Patents by Inventor Frederik J. de Jong

Frederik J. de Jong 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).

  • Electronic flash unit
    Patent number: 4492451
    Abstract: An electronic flash unit having a thin-walled housing (2) in which is accommodated a reflector (3) with a discharge flash lamp (4) and which on the light-emanating side is provided with a photosensitive cell (6) for measuring a quantity of light reflected from an object to be photographed, which cell switches off the discharge flash lamp (4) by means of an electric circuit after measurement of a light dose.According to the invention, the wall of the housing (2) is provided with means, such as an upright edge (7), for receiving an end of a light-conducting fiber cable (9), which end is arranged in front of the photosensitive cell.
    Type: Grant
    Filed: July 5, 1984
    Date of Patent: January 8, 1985
    Assignee: U.S. Philips Corporation
    Inventors: Egbertus J. P. Maassen, Frederik J. de Jong