Patents by Inventor Johannes M. Ramaker

Johannes M. Ramaker 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).

  • Method of making a master disk used in making optical readable information disks
    Patent number: 4861699
    Abstract: A method of manufacturing an optical master disk, matrix derived from the master disk and synthetic resin information disk derived from the matrix.A method of manufacturing an optical master disk in which a supporting plate is provided on one side with at least two layers of a photosensitive material in which, taken from the supporting plate, the photosensitivity of the material of the layers increases and/or in which a light-absorbing separation layer is used between the layers, as well as a metal matrix derived from the master disk and an optically readable information disk of synthetic resin derived from the matrix.
    Type: Grant
    Filed: November 26, 1985
    Date of Patent: August 29, 1989
    Assignee: U.S. Philips Corporation
    Inventors: Jacob Wijdenes, Johannes M. Ramaker, Cornelis Weening