Patents by Inventor Robertus A. J. Keyser

Robertus A. J. Keyser 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 HID reflector lamp with HID arc tube in a pressed glass reflector retained in a shell housing a ballast
    Patent number: 6111359
    Abstract: An integrated reflector lamp includes a sealed envelope enclosing a high pressure gas discharge device. A shell has a rim portion which receives the sealed envelope and an opposing basal portion carrying a screw base. A ballast for igniting and operating the discharge device is enclosed within the shell between the screw base and the sealed envelope. The sealed envelope includes a reflective surface which directs light emitted by the discharge device. The reflective surface also provides effective heat management for preventing overheating of the ballast by the heat generated by the discharge device. The integrated lamp has photometrics and luminous efficacy which exceeds that of corresponding halogen and halogen IR reflector lamps while having an overall planform which fits within that of the corresponding lamp.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: August 29, 2000
    Assignee: Philips Electronics North America Corporation
    Inventors: Dale Work, Mark Fellows, Gregory Nelson, Kent Collins, Robertus A. J. Keyser, Andrew Jackson, Oscar J. Deurloo, Aswin J. G. Linden, Peter A. Seinen, Willem J. Van Den Hoek, Hendrik A. Van Esveld, Josephus C. M. Hendricx
  • High frequency HID lamp system
    Patent number: 5998939
    Abstract: A high pressure gas discharge lamp system includes a high pressure discharge lamp selected to have a lowest lamp resonant frequency above the audible, on a current basis above about 19 kHz and on a power basis of above about 38 kHz. The ballast circuit energizes the discharge device so as to have a fundamental frequency below the lowest lamp resonant frequency and above the audible, while keeping the magnitude of any harmonics above the lowest lamp resonant frequency sufficiently small so as to avoid acoustic resonance. By operating below the lowest lamp resonant frequency, greatly simplifying ballast construction and cost. According to one embodiment, the discharge vessel encloses a discharge space which is circular cylindrical and having a L:ID ratio of about 1:1 to maximize the lowest lamp resonant frequency.
    Type: Grant
    Filed: June 4, 1998
    Date of Patent: December 7, 1999
    Assignee: Philips Electronics North America Corporation
    Inventors: Mark Fellows, Gregory Nelson, Robertus A. J. Keyser, Dale E. Work, Josephus C. M. Hendricx, Oscar J. Deurloo, Aswin J. G. Linden, Peter A. Seinen, Andrew Jackson
  • High frequency HID lamp system with lamp driven at a frequency above the audible and below the lowest lamp resonant frequency
    Patent number: 5828185
    Abstract: A high pressure gas discharge lamp system includes a high pressure discharge lamp selected to have a lowest lamp resonant frequency above the audible, on a current basis above about 19 kHz and on a power basis of above about 38 kHz. The ballast circuit energizes the discharge device so as to have a fundamental frequency below the lowest lamp resonant frequency and above the audible, while keeping the magnitude of any harmonics above the lowest lamp resonant frequency sufficiently small so as to avoid acoustic resonance. By operating below the lowest lamp resonant frequency, greatly simplifying ballast construction and cost. According to one embodiment, the discharge vessel encloses a discharge space which is circular cylindrical and having a L:ID ratio of about 1:1 to maximize the lowest lamp resonant frequency.
    Type: Grant
    Filed: May 9, 1996
    Date of Patent: October 27, 1998
    Assignee: Philips Electronics North America Corporation
    Inventors: Mark Fellows, Gregory Nelson, Robertus A. J. Keyser, Dale E. Work, Josephus C. M. Hendricx, Oscar J. Deurloo, Aswin J. G. Linden, Peter A. Seinen, Andrew Jackson