Patents by Inventor Koichiro Nagata
Koichiro Nagata 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).
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Publication number: 20080169783Abstract: The present invention provides an induction motor controller which includes: a circuit for generating a d-axis current reference signal from a d-axis current command value and a periodically varying periodic signal; a d-axis current controller for controlling a d-axis motor current flowing through an induction motor to be controlled to match the d-axis current reference signal; parameter determining means for calculating and determining a motor parameter of the induction motor based on a deviation of the d-axis motor current from the d-axis current reference signal, and controlling a voltage applied to the induction motor using a compensation voltage calculated from the calculated and determined motor parameter, in which a control parameter for controlling the induction motor is set based on the calculated and determined motor parameter.Type: ApplicationFiled: August 23, 2007Publication date: July 17, 2008Inventors: KOUKI YAMAMOTO, Toshiaki Okuyama, Hiroyuki Tomita, Yoshitaka Iwaji, Koichiro Nagata
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Patent number: 7378984Abstract: On a display (100) end, maker codes and device codes are read from all STBs (110˜112) connected to the display (100) to create a connected-device table. When a user presses a button on a remote controller, the display receives a remote control code outputted from the remote controller, searches the connected-device table for a maker code and a device code that match the maker code and the device code included in the remote control code, controls a selector (105) so that a reception interface that is connected to an STB whose maker code and device code match those included in the remote control code is connected to a display section (102), thereby to display AV data transmitted from the STB on the display section (102).Type: GrantFiled: December 11, 2003Date of Patent: May 27, 2008Assignee: Matsushita Electric Industrial Co., LtdInventors: Hidekazu Suzuki, Yutaka Nio, Masazumi Yamada, Koichiro Nagata
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Publication number: 20080088291Abstract: An electric power converter apparatus having a function of converting a power source voltage into an AC voltage having an arbitrary frequency and maintaining an output voltage constant even on the power source variation, in which the electric power converter apparatus decreases the output voltage when the output voltage drops to equal to or less than a predetermined value, afterward, increases the output voltage in response to a predetermined rate of change when the power source voltage rises.Type: ApplicationFiled: August 22, 2007Publication date: April 17, 2008Inventors: Koichiro Nagata, Toshiaki Okuyama, Shigetoshi Okamatsu, Koichi Miyazaki
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Patent number: 7332888Abstract: A motor driving apparatus includes: a current instruction calculator, for calculating a current instruction value based on a deviation between a speed instruction value and an estimated speed value; a current controller, for controlling an output current based on the current instruction value; a frequency instruction calculator, for calculating a frequency instruction value based on an output voltage instruction value or an output voltage detection value, wherein, when an induction motor is to be activated, the current instruction value and the frequency instruction value are calculated directly using the speed instruction value, and an output current and an output frequency are controlled in accordance with the current instruction value and the frequency instruction value.Type: GrantFiled: February 23, 2006Date of Patent: February 19, 2008Assignee: Hitachi, Ltd.Inventors: Koichiro Nagata, Toshiaki Okuyama, Haruo Nemoto, Toshio Katayama
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Publication number: 20070210741Abstract: An object of the present invention is to provide a driver for an induction motor which performs an operation at an acceleration suitable for the magnitude of a load and is excellent in efficiency, without an acceleration failure. The driver for an induction motor includes a slip frequency estimate value arithmetic operation section 15 for arithmetically operating a slip frequency ?s? of an induction motor 12, and a maximum torque generation slip arithmetic operation section 16 for arithmetically operating a slip frequency ?smax at which a maximum torque is generated. When the slip frequency ?s? exceeds a predetermined value ?smaxTH(=0.96?smax, etc.) corresponding to the slip frequency ?smax at which the maximum torque is generated, a speed change rate arithmetic operation section 17 and a speed change rate correcting section 18 reduce a rate of increase in a speed command ?r*.Type: ApplicationFiled: January 25, 2007Publication date: September 13, 2007Inventors: Koichiro Nagata, Toshiaki Okuyama, Kouki Yamamoto, Hiroyuki Tomita
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Publication number: 20060192521Abstract: A motor driving apparatus includes: a current instruction calculator, for calculating a current instruction value based on a deviation between a speed instruction value and an estimated speed value; a current controller, for controlling an output current based on the current instruction value; a frequency instruction calculator, for calculating a frequency instruction value based on an output voltage instruction value or an output voltage detection value, wherein, when an induction motor is to be activated, the current instruction value and the frequency instruction value are calculated directly using the speed instruction value, and an output current and an output frequency are controlled in accordance with the current instruction value and the frequency instruction value.Type: ApplicationFiled: February 23, 2006Publication date: August 31, 2006Inventors: Koichiro Nagata, Toshiaki Okuyama, Haruo Nemoto, Toshio Katayama
