Patents by Inventor Isamu Misawa

Isamu Misawa 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: 5105417
    Abstract: In an apparatus for reproducing digital information recorded on a track in an optical record medium as discrete record portions representing bit "1" signals in the digital information, main and sub-reading light beams are projected on the optical record medium such that the sub-reading light beam is situated on the same track as that on which the main reading light beam is situated, but is shifted forwardly with respect to the main reading light beam relative to the scanning direction. The main and sub-reading light beams reflected by the optical record medium are photo-electrically converted into main and sub-reproduced signals, respectively. Peaks of the sub-reproduced signal are detected to derive a peak signal, and then the amplitude and offset of the peak signal are adjusted to produce a threshold signal. Alternatively, an average of the sub-reproduced signal is detected to derive an average value signal and the amplitude and offset of the average signal are adjusted to produce a threshold signal.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: April 14, 1992
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Akira Matsueda, Isamu Misawa