Patents by Inventor Tadao Udagawa

Tadao Udagawa 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: 4396955
    Abstract: In a recording apparatus for performing magnetic recording onto different parts of a magnetic recording medium as it runs in sequence, a switching element is connected in series in a signal path to a magnetic head which is connected to the output of the signal amplifier and to a bias oscillator. Accordingly, the signal current flowing to the magnetic head can be interrupted. A delay circuit is provided for controlling the operation of the switching element so as to defer initiation of the signal current flow to the magnetic head. This is done pending attainment of the speed of movement of the magnetic recording medium to a substantially constant level after the magnetic recording starts. Connected in parallel to the switching element is a by-pass circuit of which the impedance is relatively low at a frequency equal to that of the bias supplied to the magnetic head. A stabilized muting effect from the low to the high sound region thus can be produced.
    Type: Grant
    Filed: June 19, 1981
    Date of Patent: August 2, 1983
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yutaka Kohtani, Tadao Udagawa