Patents Assigned to Hitachi Denshi Kabushiki
  • Electrode material for surface acoustic wave devices and surface acoustic wave device using the same
    Patent number: 4906885
    Abstract: A surface acoustic wave device has its inter--digital transducers made of a 3--metal alloyed material consisting of aluminum, copper and magnesium.
    Type: Grant
    Filed: September 21, 1988
    Date of Patent: March 6, 1990
    Assignees: Hitachi Denshi Kabushiki Kaisha, Hitachi, Ltd.
    Inventors: Hiroomi Kojima, Toyoji Tabuchi, Mitsutaka Hikita, Kazuhito Kurosawa, Atsushi Sumioka
  • Dynamic image correction method of offsets of various image pickup characteristics of a television camera system caused by variations in various image pickup conditions
    Patent number: 4827333
    Abstract: A method for dynamically correcting offsets of various pickup characteristics of a deflection system, a picture system and a mechanical system of a color television camera system in the course of an actual operation of the camera, so that the camera is maintained substantially under optimal picture shooting conditions. Selected components of the camera optical system, such as the pickup lens (optical systems), pickup devices and the like, are controlled by using as control parameters the iris value, zoom ratio, focal length and the like of the pickup lens, and image pickup conditions such as lighting conditions, surrounding temperature and time-dependent variation characteristics, and calculating exemplary correction values for correcting distortion of a pick-up image caused by the deflection system, picture system and mechanical systems.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: May 2, 1989
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Kuzuki Iwabe
  • Maximum likelihood decoder
    Patent number: 4823346
    Abstract: A maximum likelihood decoder for decoding a code from a signal transmitted through quadrature amplitude modulation of a code including a convolutional code can decode at high speed and high accuracy with a simple hardware configuration. In the maximum likelihood decoding of the convolutional code, the metric processing is not carried out for all of the possible paths and states but a smaller number of path(s) (metric(s)) and state(s) (metric(s)) are selected in a descending order to determine survival paths.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: April 18, 1989
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki
    Inventors: Naoya Kobayashi, Makoto Ohnishi, Yoshiro Kokuryo
  • Voltage-controlled oscillator
    Patent number: 4801898
    Abstract: A voltage-controlled oscillator includes a negative resistance generator, a resonant circuit, a first series circuit, a second series circuit, and a third series circuit. The first series circuit controls an oscillation frequency for changing a resonant frequency of the resonant circuit, and the second series circuit modulates this frequency. The third series circuit consists of a capacitor and a variable capacitance diode to which the modulation signal is supplied. The third series circuit changes the resonant frequency of the resonant circuit in a direction for cancelling a change in modulation sensitivity caused by the second series circuit.
    Type: Grant
    Filed: March 17, 1988
    Date of Patent: January 31, 1989
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Katsuki Obayashi
  • Circuit for detecting synchronizing code
    Patent number: 4802192
    Abstract: An original code series containing a synchronizing code is divided into code series, n in number so as to reduce an operation rate to 1/n (n is a positive integer). The detection of a synchronizing pattern is conducted on the basis of a fact that an original synchronizing pattern is transformed into any of patterns of n kinds based on the phase of division.
    Type: Grant
    Filed: February 10, 1987
    Date of Patent: January 31, 1989
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Yoshizumi Eto, Kazuyuki Takeshita, Hidehiro Kanada, Masuo Umemoto
  • Duplex radio communication transceiver
    Patent number: 4792939
    Abstract: In order to reduce the size of a duplex radio communication transceiver such as a mobile telephone, this transceiver is constructed of a transmitting and receiving duplexer, a filter to be coupled to the duplexer, an amplifier for amplifying a signal received, and a filter to be connected with the output of the amplifier. All the filters are made of acoustic surface wave filters, and all the circuits are mounted on a single metallic substrate and sealed by means of a metallic casing into a module. The transceiver thus constructed has a volume which is one tenth as small as that of the device of the same kind according to the prior art.
