Patents by Inventor Nagayoshi Dobashi
Nagayoshi Dobashi 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: 8390742Abstract: In a semiconductor integrated circuit arranged to perform sag compensation for a video signal, an operational amplifier includes a non-inverted input terminal, an inverted input terminal, and an output terminal, in which a video signal is input to the non-inverted input terminal. A first resistor includes a first end connected to the inverted input terminal and a second end being grounded. The output terminal is connected to a first external terminal and the inverted input terminal is connected to a second external terminal. A second resistor includes a first end connected to the output terminal and a second end connected to the inverted input terminal. A first capacitor is disposed between the first external terminal and the second external terminal and connected in parallel to the second resistor, and the second resistor has a resistance value determined based on a capacitance value of the first capacitor.Type: GrantFiled: January 13, 2010Date of Patent: March 5, 2013Assignee: Mitsumi Electric Co., Ltd.Inventors: Shuhei Abe, Nagayoshi Dobashi, Yoshiaki Hirano
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Patent number: 8184207Abstract: An image signal input circuit includes an input terminal configured to receive an image signal, a clamp circuit configured to hold a sink chip voltage contained in the image signal to be a constant value, a level shift circuit that includes a first emitter follower having a first transistor and a first current source, and a second emitter follower having a second transistor and a second current source, a base of the second transistor being connected to an emitter of the first transistor, and that is configured to shift a level of the sink chip voltage which is held constant, and an electric current source configured to attract a base current of the first transistor.Type: GrantFiled: April 14, 2010Date of Patent: May 22, 2012Assignee: Mitsumi Electric Co., Ltd.Inventors: Shigeki Mabuchi, Atsushi Watanabe, Makoto Seino, Nagayoshi Dobashi
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Patent number: 7872534Abstract: An image signal amplifying circuit comprises: an amplifier circuit for amplifying an image signal; an output capacitor and a resistance, both being serially connected between an output node of the amplifier circuit and an output terminal; and a second-order high pass filter having a value of Q larger than one, the second-order high pass filter being provided at a preceding stage of the amplifier circuit, wherein distortion to correct a sag arising in a high pass filter on an output side, the high pass filter including the output capacitor and the resistance, is caused in the input image signal by a characteristic of the second-order high pass filter.Type: GrantFiled: October 29, 2008Date of Patent: January 18, 2011Assignee: Mitsumi Electric Co., Ltd.Inventor: Nagayoshi Dobashi
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Publication number: 20100271104Abstract: An image signal input circuit includes an input terminal configured to receive an image signal, a clamp circuit configured to hold a sink chip voltage contained in the image signal to be a constant value, a level shift circuit that includes a first emitter follower having a first transistor and a first current source, and a second emitter follower having a second transistor and a second current source, a base of the second transistor being connected to an emitter of the first transistor, and that is configured to shift a level of the sink chip voltage which is held constant, and an electric current source configured to attract a base current of the first transistor.Type: ApplicationFiled: April 14, 2010Publication date: October 28, 2010Inventors: SHIGEKI MABUCHI, Atsushi Watanabe, Makoto Seino, Nagayoshi Dobashi
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Publication number: 20100182512Abstract: In a semiconductor integrated circuit arranged to perform sag compensation for a video signal, an operational amplifier includes a non-inverted input terminal, an inverted input terminal, and an output terminal, in which a video signal is input to the non-inverted input terminal. A first resistor includes a first end connected to the inverted input terminal and a second end being grounded. The output terminal is connected to a first external terminal and the inverted input terminal is connected to a second external terminal. A second resistor includes a first end connected to the output terminal and a second end connected to the inverted input terminal. A first capacitor is disposed between the first external terminal and the second external terminal and connected in parallel to the second resistor, and the second resistor has a resistance value determined based on a capacitance value of the first capacitor.Type: ApplicationFiled: January 13, 2010Publication date: July 22, 2010Inventors: Shuhei ABE, Nagayoshi DOBASHI, Yoshiaki HIRANO
