Patents by Inventor Joel Barnabas Chase

Joel Barnabas Chase 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).

  • Rotary encoder in which an absolute position is defined using reference mark signals produced by each of at least two readheads and method of operating the same
    Patent number: 8017904
    Abstract: Rotary encoder apparatus is described that comprises an encoder scale or ring and an encoder scale reader. The encoder scale includes an incremental scale and one or more reference marks. The encoder scale reader comprises at least a first readhead and a second readhead that each produce a reference mark signal when passed over a reference mark of the encoder scale. The apparatus also comprises a reference position setter for determining, as the encoder scale reader is rotated relative to the encoder scale, at least one angularly repeatable reference position of the encoder scale relative to the encoder scale reader using a first reference mark signal produced by the first readhead and second reference mark signal subsequently produced by the second readhead.
    Type: Grant
    Filed: January 17, 2007
    Date of Patent: September 13, 2011
    Assignee: Renishaw PLC
    Inventors: Joel Barnabas Chase, Thomas John Stickland, Peter Geoffrey Holden
  • Rotary Encoder Apparatus and Method
    Publication number: 20090072130
    Abstract: Rotary encoder apparatus is described that comprises an encoder scale or ring and an encoder scale reader. The encoder scale includes an incremental scale and one or more reference marks. The encoder scale reader comprises at least a first readhead and a second readhead that each produce a reference mark signal when passed over a reference mark of the encoder scale. The apparatus also comprises a reference position setter for determining, as the encoder scale reader is rotated relative to the encoder scale, at least one angularly repeatable reference position of the encoder scale relative to the encoder scale reader using a first reference mark signal produced by the first readhead and second reference mark signal subsequently produced by the second readhead.
    Type: Application
    Filed: January 17, 2007
    Publication date: March 19, 2009
    Applicant: RENISHAW PLC
    Inventors: Joel Barnabas Chase, Thomas John Stickland, Peter Geoffrey Holden