Patents Assigned to Akai Electric Co., Ltd.
  • Patent number: 5636076
    Abstract: After an audio signal at a given level is recorded, the recording level is changed and a video signal is recorded. The audio and video signals are reproduced. A first recording level at which the reproduced video signal becomes the maximum level, a second recording level which is smaller than the first recording level and at which the reproduced video signal level becomes the maximum value.times.0.9, a third recording level at which the reproduced audio signal level is equal to or greater than a reference value, and a fourth recording level at which the reproduced audio signal level becomes equal to or greater than the minimum value are stored in storages, respectively. The video head recording current value is controlled according to the optimum recording level found by an arithmetic section based on the stored recording levels.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: June 3, 1997
    Assignee: Akai Electric Co., Ltd.
    Inventors: Tokuichi Minakawa, Shinji Tanimoto
  • Patent number: 5581142
    Abstract: A vibration control apparatus capable of setting the frequency of self-oscillating or self-induced vibration of an oscillator to a frequency in near agreement with the mechanical series resonance frequency f.sub.s is provided. The apparatus comprises a vibrator having a single piezo-electric element on the side surface of a vibrator member having a resonance point, drive apparatus having signal output terminal that outputs the drive signal of vibrator, and feedback amplifier having signal input terminal and feedback input terminal. The signal input terminal of feedback amplifier is connected to signal output terminal of drive apparatus. The feedback input terminal is connected to one electrode of piezo-electric element. The other electrode of piezo-electric element is connected to ground.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: December 3, 1996
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5554904
    Abstract: A vibration control apparatus that can impart stabilized self-induced vibration without amplitude changes even under changes in ambient temperature is disclosed. When the apparatus is used with a vibrating gyroscope, detection accuracy is increased without temperature dependence of detection sensitivity on input angular velocity. The vibration control apparatus imparts self-induced vibration to a vibrator which has a pair of piezo-electric elements on the side surface of a vibration member having a resonance point. The vibrator is given self-induced vibration while the combined current value of the respective currents flowing through the pair of piezo-electric elements is held fixed. A drive signal output circuit outputs a drive signal applied to the pair of piezoelectric elements and has a voltage gain with a temperature dependence corresponding to the temperature dependencies of the equivalent resistances of the vibrator.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: September 10, 1996
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5551292
    Abstract: An angular velocity detection circuit is capable of detecting angular velocity at good efficiency, while also being capable of suppressing the formation of offset to very low amounts even when differences arise in the equivalent resistances of a piezo-electric pair. The vibrator has at least one pair of piezo-electric elements on the side surface of a vibration member having a resonance point. A detection circuit detects differences in the currents flowing through the piezo-electric elements under the resonance state of the vibrator. A sample and hold circuit samples and holds the output of the detection circuit at a time where the displacement velocity of the vibrator becomes zero. The angular velocity is detected based on the output of this sample hold circuit.
    Type: Grant
    Filed: January 10, 1995
    Date of Patent: September 3, 1996
    Assignee: Akai Electric Co., Ltd.
    Inventors: Kokichi Terajima, Shinichi Aotsu
  • Patent number: 5460043
    Abstract: A vibrating gyroscope comprises a vibrating element which is polygonal, e.g., rectangular, in cross-section, at least two piezoelectric elements adhered to at least one side of the vibrating element, and a variable resistor. The variable resistor includes at least two fixed terminals and a variable terminal for varying the resistance of the variable resistor. The piezoelectric elements are connected to the two fixed terminals of the variable resistor, while the variable terminal is grounded. This brings the output voltages generated by the piezoelectric elements into phase thereby improving measurement of angular velocity. In a preferred embodiment, a fixed resistor is disposed between the variable terminal of the variable resistor and the ground potential.
    Type: Grant
    Filed: September 16, 1992
    Date of Patent: October 24, 1995
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5446539
    Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a
    Type: Grant
    Filed: March 4, 1994
    Date of Patent: August 29, 1995
    Assignee: Akai Electric Co., Ltd.
    Inventor: Tokuichi Minakawa
  • Patent number: 5416641
    Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: May 16, 1995
    Assignee: Akai Electric Co., Ltd.
    Inventor: Tokuichi Minakawa
  • Patent number: 5400149
    Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: March 21, 1995
    Assignee: Akai Electric Co., Ltd.
    Inventor: Tokuichi Minakawa
  • Patent number: 5386726
    Abstract: A vibratory gyroscope comprises, with respect to an XYZ coordinate system, a tuning fork having two arm members extending from a base member in the direction of the Z-axis, a support member extending from the base member in the direction of the Z-axis, and a pickup member which senses a Coriolis force acting on the two arm members when they are caused to vibrate. The pickup member includes a layer of piezoelectric material polarized in the direction of the Z-axis and at least one pair of electrodes disposed on surfaces of the support member which are in parallel to the Z-axis. At least one of the electrodes is positioned to one side of a center line on its respective surface, the center line being parallel to the Z-axis. In one embodiment, the pickup member itself constitutes the support member of the tuning fork. In another embodiment, the pickup member is a separate unit which is affixed to a surface of the support member of the tuning fork.
    Type: Grant
    Filed: October 2, 1990
    Date of Patent: February 7, 1995
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5270607
    Abstract: A vibration control apparatus comprises a vibration member having a surface with a resonance point. A piezoelectric element is adhered to the surface of the vibration member. A drive apparatus is connected to the piezoelectric element via an impedance element for exciting the piezoelectric element with an A.C. signal. A feedback circuit is connected between the piezoelectric element and the drive apparatus. The feedback circuit picks out the components of a voltage on the piezoelectric element caused by a strain of the piezoelectric element and feeds this voltage back to control the drive apparatus. The inventive vibration control apparatus may be incorporated in a gyro to simplify the construction of the gyro.