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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: 20090115532Abstract: An image signal amplifying circuit comprises: an amplifier circuit for amplifying an image signal; an output capacitor and a resistance, both being serially connected between an output node of the amplifier circuit and an output terminal; and a second-order high pass filter having a value of Q larger than one, the second-order high pass filter being provided at a preceding stage of the amplifier circuit, wherein distortion to correct a sag arising in a high pass filter on an output side, the high pass filter including the output capacitor and the resistance, is caused in the input image signal by a characteristic of the second-order high pass filter.Type: ApplicationFiled: October 29, 2008Publication date: May 7, 2009Applicant: Mitsumi Electric Co. Ltd.Inventor: Nagayoshi Dobashi
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Patent number: 7501893Abstract: A variable gain amplifier circuit capable of eliminating circuit elements and the area for circuits when formed into an integrated circuit is disclosed. The circuit includes plural differential circuits, one of the input terminals of each of the differential circuits being connected in common to a signal input terminal, any one of the differential circuits being selected to operate; an output circuit having an input terminal connected in common to each output terminal of the differential circuits, the output circuit inputting an output signal of any of differential circuits and outputting an output signal from the signal output terminal; and plural resistors connected in series between the signal output terminal and a reference voltage terminal, in which each of junctions between the resistors is connected to one of the other input terminals of the differential circuits.Type: GrantFiled: October 24, 2007Date of Patent: March 10, 2009Assignee: Mitsumi Electric Co., Ltd.Inventors: Nagayoshi Dobashi, Shigeki Mabuchi
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Publication number: 20080129384Abstract: A variable-gain amplifier circuit capable of eliminating circuit elements and the area for circuits when formed into an integrated circuit is disclosed. The circuit includes plural differential circuits, one of the input terminals of each of the differential circuits being connected in common to a signal input terminal, any one of the differential circuits being selected to operate; an output circuit having an input terminal connected in common to each output terminal of the differential circuits, the output circuit inputting an output signal of any of differential circuits and outputting an output signal from the signal output terminal; and plural resistors connected in series between the signal output terminal and a reference voltage terminal, in which each of junctions between the resistors is connected to one of the other input terminals of the differential circuits.Type: ApplicationFiled: October 24, 2007Publication date: June 5, 2008Inventors: Nagayoshi DOBASHI, Shigeki MABUCHI
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Patent number: 7345546Abstract: A disclosed amplifier circuit is capable of changing a gain to amplify an input signal according to a control signal. The amplifier circuit comprises a differential amplifier circuit adapted to receive and amplify the input signal to output the amplified input signal as an output signal, a first resistance and one or more second resistances connected to the differential amplifier circuit and adapted to set the gain, and one or more gain control circuits adapted to change the gain by controlling one or more electrical couplings of the one or more second resistances according to the control signal.Type: GrantFiled: February 25, 2005Date of Patent: March 18, 2008Assignee: Mitsumi Electric Co., Ltd.Inventors: Akihiro Terada, Nagayoshi Dobashi
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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
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Publication number: 20060066402Abstract: A disclosed amplifier circuit is capable of changing a gain to amplify an input signal according to a control signal. The amplifier circuit comprises a differential amplifier circuit adapted to receive and amplify the input signal to output the amplified input signal as an output signal, a first resistance and one or more second resistances connected to the differential amplifier circuit and adapted to set the gain, and one or more gain control circuits adapted to change the gain by controlling one or more electrical couplings of the one or more second resistances according to the control signal.Type: ApplicationFiled: February 25, 2005Publication date: March 30, 2006Inventors: Akihiro Terada, Nagayoshi Dobashi
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Patent number: 6882183Abstract: In a multi-level output circuit, an amplifier circuit amplifies a constant input voltage and outputs the amplified constant input voltage. The multi-level output circuit is capable of selectively outputting signals of different levels by switching the gain of the amplifier circuit by a switch.Type: GrantFiled: June 26, 2003Date of Patent: April 19, 2005Assignee: Mitsumi Electric Co., Ltd.Inventor: Nagayoshi Dobashi
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Publication number: 20040056714Abstract: In a multi-level output circuit, an amplifier circuit amplifies a constant input voltage and outputs the amplified constant input voltage. The multi-level output circuit is capable of selectively outputting signals of different levels by switching the gain of the amplifier circuit by a switch.Type: ApplicationFiled: June 26, 2003Publication date: March 25, 2004Applicant: MITSUMI ELECTRIC CO., LTD.Inventor: Nagayoshi Dobashi