    Type: Grant
    Filed: January 23, 1987
    Date of Patent: December 20, 1988
    Assignees: Hitachi Denshi Kabushiki Kaisha, Hitachi Ltd.
    Inventors: Mitsutaka Hikita, Atsushi Sumioka, Yoshikatu Ishida, Kunihiro Hamada, Yutaka Chiba, Yoshio Abe
  • Digital signal recording and reproducing system having an interface for dubbing a color television signal in the component form
    Patent number: 4791495
    Abstract: A digital recording and reproducing system wherein luminance signals digitized and converted into the low speed signals and chrominance signals digitized at the time of recording are distributed among a plural number of channels and the signals of the plural number of channels are recorded respectively on a recording medium. At the time of the reproduction, the signals of the plural number of the channels are reproduced respectively from the recording medium and combined to form the luminance signals and the chrominance signals respectively. The luminance signals in the combined signal are converted into a high speed signal and output terminals for outputting dubbing signals from the system for dubbing the signals are led. The output side of a low speed-to-high speed converter and a channel combination circuit.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: December 13, 1988
    Assignees: Hitachi Denshi Kabushiki Kaisha, Hitachi Ltd.
    Inventors: Masuo Umemoto, Yoshizumi Eto, Shinichi Miyazaki, Hidehiro Kanada, Hitoshi Katayama, Yuichi Michikawa
  • Dubbing method and apparatus for digital recording reproducing apparatus including direct digital outputs
    Patent number: 4775897
    Abstract: Disclosed is an apparatus in which a picture signal is converted into digital signals and the digital signals are recorded into a recording medium, and which is suitable to perform dubbing of the digital signals reproduced from the recording medium. The apparatus employs the component method in which a luminance signal and chrominance signals constituting a picture signal are recorded separately from each other. According to the component method, the sampling frequency of the chrominance signal is set to be about 1/3-1/4 of that of the luminance signal, and therefore the recording/reproducing of a picture signal is carried out after the bit rate of the digital luminance signal is converted into a value equal to the bit rate of the digital chrominance signal.
    Type: Grant
    Filed: May 27, 1986
    Date of Patent: October 4, 1988
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Masuo Umemoto, Yoshizumi Eto, Shinichi Miyazaki, Hidehiro Kanada, Hitoshi Katayama, Yuichi Michikawa
  • Picture element arranging method in video data recording-reproducing system
    Patent number: 4764820
    Abstract: A video data recording/reproduction method used in a VTR, wherein distribution of picture elements into channels is altered for each field or frame so that the same picture element arrangement produced by interpolation does not continue in successive fields or frames, and wherein information indicating the type of picture element arrangement is recorded together with the video data. The method is intended to perform interpolative correction for still picture portions without sacrificing the resolution, while retaining the editing functions in units of field or frame, whereby degradation of a reproduced picture can be minimized.
    Type: Grant
    Filed: February 3, 1986
    Date of Patent: August 16, 1988
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Kazuyuki Takeshita
  • Adaptive digital filter
    Patent number: 4754419
    Abstract: In an adaptive digital filter having a digital filter for simulating a transmission system having indeterminate transmission characteristics through a series circuit of a plurality of series-connected delay circuits, and a correction circuit for correcting the output signal from the digital filter in accordance with changes in transmission characteristics of the transmission system, an input signal to and an output signal from the series circuit of the delay circuits are squared. The difference between the square signals is divided by the number of the delay circuits to obtain a mean value. When the mean value exceeds a predetermined value, the operation of the correction circuit is inhibited.
