Patents by Inventor Hendrik J. Sanderson

Hendrik J. Sanderson 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: 4364097
    Abstract: A two-head recorder in which information is read from recording tracks which are substantially parallel to each other and which make an angle with the longitudinal axis of a tape-like recording medium. The recorder comprises two heads which are each mounted on a transducer for moving the head as a function of tracking signals for the two heads which appear alternately so that the two heads are alternately centered relative to the recording track. The tracking signals are also applied to a tape speed control circuit in order to control the speed of the tape-like recording medium depending upon the average value of the tracking signals.
    Type: Grant
    Filed: May 30, 1980
    Date of Patent: December 14, 1982
    Assignee: U.S. Philips Corporation
    Inventors: Jacob De Boer, Hendrik J. Sanderson, Friedrich Sommer
  • Patent number: 4309730
    Abstract: Method and apparatus for positioning magnetic heads in a two-head helical scan video recorder, suitable control signals being generated for making the heads follow the tracks by means of piezoelectric transducers. The control signals applied to the two transducers are compared and when these control signals deviate from each other more than to a predetermined extent the one transducer receives the same control signal as the other transducer, so as to ensure that the two heads follow consecutive tracks.
    Type: Grant
    Filed: November 5, 1979
    Date of Patent: January 5, 1982
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik J. Sanderson
  • Patent number: 4306261
    Abstract: A method of recording information on a tape-like record carrier by means of a device provided with a rotary head disc on which a write head with controllable height is mounted for actively following the tracks. During recording tracking signals are written with the aid of a separate fixed head, which preferably also constitutes the erase head, and the write head follows the tracking signal recorded by the fixed head during the recording of information.
    Type: Grant
    Filed: October 11, 1979
    Date of Patent: December 15, 1981
    Assignee: U.S. Philips Corporation
    Inventors: Hendrik J. Bergmans, Hendrik J. Sanderson
  • Patent number: 4303953
    Abstract: In video recorders where the video information is alternately recorded in oblique tracks by means of two heads, there are generally provided fine control mechanisms for centering the heads relative to the track to be followed. These mechanisms do not detect whether the two heads occupy a correct position relative to each other so that their position relative to each other may differ by an amount corresponding to one track or a group of tracks. The disclosed method of controlling the two heads so that they occupy a correct position relative to each other assumes the use of a recording medium with signals reproduced by the heads contain pilot signals such that in the case of a correct reading of two consecutive tracks, the detected pilot signals are spaced at a nominal time interval from each other, i.e. half the revolution period of the head disk.
    Type: Grant
    Filed: July 18, 1979
    Date of Patent: December 1, 1981
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik J. Sanderson
  • Patent number: 4297733
    Abstract: Method and device for controlling the position of a write or read head, which covers adjacent tracks on a record carrier, relative to at least one adjacent track, which tracks in addition to the information signals contain tracking signals, the tracking signal in n consecutive tracks having n different frequencies, where n.gtoreq.4, and the difference of the frequencies of the tracking signals of every two adjacent tracks with the frequency of the third signal, which frequency may differ from track to track, always yielding fourth signals with the same pair of lower frequencies, a control signal being derived from said fourth signals.
    Type: Grant
    Filed: April 1, 1980
    Date of Patent: October 27, 1981
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik J. Sanderson
  • Patent number: 4237500
    Abstract: A method and apparatus for controlling the position of write-read heads with which information is recorded in a plurality of parallel tracks on a record carrier. In accordance with the invention a tracking signal is recorded in at least selected tracks during a first time interval. When the next track is written the supply of write signals to the write-read heads is interrupted for a second time interval, the first and second time intervals being selected in such a way that the track portions corresponding to said two time intervals adjoin each other. During the second time interval the cross-talk signal produced in the write-read head by the recorded tracking signal is measured and employed to produce a control signal for positioning the write-read heads.
    Type: Grant
    Filed: January 24, 1979
    Date of Patent: December 2, 1980
    Assignee: U.S. Philips Corporation
    Inventor: Hendrik J. Sanderson