Patents by Inventor Ronald T. Robertson

Ronald T. Robertson 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: 5109183
    Abstract: A high pressure sodium discharge lamp having an arc tube mounted within a lamp envelope and having a resistor connected electrically in series with the arc tube. An insulative body is provided between the arc tube feed-through closest to the stem and a rigid conductor for axially supporting the arc tube and electrically insulating the feed-through from the rigid conductor. The series flicker-elimination resistor is mounted adjacent the lamp stem and electrically shunts the insulative body. An integral thick film resistor which includes the series resistor and a starting resistor for a starting circuit has optimized terminal placement for simplifying mount construction.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: April 28, 1992
    Assignee: U.S. Philips Corporation
    Inventors: Ronald T. Robertson, Kenneth E. Pearson