Patents by Inventor Masahiko Achiha

Masahiko Achiha 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: 4970601
    Abstract: A video signal recording/reproducing apparatus for recording and reproducing a composite color television signal which is produced in such a manner that a modulated chrominance signal (namely, C-signal) is formed by modulating a color subcarrier with a color difference signal, and then superposed on a high frequency portion of a luminance signal (namely, Y-signal).
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: November 13, 1990
    Assignee: Hitachi, Ltd.
    Inventor: Masahiko Achiha
  • Patent number: 4821112
    Abstract: There is provided a detection circuit for TV receiver which includes a frame comb filter and a field comb filter and which generates a luminance signal or a chrominance signal by effecting addition or subtraction upon video signals of two frames adjoining each other included in the received TV signal. This detection circuit includes a synchronization separation circuit, an APC circuit, a frequency division circuit connected to the APC circuit, and a comparator circuit connected to the frequency division circuit. The frequency of the chrominance subcarrier signal is demultiplied by the frequency division circuit. The phase of the chrominance subcarrier signal thus frequency-divided is compared with the phase of the synchronizing signal separated by the synchronizing separation circuit. It is thus judged whether the received TV signal is a standard TV signal or a nonstandard TV signal.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: April 11, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Toshiyuki Sakamoto, Ikuya Arai, Toshiyuki Kurita, Toshinori Murata, Isao Nakagawa, Masahiko Achiha, Kazuo Ishikura
  • Patent number: 4811092
    Abstract: A movement detector necessary for processing composite color television signals, which detects movement in image signals, wherein the detecting circuit is so constructed that no deficient motion is produced. A difference signal between the present frame and that preceding by two frames of the television signals is converted into a motion information signal and a movement detection signal is made by integrating the signal obtained by the conversion with respect to temporal axis.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: March 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Achiha, Kazuo Ishikura, Shobu Saito, Masato Sugiyama, Kenji Katsumata
  • Patent number: 4794454
    Abstract: A movement detection circuit for detecting movement information of a luminance signal and movement information of a chrominance signal of a television signal comprises a first movement detection circuit for detecting the movement information of the luminance signal and a second movement detection circuit for detecting the movement information of the chrominance signal. The first movement detection circuit detects the movement information of the luminance signal based on two signals spaced by one frame period, and the second movement detection circuit detects the movement information of the chrominance signal based on two signals spaced by two frames periods.
    Type: Grant
    Filed: October 6, 1987
    Date of Patent: December 27, 1988
    Assignees: Hitachi, Ltd., Hitachi Video Engineering, Inc.
    Inventors: Masato Sugiyama, Kenji Katsumata, Shigeru Hirahata, Isao Nakagawa, Sunao Suzuki, Masahiko Achiha, Kazuo Ishikura
  • Patent number: 4775888
    Abstract: A motion detector for a chrominance signal which is used with a TV receiver equipped with a video signal motion detector. This motion detector for a chrominance signal has a delay element for delaying the chrominance signal of a video signal by 1 frame period, a subtracter for subtracting the output signal of the delay element from the input signal thereof, an absolute value conversion circuit to which the output signal from the subtracter is inputted, and a smoother circuit to which the output signal from the absolute value conversion circuit is supplied. If the chrominance signal of video signals on two consecutive frames are the same, the output signal of the subtracter becomes zero. If the chrominance signals of video signals on two consecutive frames are different, the output signal of the subtracter takes a positive or negative value. The negative value signal is converted into a positive value signal by the absolute value conversion circuit.
    Type: Grant
    Filed: January 13, 1988
    Date of Patent: October 4, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Isao Nakagawa, Masahiko Achiha, Masato Sugiyama, Kenji Katsumata, Toshinori Murata, Shigeru Hirahata, Akihide Okuda
  • Patent number: 4739390
    Abstract: A television signal processing circuit which separates a television signal into a luminance signal and a chrominance signal or interpolates the scanning lines of the television signal by using a video memory such as a frame memory or a field memory. The circuit determines whether the television signal to be treated is a standard television signal or a non-standard television signal. Depending upon this determination, the signal processing circuit changes its operation mode so that it operates properly even in case the television signal is different from the standard television signal and contains jitter in the time axis like the signal from a VTR. When the television signal is a non-standard television signal, the processing circuit without the video memory operates.
    Type: Grant
    Filed: August 12, 1986
    Date of Patent: April 19, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Achiha, Isao Nakagawa, Kazuo Ishikura, Shobu Saito
  • Patent number: 4736252
    Abstract: A motion detector for a chrominance signal which is used with a TV receiver equipped with a video signal motion detector. This motion detector for a chrominance signal has a delay element for delaying the chrominance signal of a video signal by 1 frame period, a subtractor for subtracting the output signal of the delay element from the input signal thereof, an absolute value conversion circuit to which the output signal from the subtractor is inputted, and a smoother circuit to which the output signal from the absolute value conversion circuit is supplied. If the chrominance signals of video signals on two consecutive frames are the same, the output signal of the subtractor becomes zero. If the chrominance signals of video signals on two consecutive frames are different, the output signal of the substractor takes a positive or negative value. The negative value signal is converted into a positive value signal by the absolute value conversion circuit.