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Publication number: 20040177537Abstract: When detecting that a display unit (3) of a vehicle-mounted display device (2) mounted to a vehicle ceiling (1) is placed in a use state 3a, a display unit opening and closing detector 101 sends out a use detection signal. A lighting control circuit (102) limits light emitted out of an indoor lighting device (6) and incident upon the screen of the display unit (3) according to the use detection signal from the display unit opening and closing detector (101).Type: ApplicationFiled: February 20, 2004Publication date: September 16, 2004Applicant: MITSUBISHI DENKI KABUSHIKI KAISHAInventor: Koichiro Nagata
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Publication number: 20040143847Abstract: On a display (100) end, maker codes and device codes are read from all STBs (110˜112) connected to the display (100) to create a connected-device table. When a user presses a button on a remote controller, the display receives a remote control code outputted from the remote controller, searches the connected-device table for a maker code and a device code that match the maker code and the device code included in the remote control code, controls a selector (105) so that a reception interface that is connected to an STB whose maker code and device code match those included in the remote control code is connected to a display section (102), thereby to display AV data transmitted from the STB on the display section (102).Type: ApplicationFiled: December 11, 2003Publication date: July 22, 2004Inventors: Hidekazu Suzuki, Yutaka Nio, Masazumi Yamada, Koichiro Nagata
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Patent number: 6646896Abstract: For use in a system in which a capacitor is connected between an AC machine and an inverter in order to improve the power factor, a controller for an AC machine capable of even when the overvoltage occurs due to the self-excitation between the AC machine and the capacitor, reactivating stably the inverter to continue the running. When the operation of the inverter is stopped and then the inverter is reactivated, the manipulation of starting the switching of the inverter is performed after a DC voltage of the inverter has been decreased to the operating voltage in the running, whereby the reactivation is performed stably without stopping the system.Type: GrantFiled: March 15, 2002Date of Patent: November 11, 2003Assignee: Hitachi, Ltd.Inventors: Yoshitoshi Akita, Toshiaki Okuyama, Koichiro Nagata, Shigetoshi Okamatsu
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Patent number: 6611125Abstract: An electric motor is rotated at a velocity &ohgr;1. After that, during &Dgr;t12 seconds, the 1st acceleration is executed at a rate (&ohgr;2−&ohgr;1)/&Dgr;t12. During this acceleration, the torque &tgr;m is calculated so as to execute the time integration. After the lapse of &Dgr;t12, the integrated result is stored. Next, the velocity is set to be &ohgr;3. After that, during &Dgr;t34 seconds, the 2nd acceleration is executed at a rate (&ohgr;4−&ohgr;3)/&Dgr;t34. At the 2nd acceleration, although the integration-starting and the integration-terminating velocities are each equal to those at the 1st acceleration, the acceleration rate is modified (&ohgr;3=&ohgr;1, &ohgr;4=&ohgr;2, &Dgr;t12≠&Dgr;t34). During this acceleration, the torque &tgr;m is calculated so as to execute the time integration, after the lapse of &Dgr;t34, storing the integrated result. The inertia J is calculated using the 1st and 2nd integrated results.Type: GrantFiled: February 26, 2001Date of Patent: August 26, 2003Assignee: Hitachi, Ltd.Inventors: Koichiro Nagata, Toshiaki Okuyama, Hiroshi Fujii, Shigetoshi Okamatsu
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Publication number: 20030043610Abstract: For use in a system in which a capacitor is connected between an AC machine and an inverter in order to improve the power factor, a controller for an AC machine capable of even when the overvoltage occurs due to the self-excitation between the AC machine and the capacitor, reactivating stably the inverter to continue the running. When the operation of the inverter is stopped and then the inverter is reactivated, the manipulation of starting the switching of the inverter is performed after a DC voltage of the inverter has been decreased to the operating voltage in the running, whereby the reactivation is performed stably without stopping the system.Type: ApplicationFiled: March 15, 2002Publication date: March 6, 2003Inventors: Yoshitoshi Akita, Toshiaki Okuyama, Koichiro Nagata, Shigetoshi Okamatsu
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Patent number: 6519408Abstract: In a display device used together with a playback apparatus such as an optical disk, a control is provided responding to a playback signal from an playback apparatus in order to prevent burn-out of CRT phosphor or deterioration of phosphor. A first controller controls the playback apparatus, and a second controller controls the display device, and those two controllers communicate with each other, thereby recognizing an operation status and a display status. Thus those two controllers control circuits and apparatus including a video control circuit which controls a contrast, whereby optimizing a display on a screen, and control status of an audio output, a power supply controller, and a playback apparatus controller.Type: GrantFiled: July 25, 1997Date of Patent: February 11, 2003Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Koichiro Nagata, Takaaki Hoshi, Masashi Imai
