Patents by Inventor Tatsushi Bannai

Tatsushi Bannai 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: 4839744
    Abstract: Disclosed is a video signal recording system, in which the input video signal is rid of unneeded portions, transformed on the time axis and divided into n channels so that they are recorded in a bandwidth narrower than 1/n of original one. The system also enhances the latitude in choosing a clock frequency for time-axis conversion and a track width, thereby optimizing the picture quality and recording time length on a trade-off basis.
    Type: Grant
    Filed: August 28, 1987
    Date of Patent: June 13, 1989
    Assignees: Nippon Hoso Kyokai, Matsushita Electric Industrial Co., Ltd.
    Inventors: Seishi Sasaki, Shigeru Awamoto, Tatsushi Bannai, Katsuya Yokoyama, Hiromichi Shibaya
  • Patent number: 4807056
    Abstract: A video signal recording and playback apparatus and method which is applicable to wide-band recording in which a video signal is divided into a plurality of channels by time-axis expansion, and the channels are recorded in parallel on respective tracks. Prior to recording, a reference signal consisting of a plurality of different signal bursts, each having a specific frequency and each being superimposed on a specific DC level, is inserted into blanking intervals of the video signal and recorded therewith. On playback, the amplitudes of the signal bursts in the reference signal are monitored, and playback equalizers are controlled accordingly such as to maintain a predetermined equalizer characteristic and to maintain identical overall frequency characteristics for the various channels.
    Type: Grant
    Filed: April 2, 1987
    Date of Patent: February 21, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Seishi Sasaki, Mitsuo Chiba, Tatsushi Bannai, Shigeru Awamoto
  • Patent number: 4757392
    Abstract: A signal processing circuit for a video recording and reproducing apparatus comprises a ramp inserting circuit for inserting a ramp waveform at periodic intervals into a video signal during recording. The ramp waveform varies linearly as a function of time from the minimum to the maximum level of the video signal. On playback, the inserted ramp is periodically detected from a reproduced video signal by a ramp detector. The waveform of the detected ramp is corrected to improve its signal-to-noise ratio by an averaging circuit and applied to a transfer circuit having a transfer function describing the relationship between the original ramp waveform and the corrected ramp waveform. The waveform of the reproduced video signal is transformed according to the transfer function.
    Type: Grant
    Filed: July 11, 1986
    Date of Patent: July 12, 1988
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shigeru Awamoto, Tatsushi Bannai