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: April 5, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Isao Nakagawa, Masahiko Achiha, Masato Sugiyama, Kenji Katsumata, Toshinori Murata, Shigeru Hirahata, Akihide Okuda
  • Patent number: 4688084
    Abstract: Disclosed is a picture movement detection circuit for use for processing a color television signal, that is, a circuit for detecting temporal variations in chrominance signal level of a color televison picture. A signal corresponding to the magnitude of an absolute value, an amplitude, or the like, of a difference or addition signal between frames or field of a modulated chrominance signal of a color television signal is obtained, and a low frequency component is extracted out of the thus obtained signal so that the extracted low frequency component is used as movement information of the picture.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: August 18, 1987
    Assignee: Hitachi, Ltd.
    Inventor: Masahiko Achiha
  • Patent number: 4636857
    Abstract: A scanning line interpolation circuit for interpolating scanning lines of an interlaced television signal to thereby obtain a television signal having the doubled number of scanning lines, in which, in order to improve the quality of the reproduced television picture, the interpolation circuit is constituted by a spatio-temporal filter and a time compression circuit, and in the domain of the spatial vertical frequency and the time frequency, the total frequency characteristic of the spatio-temporal filter and the time compression circuit is set such that the response characteristic becomes zero at the vertical frequency and the time frequency of the scanning frequency of the interlaced television signal.
    Type: Grant
    Filed: January 8, 1985
    Date of Patent: January 13, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Achiha, Kazuo Ishikura
  • Patent number: 4626891
    Abstract: A motion detecting circuit suitable for detecting object-movement on an interlaced TV signal includes at least three field memories, subtracters, absolute circuits and an adder circuit. The motion detector evaluates object-movement by accumulating frame difference signals between adjacent fields.
    Type: Grant
    Filed: July 23, 1984
    Date of Patent: December 2, 1986
    Assignee: Hitachi, Ltd.
    Inventor: Masahiko Achiha
  • Patent number: 4530004
    Abstract: A color television signal processing circuit receives an input signal of a composite color television signal in the form of superimposition of a chrominance carrier signal on a luminance signal, separates the chrominance carrier signal and the luminance signal, and doubles the number of scanning lines of the chrominance signal or the luminance signal as compared to the number of scanning lines of the composite color television signal. A separation circuit separates the chrominance carrier signal and the luminance signal on the basis of a difference signal of the composite color television signal between adjacent frames or adjacent fields. A scanning line interpolation circuit doubles the number of scanning lines of at least the luminance signal delivered out of the separation circuit on the basis of an interpolation scanning signal derived from a signal indicative of scanning lines for the adjacent preceding field.
    Type: Grant
    Filed: December 29, 1982
    Date of Patent: July 16, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Masahiko Achiha, Kazuo Ishikura
  • Patent number: 4348689
    Abstract: A phase of a composite color television signal is adjusted by utilizing a signal which is one-field after or before relative to a current signal and which is a signal of the nearest scanning line. A difference signal between the color television signal and a signal derived from a one-field memory is applied to a band-pass filter and an output signal of the band-pass filter is added to the color television signal so that the phase of the carrier chrominance signal is adjusted by 180 degrees. The phase adjuster according to the present invention is applicable to video signal processing systems such as a noise reducer and a differential PCM coder.
    Type: Grant
    Filed: September 12, 1980
    Date of Patent: September 7, 1982
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventor: Masahiko Achiha
  • Patent number: 4296436
    Abstract: A noise reducer wherein, depending upon the magnitude of a difference signal between an input television signal at the present time and a television signal recorded in a frame memory and with noise reduced, the mixing ratio between the present-time input signal and the television signal obtained from the frame memory is varied, and a part of the mixed signal is applied to the frame memory while the other part is used as a television signal with noise reduced; a noise reducing system wherein, in order to make the reduction of noise possible even for a moving object, a movement of a picture in one frame time is detected, the output of the frame memory is compensated for with the movement, and depending upon the magnitude of a difference signal between the present-time input television signal and the movement compensated output signal of the frame memory, the mixing ratio between the present-time input television signal and the compensated output signal of the frame memory is varied.
    Type: Grant
    Filed: August 21, 1979
    Date of Patent: October 20, 1981
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventor: Masahiko Achiha
  • Patent number: 4295154
    Abstract: A digital video and audio file system is provided for use in systems such as a center-to-end video communication system. In the file system, video information, such as a color television video signal, is digitized in such a manner that it is separated into a luminance (Y) signal and a carrier chrominance (C) signal and these separated components are processed by the code differential method and the variable length encoding method. The digital signal thus digitized is recorded in a digital recorder. On the other hand, audio information is digitized by the AD-PCM encoding method and recorded in the same recorder. In encoding the video and the audio information, a part of hardware is used in common for both the signals, thus saving the hardware of the file system.
    Type: Grant
    Filed: August 3, 1979
    Date of Patent: October 13, 1981
    Assignees: Nippon Telegraph, Telephone Public Corp., Hitachi, Ltd.
    Inventors: Hidetoh Hata, Katsumi Haji, Kazushige Sako, Yoji Shibata, Masahiko Achiha