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Publication number: 20020097018Abstract: An electric motor is rotated at a velocity &ohgr;1. After that, during &Dgr;t12 seconds, the 1st acceleration is executed at a rate (&ohgr;2−&ohgr;1)/&Dgr;t12. During this acceleration, the torque &tgr;m is calculated so as to execute the time integration. After the lapse of &Dgr;t12, the integrated result is stored. Next, the velocity is set to be &ohgr;3. After that, during &Dgr;t34 seconds, the 2nd acceleration is executed at a rate (&ohgr;4−&ohgr;3)/&Dgr;t34. At the 2nd acceleration, although the integration-starting and the integration-terminating velocities are each equal to those at the 1st acceleration, the acceleration rate is modified (&ohgr;3=&ohgr;1, &ohgr;4=&ohgr;2, &Dgr;t12≠&Dgr;t34). During this acceleration, the torque &tgr;m is calculated so as to execute the time integration, after the lapse of &Dgr;t34, storing the integrated result. The inertia J is calculated using the 1st and 2nd integrated results.Type: ApplicationFiled: February 26, 2001Publication date: July 25, 2002Inventors: Koichiro Nagata, Toshiaki Okuyama, Hiroshi Fujii, Shigetoshi Okamatsu
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Patent number: 6392695Abstract: An image display device having (a) a DVD or a CD, (b) a television receiver, (c) a display for displaying an image from the DVD and the television receiver, (d) a screen burn-in preventer, and (e) a deterioration protector for protecting the display device from deterioration. The screen burn-in preventer discontinues reproduction from the DVD when an image reproduced of the DVD becomes stationary, and the stationary state continues for the predetermined time period. The deterioration protector discontinues reproduction from the DVD at a second predetermined time after the television receiver is turned on while an image reproduced from the DVD is displayed by the display.Type: GrantFiled: April 17, 1998Date of Patent: May 21, 2002Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Toru Watamoto, Koichiro Nagata
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Publication number: 20010010749Abstract: In a display device used together with a playback apparatus such as an optical disk, a control is provided responding to a playback signal from an playback apparatus in order to prevent burn-out of CRT phosphor or deterioration of phosphor. A first controller controls the playback apparatus, and a second controller controls the display device, and those two controllers communicate with each other, thereby recognizing an operation status and a display status. Thus those two controllers control circuits and apparatus including a video control circuit which controls a contrast, whereby optimizing a display on a screen, and control status of an audio output, a power supply controller, and a playback apparatus controller.Type: ApplicationFiled: July 25, 1997Publication date: August 2, 2001Inventors: KOICHIRO NAGATA, TAKAAKI HOSHI, MASASHI IMAI
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Patent number: 6028943Abstract: Class D amplifiers are difficult to incorporate into audio amplifier systems because of the interference created by the amplifier and/or the surrounding circuits. The modulation frequencies f1 and f2 of two class D amplifiers in an audio amplifier system are adjusted so that the frequency f1-f2 of interference between the modulation frequencies is outside the reproducible frequency band B1 of speakers converting the class D amplifier output to audible sound. As a result, interference that may result from simultaneous use of two class D amplifiers for similar purposes is inaudible and not perceived as noise.Type: GrantFiled: April 27, 1999Date of Patent: February 22, 2000Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Koichiro Nagata
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Patent number: 6008842Abstract: A protective circuit and a signal processor for a three-CRT projection TV for preventing CRT burnout, deterioration of luminous characteristics, and damage to lenses by heat. Each CRT beam current detection circuit detects the beam current of each CRT. A state of the video image is predicted based on the detected beam current values and their duration. A microcomputer determines a control voltage for controlling the contrast based on the state of the video image, detected values, and their duration. The contrast is thus controlled by a control signal output to a video control circuit which controls the beam current.Type: GrantFiled: April 18, 1997Date of Patent: December 28, 1999Assignee: Matsushita Electric Industrial Co., Ltd.Inventor: Koichiro Nagata
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Patent number: 5017364Abstract: Herein is disclosed a paste-like dentifrice composition containing, as the foaming agent, from 0.1 to 5.0% by weight of highly pure N-long-chain acylglutamate which contains not more than 1.0% by weight of higher fatty acid(s), either in the free form or in the salt form.Type: GrantFiled: October 17, 1989Date of Patent: May 21, 1991Assignee: Ajinomoto Co., Inc.Inventors: Hiromi Mitsutake, Hideomi Saitoh, Koichiro Nagata