Patents by Inventor Gentaro Kurokawa
Gentaro Kurokawa 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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Patent number: 9225182Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.Type: GrantFiled: January 23, 2013Date of Patent: December 29, 2015Assignee: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro Kurokawa, Daisuke Suzuki, Junji Takeshita
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Patent number: 9219368Abstract: A charge controller includes a charge control circuit which controls a charging transistor; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to block discharge current and when the secondary battery is overcharged, turns off the second control switch element to prevent the charge current from flowing. The charge control circuit includes a function of control for applying constant charge current through the charging transistor until the voltage of the secondary battery reaches a predetermined value and switching to control for applying charge current at a constant voltage after the voltage of the secondary battery reaches the predetermined value, and a terminal voltage on the positive electrode side and a terminal voltage on the negative electrode side of the secondary battery are supplied as monitoring voltage to the charge control circuit.Type: GrantFiled: January 23, 2013Date of Patent: December 22, 2015Assignee: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro Kurokawa, Daisuke Suzuki, Junji Takeshita
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Patent number: 9197084Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.Type: GrantFiled: January 23, 2013Date of Patent: November 24, 2015Assignee: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro Kurokawa, Daisuke Suzuki, Junji Takeshita
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Patent number: 9166432Abstract: A charge circuit includes a current limiting circuit configured to limit a current input from an input terminal; a first transistor connected between an output terminal of the current limiting circuit and a secondary battery; a charge control circuit configured to turn the first transistor on and off to start and stop supply of a charge current to the secondary battery; a second transistor configured to output a current proportional to the charge current flowing through the first transistor; and a charge timer configured to generate clock pulses according to the current output from the second transistor. The charge control circuit is configured to turn off the first transistor to stop the supply of the charge current to the secondary battery when the number of the clock pulses reaches a predetermined number.Type: GrantFiled: February 1, 2013Date of Patent: October 20, 2015Assignee: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro Kurokawa, Daisuke Suzuki, Toshiki Sakamoto
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Patent number: 8558516Abstract: A charge-controlling semiconductor integrated circuit includes a current- controlling MOS transistor which is connected between a voltage input terminal and an output terminal and controls flowing current, a substratum voltage switching circuit connected between the voltage input/output terminal and a substratum to which an input/output voltage is applied, and a voltage comparison circuit to compare the input/output voltage. The charge-controlling semiconductor integrated circuit controls the substratum voltage switching circuit based on an output of the voltage comparison circuit, and the voltage comparison circuit includes an intentional offset in a first potential direction. A level shift circuit to shift the output voltage to a potential direction opposite to the first potential direction is provided in a preceding stage of a first input terminal of the voltage comparison circuit, and the input voltage is input to a second input terminal of the voltage comparison circuit.Type: GrantFiled: May 18, 2009Date of Patent: October 15, 2013Assignee: Mitsumi Electric Co., Ltd.Inventors: Yoshihiro Takahashi, Daisuke Suzuki, Yoshihiro Motoichi, Gentaro Kurokawa
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Publication number: 20130207597Abstract: A charge circuit includes a current limiting circuit configured to limit a current input from an input terminal; a first transistor connected between an output terminal of the current limiting circuit and a secondary battery; a charge control circuit configured to turn the first transistor on and off to start and stop supply of a charge current to the secondary battery; a second transistor configured to output a current proportional to the charge current flowing through the first transistor; and a charge timer configured to generate clock pulses according to the current output from the second transistor. The charge control circuit is configured to turn off the first transistor to stop the supply of the charge current to the secondary battery when the number of the clock pulses reaches a predetermined number.Type: ApplicationFiled: February 1, 2013Publication date: August 15, 2013Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro KUROKAWA, Daisuke Suzuki, Toshiki Sakamoto
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Publication number: 20130200847Abstract: A charge controller includes a charge control circuit that, when detecting that a charging power supply is connected, controls the charging transistor to apply the charge current; a first and second control switch element connected in series between one terminal of a secondary battery and an external terminal; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to stop discharge current and when deeply discharged, turns off the second control switch element. The protection circuit sends a charge inhibit signal to the charge control circuit when the secondary battery is deeply discharged, and while receiving the charge inhibit signal, the charge control circuit keeps the charging transistor off to prevent the charge current from flowing even if detecting that the charging power supply is connected.Type: ApplicationFiled: January 23, 2013Publication date: August 8, 2013Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro KUROKAWA, Daisuke SUZUKI, Junji TAKESHITA
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Publication number: 20130193924Abstract: A charge controller includes a charge control circuit which controls a charging transistor; and a protection circuit that, when the secondary battery is over-discharged, turns off the first control switch element to block discharge current and when the secondary battery is overcharged, turns off the second control switch element to prevent the charge current from flowing. The charge control circuit includes a function of control for applying constant charge current through the charging transistor until the voltage of the secondary battery reaches a predetermined value and switching to control for applying charge current at a constant voltage after the voltage of the secondary battery reaches the predetermined value, and a terminal voltage on the positive electrode side and a terminal voltage on the negative electrode side of the secondary battery are supplied as monitoring voltage to the charge control circuit.Type: ApplicationFiled: January 23, 2013Publication date: August 1, 2013Applicant: MITSUMI ELECTRIC CO., LTD.Inventors: Gentaro KUROKAWA, Daisuke SUZUKI, Junji TAKESHITA
