Patents by Inventor Catherine S. Singer

Catherine S. Singer 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).

  • System for predicting laser end-of life from the power vs. current curve of the diode
    Patent number: 5172365
    Abstract: Method and apparatus for predicting the approach of semiconductor laser diode end-of-life from the power vs. current characteristic curve of the diode thereby obviating the need for nonvolatile memory. Current measurements are taken for three power levels and the linear slope of the characteristic curve at the high power level is compared to the linear slope at low power levels. When the comparison exceeds predetermined criteria, a flag is raised.
    Type: Grant
    Filed: September 11, 1991
    Date of Patent: December 15, 1992
    Assignee: International Business Machines Corporation
    Inventors: David E. Call, Blair I. Finkelstein, Catherine S. Singer