Patents by Inventor Tadahiko Sakamoto

Tadahiko Sakamoto 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: 7406128
    Abstract: An orthogonal frequency division multiplexed signal generator comprises a data sequence conversion means, a power changing means, an inverse discrete Fourier transform part, and an orthogonal modulation means, and modulates a first data and a second data using modulation systems independent of each other, into an orthogonal frequency division multiplexed signal. The data sequence conversion means arranges the first data to be transmitted, in a predetermined order correspondingly to two or more sub-carriers orthogonal to each other on a frequency axis. The power changing means changes powers of the sub-carriers in accordance with the second data to be transmitted which is independent of the first data. The inverse discrete Fourier transform means generates a time-base waveform by synthesizing the individual sub-carriers. The orthogonal modulation means performs orthogonal modulation on a real axis signal and an imaginary axis signal which are orthogonal to each other to synthesize them.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: July 29, 2008
    Assignee: D&M Holdings Inc.
    Inventor: Tadahiko Sakamoto
  • Publication number: 20050002463
    Abstract: An orthogonal frequency division multiplexed signal generator comprises a data sequence conversion means, a power changing means, an inverse discrete Fourier transform part, and an orthogonal modulation means, and modulates a first data and a second data using modulation systems independent of each other, into an orthogonal frequency division multiplexed signal. The data sequence conversion means arranges the first data to be transmitted, in a predetermined order correspondingly to two or more sub-carriers orthogonal to each other on a frequency axis. The power changing means changes powers of the sub-carriers in accordance with the second data to be transmitted which is independent of the first data. The inverse discrete Fourier transform means generates a time-base waveform by synthesizing the individual sub-carriers. The orthogonal modulation means performs orthogonal modulation on a real axis signal and an imaginary axis signal which are orthogonal to each other to synthesize them.
    Type: Application
    Filed: August 3, 2004
    Publication date: January 6, 2005
    Inventor: Tadahiko Sakamoto
  • Patent number: 6816453
    Abstract: An orthogonal frequency division multiplexed signal generator comprises a data sequence conversion means, a power changing means, an inverse discrete Fourier transform part, and an orthogonal modulation means, and modulates a first data and a second data using modulation systems independent of each other, into an orthogonal frequency division multiplexed signal. The data sequence conversion means arranges the first data to be transmitted, in a predetermined order correspondingly to two or more sub-carriers orthogonal to each other on a frequency axis. The power changing means changes powers of the sub-carriers in accordance with the second data to be transmitted which is independent of the first data. The inverse discrete Fourier transform means generates a time-base waveform by synthesizing the individual sub-carriers. The orthogonal modulation means performs orthogonal modulation on a real axis signal and an imaginary axis signal which are orthogonal to each other to synthesize them.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: November 9, 2004
    Assignee: Denon, Ltd.
    Inventor: Tadahiko Sakamoto
  • Patent number: 6650600
    Abstract: A digital audio disc recorder improves the ability to carry out an editing operation easily and efficiently. A group of keys used for recording and reproduction operations, ten keys and a track selecting key group are arranged on the side of a panel face of a remote commander. Further, audio signals recorded in the editing operation are displayed as a plurality of materials, a jog dial for moving forwardly and rearwardly the plural materials of the displayed audio signals in a time axis direction is arranged on the side of a panel face of the remote commander, a group of keys for selecting the materials are arranged on the depth side, and a group of keys for instructing a method of processing the selected materials are arranged on the depth side.
    Type: Grant
    Filed: November 15, 2000
    Date of Patent: November 18, 2003
    Assignee: Denon, Ltd.
    Inventors: Kazuhisa Machida, Atsushi Ishibashi, Tsugio Endou, Tadahiko Sakamoto, Hideki Ikeda, Atsushi Oonishi
  • Patent number: 6600700
    Abstract: Disclosed is a digital audio disk recorder with improved ease of use, which can easily and efficiently superimpose a take of a short sound during broadcasting. In order to output takes of a plurality of short sounds, buttons “Key Name” corresponding to the takes of the sounds are displayed on a display screen for monitoring a state of broadcasting. By operating any of the buttons during broadcasting of a program for broadcasting displayed as a play list, the take of the short sound assigned to the button can be superimposed on a signal being broadcasted.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: July 29, 2003
    Assignee: Denon, Ltd.
    Inventors: Kazuhisa Machida, Atsushi Ishibashi, Tsugio Endou, Tadahiko Sakamoto, Hideki Ikeda, Atsushi Oonishi
  • Patent number: 6515948
    Abstract: It is intended to prevent occurrence of rotation lock waiting times when a simultaneous recording and reproducing operation is performed on a disc-shaped recording medium according to the ZCLV scheme. In a period when audio data of one data block are input to a recording buffer at a constant rate via an A/D converter, another data block that was input immediately before is recorded on and reproduced from an optical disc. Audio data constituting the reproduced data block are temporarily stored in a reproduction buffer and then read out at the constant rate and output via a D/A converter. A system controller performs control so that data blocks are recorded on the optical disc successively. As for a data block that is recorded in two adjacent zones, the system controller performs control so that the same data block that is read from the recording buffer, rather than the data block that has been recorded on the optical disc, is reproduced.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: February 4, 2003
    Assignee: Denon, Ltd.
    Inventor: Tadahiko Sakamoto
  • Patent number: 6314083
    Abstract: The present invention provides a frequency control device for following frequency deviation of OFDM (Orthogonal Frequency Division Multiplexing). On metrics obtained by discrete Fourier transform by a discrete Fourier transform section 1200, calculation is performed to decide which direction, upward or downward, a center of the energy distribution of the obtained metrics deviates from a theoretical center of frequency, to obtain a frequency difference, and an AFC signal in accordance with the frequency difference is generated in the control signal generating section 1350.
    Type: Grant
    Filed: April 2, 1998
    Date of Patent: November 6, 2001
    Assignee: Nippon Columbia Co., Ltd.
    Inventors: Takurou Kishimoto, Tadahiko Sakamoto