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Patent number: 8179098Abstract: Disclosed is a charge controlling semiconductor integrated circuit including: an electric current controlling transistor connected between a voltage input terminal and an output terminal to control an electric current which flows from the voltage input terminal to the output terminal; a power source monitoring circuit to detect status of input voltage of the voltage input terminal; and a transistor element connected between the voltage input terminal and a ground potential point, wherein a bypass capacitor is connected to the voltage input terminal; and the transistor element is turned on and the bypass capacitor discharges when the power source monitoring circuit detects the input voltage of the voltage input terminal is cut off.Type: GrantFiled: September 1, 2009Date of Patent: May 15, 2012Assignee: Mitsumi Electric Co., Ltd.Inventors: Gentaro Kurokawa, Yoshihiro Takahashi
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Patent number: 8035355Abstract: Disclosed is a charge-controlling semiconductor integrated circuit including: a current-controlling MOS transistor; a current detection circuit including a 1/N size current-detecting MOS transistor; and a gate voltage control circuit, wherein the current detection circuit includes an operational amplifier circuit, a bias condition of the current-detecting MOS transistor becomes same as the current-controlling MOS transistor based on an operational amplifier circuit output, voltage drops in lines from drain electrode to a corresponding input point of the operational amplifier circuit become the same by a parasitic resistance, and when the output of the operational amplifier circuit is applied to a control terminal of the bias condition controlling transistor, the drain voltages become the same potential, and the line from the drain electrode of the current-detecting MOS transistor to the input point is formed to be redundantly arranged inside the chip so that a parasitic resistance becomes a predetermined valuType: GrantFiled: June 4, 2009Date of Patent: October 11, 2011Assignee: Mitsumi Electric Co., Ltd.Inventors: Yoshihiro Motoichi, Daisuke Suzuki, Yoshihiro Takahashi, Gentaro Kurokawa
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Publication number: 20100060244Abstract: Disclosed is a charge controlling semiconductor integrated circuit including: an electric current controlling transistor connected between a voltage input terminal and an output terminal to control an electric current which flows from the voltage input terminal to the output terminal; a power source monitoring circuit to detect status of input voltage of the voltage input terminal; and a transistor element connected between the voltage input terminal and a ground potential point, wherein a bypass capacitor is connected to the voltage input terminal; and the transistor element is turned on and the bypass capacitor discharges when the power source monitoring circuit detects the input voltage of the voltage input terminal is cut off.Type: ApplicationFiled: September 1, 2009Publication date: March 11, 2010Applicant: Mitsumi Electric Co., Ltd.Inventors: Gentaro KUROKAWA, Yoshihiro Takahashi
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Patent number: 7656218Abstract: A signal output circuit is disclosed that supplies a signal from a first circuit that is driven based on a first reference voltage to a second circuit that is driven based on a second reference voltage. The signal output circuit includes a first control circuit that draws a current to the first reference voltage according to an output signal from the first circuit and supplies a signal to the second circuit according to the drawn current, and a second control circuit that draws a current from the second circuit to the second reference voltage.Type: GrantFiled: February 7, 2007Date of Patent: February 2, 2010Assignee: Mitsumi Electric Co., Ltd.Inventors: Gentaro Kurokawa, Nagayoshi Dobashi
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Publication number: 20090302805Abstract: Disclosed is a charge-controlling semiconductor integrated circuit including: a current-controlling MOS transistor; a current detection circuit including a 1/N size current-detecting MOS transistor; and a gate voltage control circuit, wherein the current detection circuit includes an operational amplifier circuit, a bias condition of the current-detecting MOS transistor becomes same as the current-controlling MOS transistor based on an operational amplifier circuit output, voltage drops in lines from drain electrode to a corresponding input point of the operational amplifier circuit become the same by a parasitic resistance, and when the output of the operational amplifier circuit is applied to a control terminal of the bias condition controlling transistor, the drain voltages become the same potential, and the line from the drain electrode of the current-detecting MOS transistor to the input point is formed to be redundantly arranged inside the chip so that a parasitic resistance becomes a predetermined valuType: ApplicationFiled: June 4, 2009Publication date: December 10, 2009Applicant: Mitsumi Electric Co. Ltd.Inventors: Yoshihiro MOTOICHI, Daisuke Suzuki, Yoshihiro Takahashi, Gentaro Kurokawa
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Publication number: 20090289605Abstract: Disclosed a charge-controlling semiconductor integrated circuit comprising: a current-controlling MOS transistor connected between a voltage input terminal and an output terminal and controls flowing current; a substratum voltage switching circuit connected between the voltage input/output terminal and a substratum to which an input/output voltage is applied; and a voltage comparison circuit to compare the input/output voltage, wherein the charge-controlling semiconductor integrated circuit controls the substratum voltage switching circuit based on an output of the voltage comparison circuit, the voltage comparison circuit includes an intentional offset in a first potential direction, and in a preceding stage of a first input terminal of the voltage comparison circuit, a level shift circuit to shift the output voltage to an opposite potential direction is provided, and to a second input terminal of the voltage comparison circuit, the input voltage is input.Type: ApplicationFiled: May 18, 2009Publication date: November 26, 2009Applicant: Mitsumi Electric Co. Ltd.Inventors: Yoshihiro TAKAHASHI, Daisuke Suzuki, Yoshihiro Motoichi, Gentaro Kurokawa
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Publication number: 20070188217Abstract: A signal output circuit is disclosed that supplies a signal from a first circuit that is driven based on a first reference voltage to a second circuit that is driven based on a second reference voltage. The signal output circuit includes a first control circuit that draws a current to the first reference voltage according to an output signal from the first circuit and supplies a signal to the second circuit according to the drawn current, and a second control circuit that draws a current from the second circuit to the second reference voltage.Type: ApplicationFiled: February 7, 2007Publication date: August 16, 2007Inventors: Gentaro Kurokawa, Nagayoshi Dobashi