    Type: Grant
    Filed: June 6, 1992
    Date of Patent: December 14, 1993
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5257109
    Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: October 26, 1993
    Assignee: Akai Electric Co., Ltd.
    Inventor: Tokuichi Minakawa
  • Patent number: 5256929
    Abstract: A vibrator support structure for a vibrator having a vibrating body comprises a support stand, a first damper material disposed on top of the support stand, and a first substrate disposed on top of the first damper material. In addition, the vibrator support structure includes a second damper material disposed on top of only a portion of the first substrate and a second substrate disposed on top of the second damper material. Two support filaments are also provided for supporting the vibrating body, one of which is mounted on the exposed portion of the first substrate, while the other of which is mounted on the second substrate.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: October 26, 1993
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5254898
    Abstract: A vibrator is disclosed having a vibrating body with a polygonal lateral cross-section. Two piezoelectric elements are disposed on nonparallel side surfaces of the vibrating body. A support structure is provided which supports the vibrating body at two support points of the vibrating body. The support points are located in a split plane which passes through the line of intersection of the two planes in which the two side surfaces lie and bisects the inner angle formed by these two planes. Furthermore, the support points are located on opposite sides of the vibrating body and each support point is located at or near a nodal point of the vibrator.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: October 19, 1993
    Assignee: Akai Electric Co., Ltd.
    Inventor: Kokichi Terajima
  • Patent number: 5249064
    Abstract: A magnetic recording/reproducing apparatus, which includes: a reproduced level detector for detecting the level of a reproduced signal and a memory for storing the reproduced level detected by the detector; and when recording a video signal, the signal is recorded and reproduced in advance, and this reproduced level is stored in the memory, so that an amount of emphasis of a detail emphasis circuit in a reproducing system and an amount of equalization of an FM equalizer in the recording system can be controlled in accordance with the stored reproduced level; while when reproducing the video signal, the level of a reproduced FM luminance signal is detected by the reproduced level detector, so that an amount of equalization of an FM equalizer, an amount of cancellation of a line noise canceler, and an amount of cancellation of a noise canceler in a reproducing system can respectively be controlled in accordance with the detected reproduced level; whereby the characteristic of a video tape can be controlled in a
    Type: Grant
    Filed: September 15, 1992
    Date of Patent: September 28, 1993
    Assignee: Akai Electric Co., Ltd.
    Inventor: Tokuichi Minakawa
  • Patent number: 5111346
    Abstract: A reproducing apparatus which is provided with: frequency converting means for performing frequency conversion of the FM regenerative signals respectively from the read heads, on the basis of frequency conversion signals each having a frequency different from the frequency of the carrier; voltage-controlled oscillators for generating the frequency conversion signals, respectively; phase comparators for comparing phases of two FM regenerative signals frequency-converted by the frequency converting means in the overlap period so as to produce a difference signal corresponding to the difference between the phases; switching circuits for feeding the difference signal generated by the phase comparators, into one of the voltage-controlled oscillators generating the frequency conversion signal for frequency conversion of succeedingly reproduced one of the FM regenerative signals in the overlap period; and loop filters for stabilizing a loop system constituted by the aforementioned parts; whereby the phases of two fr
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: May 5, 1992
    Assignee: Akai Electric Co., Ltd.
    Inventor: Hideo Matsuoka
  • Patent number: 4961017
    Abstract: A stator having a stator yoke, a first and second printed substrates, a plurality of drive coils and hall elements mounted on the first substrate, and a group of drive circuits mounted on the second substrate, wherein an end of the drive coil which is to be connected to the group of the drive circuits is directly connected to the second printed substrate.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: October 2, 1990
    Assignee: Akai Electric Co., Ltd.
    Inventors: Wataru Kakinoki, Noriaki Miyoshi, Koji Arai
  • Patent number: 4829463
    Abstract: A time-changing coefficient digital filter having a data RAM for storing input data, a purality of N data registers at the output of the data RAM forming a delay element, a coefficient RAM storing coefficient values, coefficient registers temporarily storing respective coefficients, and a multiplier for multiplying data read out of data registers and coefficient registers respectively. Data from the multiplier and inputs is accumulated in an adder. Coefficient registers and data registers are updated by data from the data RAM and coefficient RAM. The coefficient digital filter provides a sum of products sequentially read out of the coefficient and data registers. The digital filter is applied to produce a musical instrumet having improved tonal qualities.
    Type: Grant
    Filed: March 26, 1986
    Date of Patent: May 9, 1989
    Assignee: Akai Electric Co. Ltd.
    Inventors: Masahiro Kakishita, Hiroshi Katsumoto
  • Patent number: 4696306
    Abstract: A system and method for minimizing time-base fluctuations in playing back an electrocardiogram recorded on one track of a multi-track magnetic tape with reference clock signals recorded on another track. A sampling circuit samples the recorded electrocardiogram in response to sampling pulses produced in response to the recorded reference clock signals, and the sampled electrocardiogram is stored in a memory. The stored signal is then read in response to timing pulses produced by a generator. The phase difference between the sampling and timing pulses is detected and maintained constant.
    Type: Grant
    Filed: November 20, 1986
    Date of Patent: September 29, 1987
    Assignee: Akai Electric Co., Ltd.
    Inventor: Yoshihiko Shiozaki