Patents by Inventor John R. Haglund

John R. Haglund 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).

  • Data recording system having improved bookkeeping capability
    Patent number: 5550684
    Abstract: A helical type tape recording and reproducing system records blocks of user data of predetermined size by reformatting the user data blocks into physical blocks that are recorded on tape. Each physical block is recorded as a double frame on a set of successive helical tracks, preferably 32 tracks. Each double frame has system format data interleaved with the user data. The present invention is directed to system format data that includes a sequence number for each physical block and enables the system to determine during reproducing if any physical block has been lost. The system also includes a partition access bookkeeping feature that stores information relating to locations at which searching or recording has been performed during a current load of a tape in the system, which is useful in accomplishing efficient searching for user data recorded on the tape.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: August 27, 1996
    Inventors: Lionel C. Shih, John R. Haglund
  • Data recording system having improved bookkeeping capability
    Patent number: 5442493
    Abstract: A helical type tape recording and reproducing system records blocks of user data of predetermined size by reformatting the user data blocks into physical blocks that are recorded on tape. Each physical block is recorded as a double frame on a set of successive helical tracks, preferably 32 tracks. Each double frame has system format data interleaved with the user data. The present invention is directed to system format data that includes a sequence number for each physical block and enables the system to determine during reproducing if any physical block has been lost. The system also includes a partition access bookkeeping feature that stores information relating to locations at which searching or recording has been performed during a current load of a tape in the system, which is useful in accomplishing efficient searching for user data recorded on the tape.
    Type: Grant
    Filed: February 28, 1992
    Date of Patent: August 15, 1995
    Assignee: Ampex Corporation
    Inventors: Lionel C. Shih, John R. Haglund