Patents by Inventor Alvin H. Armstrong

Alvin H. Armstrong 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).

  • Photographic printing and print identifying apparatus
    Patent number: 4193684
    Abstract: Photographic negatives or prints marked for identification purposes by exposure of the photographic record medium to a light image at a desired location by use of a contact printer having an opaque housing within which light is produced for a timed interval and projected through spaced diffuser elements, a masking element and an exposure window of the housing to form the light image.
    Type: Grant
    Filed: May 12, 1978
    Date of Patent: March 18, 1980
    Inventor: Alvin H. Armstrong