignee: Delphax Systems
    Inventors: W. R. Buchan, Robert S. McCallum