Patents by Inventor Joseph H. DiMatteo

Joseph H. DiMatteo 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).

  • Acquiring focus in optical systems using a focus error signal and a laser drive signal
    Patent number: 4998233
    Abstract: A focus acquire circuit for use in optical systems, such as optical data recorders and players, uses up to three parameters signals to indicate an in-focus condition. The zero crossing of a focus error signal is combined with a signal indicating that the focus error signal has approached a peak value and with a signal indicating a change in laser drive signal amplitude to indicate an in-focus condition. Various circuit details are illustrated showing how the three parameters cna be combined together for indicating an in-focus condition.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: March 5, 1991
    Assignee: International Business Machines Corporation
    Inventors: Joseph H. DiMatteo, Alan A. Fennema, Benjamin C. Fiorino, Julian Lewkowicz