Patents by Inventor John C. Parker

John C. Parker 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: 4181863
    Abstract: Temperature regulation of an avalanche photodiode is obtained by internal heating, by passing a reverse current through the breakdown region of the photodiode. In operation, an empirically-derived, reverse bias potential, equal to the breakdown potential at the desired operating temperature, is applied; and when incident radiation is to be detected the reverse bias potential is temporarily lowered to an empirically-derived operating value.
    Type: Grant
    Filed: September 26, 1978
    Date of Patent: January 1, 1980
    Assignee: Ferranti Limited
    Inventor: John C. Parker
  • Patent number: 4066356
    Abstract: An anti-backlash means, particularly adapted for photographic enlargers including a channel shaped optical bench having a pair of guideways; a frame movable along the guideways, having a pair of tracks, a pair of rack elements, and leaf springs supporting the rack elements in continuous relation; a gear rotatably supported by the optical bench including a pair of gear elements engageable with the rack elements, and wheels riding on the tracks to maintain a fixed minor spacing between the pitch plane of the rack elements at the pitch radius of the gear elements; either the gear elements or the rack elements having offset teeth to eliminate backlash.
    Type: Grant
    Filed: October 7, 1976
    Date of Patent: January 3, 1978
    Assignee: Vivitar Corporation
    Inventor: John C. Parker