Patents by Inventor Christopher P. Bartram

Christopher P. Bartram 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: 5162862
    Abstract: Time of transit of a propagated electric signal at lightspeed is used as a measure of distance from a transmitter (laser 32) to a receiver (photodetector 39) via a target (reflector 14). A continuous modulating signal of fixed frequency (10.700 MHz) is transmitted. The distance traversed is measured by a timer which compares the phase at transmission with that at reception. The invention involves a heterodyne down-conversion technique involving two crystal oscillators (30, 31), which are phase-locked to assure that one regulates the other to keep their frequencies in linear proportional relationship, both being at the transmitter location, which transfer the phase difference to a 10.45 kHz frequency, thereby facilitating high resolution and precision mesurement by extending the time measure representing distance.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: November 10, 1992
    Assignee: Optical Metrology Limited
    Inventors: Christopher P. Bartram, John S. Strachan