Patents by Inventor Leonardus M. H. E. Driessen

Leonardus M. H. E. Driessen 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: 5754846
    Abstract: A topological network, comprising a set of 0-cells (nodes) (28, 29) interconnected by a set of 1-cells (aa, bb, . . . , gg).sub.1 is divided into sections (E, F, G) corresponding to discrete parcels of data for storage in a mass memory such as a CD-ROM. A boundary node (28, 29) is defined at each point where the network traverses a boundary between sections. The parcel of data for a given section includes a chain list record for each 1-cell in the section, which chain list record generally refers directly (TP) to a further 1-cell in the network terminating at the same node. However, no chain list record refers directly to a 1-cell outside the section of the network to which the data parcel relates. An indirect reference (0-C') across the section boundary can be made easily, while an overall saving in data volume is obtained compared with a known method.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: May 19, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Cornelis P. Janse, Leonardus M. H. E. Driessen
  • Patent number: 4954986
    Abstract: A method of storing in a memory digital data representing a topological network having a set of nodes (0-cells), segments (1-cells), and areas (2-cells) within concatenated 1-cells. For each 1-cell there are stored an associated first 0-cell and second 0-cell and also a thread pointer assigned to the 0-cells. The thread pointer of an 0-cell indicates the next-following 1-cell obtained by rotating the 1-cell in question in a predetermined direction of rotation around such 0-cell. For finding a 2-cell, use is made of a first 1-cell and the thread pointer associated with one of its 0-cells is followed after which, starting from the newly found 1-cell, each time the thread pointer of the opposite 0-cell is used until the first 1-cell is found again.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: September 4, 1990
    Assignee: U.S. Philips Corporation
    Inventors: Leonardus M. H. E. Driessen, Cornelis P. Janse
  • Patent number: 4888698
    Abstract: A database is stored in a mass memory. For this purpose, it is first divided into main cells and then into base cells according to a predetermined regular division pattern. Each base cell is then checked to see whether its data content is sufficient to occupy substantially completely a storage parcel having a predetermined capacity. If this is the case, the base cell is thus accommodated in a storage parcel; if this is not the case, adjacent base cells are grouped until a storage parcel is occupied substantially completely. The operation of addressing a storage parcel is effected by the use of a main cell table in which address pointers are stored, each of which points to a base cell table. In the base cell table, an index is given for each base cell and this index indicates in which storage parcel the relevant base cell is accommodated.
    Type: Grant
    Filed: October 19, 1987
    Date of Patent: December 19, 1989
    Assignee: U.S. Philips Corporation
    Inventors: Leonardus M. H. E. Driessen, Cornelis P. Janse, Paul D. M. E. Lahaije
  • Patent number: 4683572
    Abstract: For the decoding of a data stream which is word-wise protected against errors by a double Reed-Solomon code with symbol-wise interleaving over the code words, first the reliability information for the constituent symbols is aggregated for a code word. Therefrom the strategy is determined, entailing the number of erase symbols and the maximum number of error symbols to be corrected. The correction result is compared with a reliability code and on the basis thereof all symbols obtain an at least trivalent secondary reliability indication for decoding in the second code.
    Type: Grant
    Filed: September 24, 1984
    Date of Patent: July 28, 1987
    Assignee: U.S. Philips Corporation
    Inventors: Constant P. M. J. Baggen, Leonardus M. H. E. Driessen, Rudy W. J. Pollen, Lodewijk B. Vries
  • Patent number: 4675869
    Abstract: A decoding device for code words which are protected against the occurrence of several symbol errors per code word by means of a Reed-Solomon code is provided with a word buffer which comprises a space for the storage of an erasure indication per symbol received. For correction of the code word, first the syndrome symbols are formed by multiplication by the parity check matrix. The sum of twice the number of error symbols and once the number of erasure symbols may not be larger than the number of syndrome symbols. First the syndrome symbols are modified so that the syndrome symbols which could possibly relate to error symbols (non-erasure symbols) are no longer influenced by the erasure symbols. The key equation and error locator equation for the non-influenced syndrome symbols can then be separately solved, so that the locations of error symbols can be found.
    Type: Grant
    Filed: February 26, 1985
    Date of Patent: June 23, 1987
    Assignee: U.S. Philips Corporation
    Inventor: Leonardus M. H. E. Driessen
  • Patent number: 4567518
    Abstract: An error protection code which acts on subpictures for the transmission of television picture information. First the picture is subpicture-wise transformed (124) by means of transformation functions, for example, Hadamard functions. Of the coefficients thus formed, a number of most significant coefficient bits which are associated with low frequency transformation functions are protected against a bit error (126). Moreover, a comparatively small number of coefficient bits within said number are protected against an additional bit error.
    Type: Grant
    Filed: June 27, 1985
    Date of Patent: January 28, 1986
    Assignee: U.S. Philips Corporation
    Inventor: Leonardus M. H. E. Driessen
  • Patent number: 4555729
    Abstract: An error protection code which acts on subpictures together constituting a television picture for the transmission of data for reconstructing the television picture at the receiving end. First each subpicture transformed by, Hadamard functions. Of the coefficients thus formed, a number of most significant coefficient bits which are associated with low frequency transformation functions are protected against a bit error. Moreover, a comparatively small number of coefficient bits within said number are protected against an additional bit error.
    Type: Grant
    Filed: December 20, 1982
    Date of Patent: November 26, 1985
    Assignee: U.S. Philips Corporation
    Inventor: Leonardus M. H. E. Driessen