    Type: Grant
    Filed: October 21, 1985
    Date of Patent: June 28, 1988
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Yoshihiro Iwata
  • Frequency synthesizer with low power consumption
    Patent number: 4754235
    Abstract: A synthesizer apparatus includes a reference oscillator for generating a reference signal, a voltage controlled oscillator (VCO) whose oscillation frequency is controlled by a control signal, a frequency divider, which is intermittently operated, for frequency-dividing the output signal from the VCO, and a phase comparator for comparing the phases of the reference signal and the output signal from the frequency divider, and supplying a control signal to the VCO in accordance with the phase difference. The phase comparator outputs an average value signal having an average value corresponding to a difference in pulse rise times of the output signal from the frequency divider during an operation period of the frequency divider.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: June 28, 1988
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventor: Yukinari Fujiwara
  • Method for distributing and recording video signals and an apparatus using the same
    Patent number: 4737863
    Abstract: Video signal components including the luminance and color signals are sampled using a clock generator and dividers, and the resultant signals are coded through a plurality of channels and are recorded in a video tape recorder. In order to suppress and disperse in the screen image the effect of an error or a dropout occurring in a channel during a recording/playback process, the coded pixels are distributed to each channel so as to uniformly disperse the pixels associated with each component in the screen image. For this purpose, the pixels on a line perpendicular to the scanning lines on the screen are extracted sequentially from a different channel; consequently, even if a failure takes place in a channel, the erroneous pixel can thus be compensated for by use of the correct pixel just above or below the erroneous pixel.
    Type: Grant
    Filed: July 25, 1985
    Date of Patent: April 12, 1988
    Assignees: Hitachi, Ltd, Hitachi Denshi Kabushiki Kaisha
    Inventors: Yoshizumi Eto, Masuo Umemoto, Sinich Miyazaki
  • Surface acoustic wave resonator
    Patent number: 4734664
    Abstract: In order to realize an SAW filter withstanding high power, a plurality of single open-ended surface acoustic wave resonators are connected in series, and an earth conductor is disposed at least on a part of rear face of a piezoelectric substrate constituting the surface acoustic wave resonators. And static capacities formed between said earth conductor and electrode conductors on the piezoelectric substrate constituting the surface acoustic wave resonators are utilized as constituents of the filter circuit. In the above described structure, a part of input power is not converted into acoustic energy, but directly transmitted to the output side. Since the mechanical stress imposed upon the electrode material and the piezoelectric substrate is thus lightened, the SAW filter can withstand a large power signal.
    Type: Grant
    Filed: March 26, 1986
    Date of Patent: March 29, 1988
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki
    Inventors: Mitsutaka Hikita, Atsushi Sumioka, Yoshikatu Ishida
  • Multi-tube color TV camera in which linear and non-linear components of a registration error due to chromatic aberration of a lens are corrected with corresponding deflection correction signals
    Patent number: 4733296
    Abstract: The chromatic aberration of the lens of a multi-tube color TV camera is separated into a linear component and a non-linear component. Horizontal and vertical deflection correction waveforms are generated in accordance with these two components. These two correction waveforms are superimposed onto horizontal and vertical deflection waveforms employed to deflect electron beams in said camera tubes. A registration error caused by the chromatic aberration of the lens is corrected with high accuracy by employing these correction waveforms.
    Type: Grant
    Filed: February 18, 1986
    Date of Patent: March 22, 1988
    Assignee: Hitachi Denshi Kabushiki Kaisha & Hitachi
    Inventors: Masanori Honbo, Kenji Takahashi, Koji Kudo, Shusaku Nagahara
  • Apparatus for controlling the electron beam in a television camera tube
    Patent number: 4716468
    Abstract: A camera tube device for use in, for example, a television camera comprises a cathode emitting electrons, and a first grid and a second grid having respective apertures for converging the electrons emitted from the cathode into a fine electron beam. The aperture of the second grid is sufficiently smaller than that of the first grid and plays an important role for the formation of the electron beam. The electron beam scans a target carrying a charge pattern corresponding to the luminous intensity of an object. Voltages applied to the first and second grids are controlled so as to provide the electron beam quantity corresponding to the luminous intensity of the object forming the charge pattern of the target.
