Patents by Inventor Mathias H. Geelen

Mathias H. Geelen 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: 4625326
    Abstract: An apparatus for generating a pseudo-stereo signal comprises at least two signal channels (3, 4), each signal channel (3) comprising a delay line (7) of which an output is fed back to the input (via g.sub.2). The delay lines (7, 8) have tappings (12, 13 and 14, 15 respectively). The tappings (12, 14 and 13, 15 respectively) are coupled to inputs of two signal-combination units (18 and 19, respectively) whose outputs (20, 21) are coupled to two output terminals (22, 23) to supply the pseudo-stereo signal (FIG. 1).
    Type: Grant
    Filed: November 5, 1984
    Date of Patent: November 25, 1986
    Assignee: U.S. Philips Corporation
    Inventors: Wilhelmus J. W. Kitzen, Mathias H. Geelen
  • Patent number: 4375623
    Abstract: An arrangement for the transmission of audio signals, comprising a delay line (1) provided with 5, 7 or 9 tappings situated at equal time intervals along the delay line. The tappings are each connected to a common adding circuit (16) via an amplitude control device (9 to 13). The ratios between the amplitudes of the output signals of the amplitude control devices, viewed from one end of the delay line (1) to the other end are 1:2n:2n.sup.2 :-2n:1 for five tappings, 1:2n:2n.sup.2 :n.sup.3 -n:-2n.sup.2 :2n:-1 for seven tappings, and 1:2n:2n.sup.2 :n.sup.3 -n:1/4(n.sup.4 -1)-2n.sup.2 :-(n.sup.3 -n):2n.sup.2 :-2n:1 for nine tappings. This yields an arrangement having a flat frequency response from the input (2) to the output (15). The invention also relates to a plurality of delay lines (for example 31 to 35) connected in series and to a reverberation unit provided with such a transmission arrangement.
    Type: Grant
    Filed: February 23, 1981
    Date of Patent: March 1, 1983
    Assignee: U.S. Philips Corporation
    Inventors: Nico V. Franssen, deceased, by Friedrich J. de Haan, administrator, Kornelis A. Immink, Eise C. Dijkmans, Mathias H. Geelen
  • Patent number: 4221928
    Abstract: Noise reduction circuit for stereo signals comprising a control input terminal, first and second outputs as well as a controllable coupling circuit for a controllable mutual signal coupling between the two outputs, the two outputs being decoupled from one another only during those sound passages wherein an effective after-effect of a stereo impression is produced to obtain an optimal combination of noise level and stereo effect.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: September 9, 1980
    Assignee: U.S. Philips Corporation
    Inventors: Nico V. Franssen, Mathias H. Geelen