Patents by Inventor Johannes B. J. Schelen

Johannes B. J. Schelen 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).

  • Integrated semiconductor circuit with polarity reversal protection
    Patent number: 5349489
    Abstract: An integrated semiconductor circuit for use in a low voltage (1.5-2 V) battery operated device is provided with a protection circuit against reverse connection of the battery.The protection circuit takes care that the substrate is always connected to one extreme potential and a region containing one or more resistors is always connected to the other extreme potential irrespective of the proper or reverse mode of connection of the battery. The protection circuit has been designed in such a way that no voltage drop occurs between the battery connections and the supply voltage connection terminals of the integrated semiconductor circuit.
    Type: Grant
    Filed: December 12, 1991
    Date of Patent: September 20, 1994
    Assignee: B.V. Optische Industrie "De Oude Delft"
    Inventor: Johannes B. J. Schelen
  • Device and method for controlling the contrast in an image observation system provided with an MCP image intensifier
    Patent number: 5341219
    Abstract: A device for determining a control signal for an image observation system including an image intensifier and an image converter wherein the control signal is representative of the contrast range of an output signal of the image converter and with control elements for adjusting the gain of the image intensifier and the gain of the image converter in a manner whereby the control signal at a value representative of a large contrast range in the output of signal of the converter results in higher adjustment gain of the image intensifier and a lower adjustment gain to the image converter and where the control signal at a value representative of a low contrast range in the output signal of the image converter results in lower adjustment gain to the image intensifier and higher adjustment gain to the image converter.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: August 23, 1994
    Assignee: B.V. Optische Industrie "De Oude Delft"
    Inventors: Johannes B. J. Schelen, J. van den Berg