    Type: Grant
    Filed: April 23, 1986
    Date of Patent: December 29, 1987
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Masanori Maruyama, Kenji Takahashi, Koji Kudo, Masanori Hombaugh, Shusaku Nagahara
  • Cylindrical image pickup tube having electrostatic deflection electrodes formed of straight line pattern yokes
    Patent number: 4701668
    Abstract: A magnetic focusing and electrostatic deflecting image pickup tube comprises electrostatic deflection electrodes each constituted by a straight arrow pattern yoke composed of straight line segments arrayed in a linear zigzag pattern. The pattern yoke has a twist angle set at a value not greater than 105.degree.. An average value of angles formed by each upper apex and two lower apices adjacent to the upper apex of the zigzag pattern yoke with reference to the axis of the tube lies within a range of 116.degree. to 127.degree..
    Type: Grant
    Filed: May 27, 1986
    Date of Patent: October 20, 1987
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Kentaro Oku, Masakazu Fukushima, Hitomi Suzuki, Masanori Maruyama
  • Digital data playback system
    Patent number: 4700240
    Abstract: Number data affixed to individual digital data divided into a plurality of data blocks are sequentially read out from a recording medium to be used for determining the write-in positions of the digital data in a memory. For determining the write-in positions of the digital data, the number data of the next write-in position is estimated on the basis of the number data of the current write-in position. Judgment is made as to whether or not the number of times of continuous non-coincidence between the estimated number data and the successively read-out number data exceeds a predetermined setting, and, also judgment is made as to whether or not the number data read out each time falls within a predetermined range. Depending on the results of these judgments, one of the read-out number data and the estimated number data is selected to determine the next write-in position.
    Type: Grant
    Filed: November 5, 1985
    Date of Patent: October 13, 1987
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Masuo Umemoto, Yoshizumi Eto, Hidehiro Kanada, Morito Rokuda
  • Method and apparatus for generating error correction codes for digitized picture signal recording/reproducing
    Patent number: 4698811
    Abstract: An apparatus for recording or reproducing codes resulting from digitalizing a picture signal on or from a video tape recorder includes a device for correcting code error produced due to interference in the course of recording or reproducing process. The pixel codes succeeding to one another in time are divided to high-order and low-order bit-blocks, respectively, wherein the high-order bits are used to constitute a pseudo pixel code which is then added with a pixel error correcting code. The pixel code consisting of the high-order bits is added with a bit error correcting code before being recorded. In reproduction, error correction can be realized at higher rate with the aid of the correction codes to improve the quality of reproduced picture.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: October 6, 1987
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Yoshizumi Eto, Masuo Umemoto, Hidehiro Kanada, Seiichi Mita
  • Image distortion correcting apparatus for television camera combining global and local corrections
    Patent number: 4692804
    Abstract: An image distortion correcting apparatus for a television camera. In addition to an analogue correcting waveform, four corner independent distortion correcting waveforms are employed for rough adjustment together with a digital distortion correcting signal serving for fine adjustment. These waveforms are combined to be utilized for correcting image distortion from which the television camera suffers. A high-accuracy correction of image distortion can be accomplished with a circuit configuration of a small scale.
    Type: Grant
    Filed: February 24, 1986
    Date of Patent: September 8, 1987
    Assignee: Hitachi Denshi Kabushiki Kaisha
    Inventors: Akira Aoki, Fumio Ukigaya
  • Method of magnetically recording coded digital video signals and an apparatus therefor
    Patent number: 4670797
    Abstract: An improved 8-8 mpping table system in digitally and magnetically recording video signals. Video signals coded into natural binary codes consisting of 8 bits are converted into different binary codes consisting of 8 bits constituted by patterns in which a continuous number of the 1's or the 0's does not exceed a predetermined number. In these codes, the continuous number of the 1's or the 0's is so limited that a maximum magnetization interval is reduced in magnetically recording the signals. Therefore, erroneous code is prevented from occurring in reproducing the signals.
    Type: Grant
    Filed: February 19, 1985
    Date of Patent: June 2, 1987
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Masuo Umenoto, Seiichi Mita, Morishi Izumita, Yuuichi Michikawa, Morito Rokuda, Hitoshi Katayama, Hidehiro Kanada