Patents by Inventor Seiichi Yokosawa

Seiichi Yokosawa 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: 4875115
    Abstract: A digital signal reproducing apparatus which reproduces digital PCM audio signals recorded on a recording medium in the form of single helical tracks. The apparatus is provided with at least two rotary heads for reproducing signals on the recording medium. The apparatus, however, is not provided with an erase head. Previously recorded signals are erased by overwriting, as a result of which a problem may arise in which a sync signal remains unerased. Therefore, a level of a pilot signal frequency component sampled in response to the sync signal is compared with a predetermined level to see if the sampled level is appropriate. It it is not appropriate, capstan servo control is not performed.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: October 17, 1989
    Assignee: Pioneer Electronic Corporation
    Inventor: Seiichi Yokosawa
  • Patent number: 4864436
    Abstract: In a digital audio recording/reproducing apparatus of the rotary head type, erasure of signals in previously recorded tracks, which are used to control the operation of a tracking servomotor, is enhanced by the provision of a magnetic field generator prior to the point where overwriting occurs. As a result, errors in the tracking error signal arising due to unerased remnants of the previously recorded signals are eliminated.
    Type: Grant
    Filed: September 21, 1987
    Date of Patent: September 5, 1989
    Assignee: Pioneer Electronic Corporation
    Inventors: Yutaka Masumoto, Tomoyasu Yamada, Seiichi Yokosawa
  • Patent number: 4860130
    Abstract: In a rotary head type digital audio signal reproducing apparatus such as an R-DAT or the like, disturbances in the operation of a capstan servo circuit due to erroneous detection of sync signals or interference caused by incompletely erased pilot signals are prevented. Differences between the levels of crosstalk of pilot signals from the two tracks adjacent the on-track being scanned are checked to see if they have a predetermined relationship with the level of the signal being currently supplied to the capstan servo. If this predetermined relationship is not satisfied, supply of the signal which represents the amount of track deviation to the capstan servo is inhibited.
    Type: Grant
    Filed: March 4, 1988
    Date of Patent: August 22, 1989
    Assignee: Pioneer Electronic Corporation
    Inventors: Seiichi Yokosawa, Ken-ichiro Kawasaki
  • Patent number: 4841390
    Abstract: A digital signal reproducing apparatus which reproduces digital PCM audio signals recorded on a recording medium in the form of single helical tracks. The signals recorded on the recording medium are reproduced by a rotary head. In order to prevent the erroneous detection of an ATF (Automatic Track Finding) signal, block addresses recorded in subcodes and PCM areas are read into a system counter which is used for forming a window for detecting ATF synch signals, and then the count value of the system counter is compensated for.
    Type: Grant
    Filed: October 5, 1987
    Date of Patent: June 20, 1989
    Assignee: Pioneer Electronic Corporation
    Inventor: Seiichi Yokosawa
  • Patent number: 4647985
    Abstract: A method for recording and reading out a video format signal includes steps of recording frequently used words, phrases, or sentences in an audio informations corresponding to video informations, in a frame before frames for video informations while being treated by time axis compression process, and recording remaining audio informations in desired frames among the frames for the video informations also while being treated by the time axis compression process. In the playback of the thus recorded audio informations, the frequently used part of the audio information is stored in a part of a memory device, and the remaining part of the audio information are stored in the remaining part of the memory device, and the stored audio informations are read out at need and combined with each other while being treated by the time axis expansion process.
    Type: Grant
    Filed: April 26, 1984
    Date of Patent: March 3, 1987
    Assignee: Pioneer Electronic Corporation
    Inventor: Seiichi Yokosawa