Patents by Inventor Hideto Okahara
Hideto Okahara 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: 7705580Abstract: In a system, an output voltage of a power generator is input to a filter circuit. The filter circuit includes a first capacitor having opposing first and second electrodes, a second capacitor having opposing third and fourth electrodes, a first switch electrically connected to be series with the third electrode of the second capacitor, and a second switch electrically connected to be series with the fourth electrode of the second capacitor. A series circuit of series-connected first switch, the second capacitor, and the second switch is electrically connected with the first capacitor in parallel thereto. A control circuit is electrically connected to the first and second switches of the filter circuit. The control unit is configured to control the first and second switches to be substantially simultaneously on and off to thereby cause the filter circuit to filter the frequency components from the output voltage.Type: GrantFiled: August 3, 2007Date of Patent: April 27, 2010Assignee: Denso CorporationInventors: Hideto Okahara, Tadatoshi Asada
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Patent number: 7505240Abstract: An overcurrent protecting device for protecting a semiconductor element from an overcurrent includes: the semiconductor element; a shunt resistor for detecting the overcurrent when the electric current in the semiconductor element exceeds a threshold value; a reference resistor for setting the threshold value; a constant electric current circuit for supplying a constant electric current to the reference resistor; and a comparator for comparing a terminal voltage of the shunt resistor and a terminal voltage of the reference resistor. The shunt resistor is made of a same kind of resistor as the reference resistor.Type: GrantFiled: November 21, 2006Date of Patent: March 17, 2009Assignee: DENSO CORPORATIONInventors: Tadatoshi Asada, Hideto Okahara, Susumu Ueda
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Publication number: 20080030184Abstract: In a system, an output voltage of a power generator is input to a filter circuit. The filter circuit includes a first capacitor having opposing first and second electrodes, a second capacitor having opposing third and fourth electrodes, a first switch electrically connected to be series with the third electrode of the second capacitor, and a second switch electrically connected to be series with the fourth electrode of the second capacitor. A series circuit of series-connected first switch, the second capacitor, and the second switch is electrically connected with the first capacitor in parallel thereto. A control circuit is electrically connected to the first and second switches of the filter circuit. The control unit is configured to control the first and second switches to be substantially simultaneously on and off to thereby cause the filter circuit to filter the frequency components from the output voltage.Type: ApplicationFiled: August 3, 2007Publication date: February 7, 2008Applicant: DENSO CORPORATIONInventors: Hideto Okahara, Tadatoshi Asada
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Patent number: 7304455Abstract: The power generation controller includes a control command receiving section receiving a control command transmitted from an external control unit for controlling an internal combustion engine, a control command holding section holding the control command received by the control command receiving section, and an excitation current control section controlling an excitation current of a generator driven by the internal combustion engine on the basis of the control command held by the control command holding section. The excitation current control section is configured to control the excitation current on the basis of a control command transmitted from the external control unit when the internal combustion engine is in a stopped sate.Type: GrantFiled: March 20, 2006Date of Patent: December 4, 2007Assignee: Denso CorporationInventors: Hideto Okahara, Tadatoshi Asada
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Publication number: 20070146952Abstract: An overcurrent protecting device for protecting a semiconductor element from an overcurrent includes: the semiconductor element; a shunt resistor for detecting the overcurrent when the electric current in the semiconductor element exceeds a threshold value; a reference resistor for setting the threshold value; a constant electric current circuit for supplying a constant electric current to the reference resistor; and a comparator for comparing a terminal voltage of the shunt resistor and a terminal voltage of the reference resistor. The shunt resistor is made of a same kind of resistor as the reference resistor.Type: ApplicationFiled: November 21, 2006Publication date: June 28, 2007Applicant: DENSO CORPORATIONInventors: Tadatoshi Asada, Hideto Okahara, Susumu Ueda
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Patent number: 7180272Abstract: An apparatus is provided for detecting a malfunction in an on-vehicle charging system provided with a generator driven by an engine and a battery connected with the generator via a charging line. The apparatus comprises a first control unit controlling a generated condition of the generator and including a first voltage detector detecting a voltage generated by the generator and a second control unit including a second voltage detector detecting a voltage across the battery. The apparatus further comprises a communication device communicating, in the form of digital signals, via a communication line between the first and second control units, information about both the generated voltage and the battery voltage and a malfunction determination unit determining whether or not a malfunction occurs in the charging system on the basis of the communicated information.Type: GrantFiled: April 14, 2005Date of Patent: February 20, 2007Assignee: Denso CorporationInventors: Hideto Okahara, Tadatoshi Asada, Fuyuki Maehara
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Publication number: 20060214644Abstract: The power generation controller includes a control command receiving section receiving a control command transmitted from an external control unit for controlling an internal combustion engine, a control command holding section holding the control command received by the control command receiving section, and an excitation current control section controlling an excitation current of a generator driven by the internal combustion engine on the basis of the control command held by the control command holding section. The excitation current control section is configured to control the excitation current on the basis of a control command transmitted from the external control unit when the internal combustion engine is in a stopped sate.Type: ApplicationFiled: March 20, 2006Publication date: September 28, 2006Applicant: DENSO CORPORATIONInventors: Hideto Okahara, Tadatoshi Asada
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Publication number: 20050242784Abstract: An apparatus is provided for detecting a malfunction in an on-vehicle charging system provided with a generator driven by an engine and a battery connected with the generator via a charging line. The apparatus comprises a first control unit controlling a generated condition of the generator and including a first voltage detector detecting a voltage generated by the generator and a second control unit including a second voltage detector detecting a voltage across the battery. The apparatus further comprises a communication device communicating, in the form of digital signals, via a communication line between the first and second control units, information about both the generated voltage and the battery voltage and a malfunction determination unit determining whether or not a malfunction occurs in the charging system on the basis of the communicated information.Type: ApplicationFiled: April 14, 2005Publication date: November 3, 2005Applicant: Denso CorporationInventors: Hideto Okahara, Tadatoshi Asada, Fuyuki Maehara
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Patent number: 6707275Abstract: A voltage regulator of an automotive generator has a MOS transistor, flywheel diode, voltage detection circuit, and booster circuit. When a battery terminal voltage is below a voltage adjustment setting, current is supplied by a current supply circuit separate from a charge pump circuit to raise a gate voltage of the MOS transistor until the source voltage of the MOS transistor becomes greater than the reverse bias voltage of the flywheel diode, and the charge pump circuit output is applied to the MOS transistor after this specified value is reached. The charge pump circuit has an even number of capacitor stages.Type: GrantFiled: August 29, 2001Date of Patent: March 16, 2004Assignee: Denso CorporationInventors: Hideto Okahara, Fuyuki Maehara, Toshinori Maruyama
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Publication number: 20020027426Abstract: A voltage regulator of an automotive generator has a MOS transistor, flywheel diode, voltage detection circuit, and booster circuit. When a battery terminal voltage is below a voltage adjustment setting, current is supplied by a current supply circuit separate from a charge pump circuit to raise a gate voltage of the MOS transistor until the source voltage of the MOS transistor becomes greater than the reverse bias voltage of the flywheel diode, and the charge pump circuit output is applied to the MOS transistor after this specified value is reached. The charge pump circuit has an even number of capacitor stages.Type: ApplicationFiled: August 29, 2001Publication date: March 7, 2002Applicant: DENSO CORPORATIONInventors: Hideto Okahara, Fuyuki Maehara, Toshinori Maruyama