Patents by Inventor Yusuke Minakuchi

Yusuke Minakuchi 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).

  • Patent number: 7948223
    Abstract: A constant voltage circuit that is capable of realizing high speed response with respect to an abrupt change in an input voltage or a load current is disclosed. The constant voltage circuit includes a first error amplifier with a high direct current gain and a second error amplifier with high speed responsiveness with respect to a change in an output voltage. The constant voltage circuit uses the first and second error amplifiers to conduct operation control of an output voltage control transistor in response to a change in the output voltage.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: May 24, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihisa Nagata, Kohji Yoshii, Yusuke Minakuchi
  • Patent number: 7772817
    Abstract: A constant voltage circuit which is capable of quickly responding to a sudden change of an output voltage includes an output transistor, and first and second error amplifiers. The output transistor outputs a power with an output voltage and an output current to a load. The first error amplifier is configured to increase a response speed with respect to changes of the output voltage in accordance with an increase of the output current so as to control operations of the output transistor. The second error amplifier has a response speed faster than the first error amplifier with respect to changes of the output voltage, and is configured to decrease a gain thereof in response to a drain current of the output transistor.
    Type: Grant
    Filed: August 11, 2008
    Date of Patent: August 10, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiki Takagi, Yusuke Minakuchi
  • Patent number: 7538537
    Abstract: A constant-voltage circuit in which a response speed for a sudden change of an input voltage or a sudden change of a load current can be fast are disclosed. In normal operating conditions, a first control circuit (error amplifier circuit) having an excellent direct-current characteristic controls operations of an output voltage control transistor and an output voltage is made a constant voltage. When the output voltage is suddenly decreased, before the first control circuit controls the operations of the output voltage control transistor by responding to the sudden decrease of the output voltage, an amplifier circuit having a high-speed response characteristic amplifies the change of the output voltage, and when the amplified voltage obtained by the amplification is suddenly decreased, a second control circuit controls the operations of the output voltage control transistor for a predetermined period. With this, the output voltage can be a constant voltage.
    Type: Grant
    Filed: October 23, 2006
    Date of Patent: May 26, 2009
    Assignees: Ricoh Company, Ltd., Analog Research Limited
    Inventors: Yusuke Minakuchi, Yoshiki Takagi
  • Publication number: 20090015222
    Abstract: A constant voltage circuit which is capable of quickly responding to a sudden change of an output voltage includes an output transistor, and first and second error amplifiers. The output transistor outputs a power with an output voltage and an output current to a load. The first error amplifier is configured to increase a response speed with respect to changes of the output voltage in accordance with an increase of the output current so as to control operations of the output transistor. The second error amplifier has a response speed faster than the first error amplifier with respect to changes of the output voltage, and is configured to decrease a gain thereof in response to a drain current of the output transistor.
    Type: Application
    Filed: August 11, 2008
    Publication date: January 15, 2009
    Inventors: Yoshiki Takagi, Yusuke Minakuchi
  • Publication number: 20080238385
    Abstract: A constant voltage circuit that is capable of realizing high speed response with respect to an abrupt change in an input voltage or a load current is disclosed. The constant voltage circuit includes a first error amplifier with a high direct current gain and a second error amplifier with high speed responsiveness with respect to a change in an output voltage. The constant voltage circuit uses the first and second error amplifiers to conduct operation control of an output voltage control transistor in response to a change in the output voltage.
    Type: Application
    Filed: March 27, 2008
    Publication date: October 2, 2008
    Inventors: Toshihisa Nagata, Kohji Yoshii, Yusuke Minakuchi
  • Patent number: 7429852
    Abstract: A constant voltage circuit which is capable of quickly responding to a sudden change of an output voltage includes an output transistor, and first and second error amplifiers. The output transistor outputs a power with an output voltage and an output current to a load. The first error amplifier is configured to increase a response speed with respect to changes of the output voltage in accordance with an increase of the output current so as to control operations of the output transistor. The second error amplifier has a response speed faster than the first error amplifier with respect to changes of the output voltage, and is configured to decrease a gain thereof in response to a drain current of the output transistor.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: September 30, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshiki Takagi, Yusuke Minakuchi
  • Patent number: 7368896
    Abstract: A constant voltage circuit that is capable of realizing high speed response with respect to an abrupt change in an input voltage or a load current is disclosed. The constant voltage circuit includes a first error amplifier with a high direct current gain and a second error amplifier with high speed responsiveness with respect to a change in an output voltage. The constant voltage circuit uses the first and second error amplifiers to conduct operation control of an output voltage control transistor in response to a change in the output voltage.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: May 6, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Toshihisa Nagata, Kohji Yoshii, Yusuke Minakuchi
  • Publication number: 20070108958
    Abstract: A constant-voltage circuit in which a response speed for a sudden change of an input voltage or a sudden change of a load current can be fast are disclosed. In normal operating conditions, a first control circuit (error amplifier circuit) having an excellent direct-current characteristic controls operations of an output voltage control transistor and an output voltage is made a constant voltage. When the output voltage is suddenly decreased, before the first control circuit controls the operations of the output voltage control transistor by responding to the sudden decrease of the output voltage, an amplifier circuit having a high-speed response characteristic amplifies the change of the output voltage, and when the amplified voltage obtained by the amplification is suddenly decreased, a second control circuit controls the operations of the output voltage control transistor for a predetermined period. With this, the output voltage can be a constant voltage.
    Type: Application
    Filed: October 23, 2006
    Publication date: May 17, 2007
    Inventors: Yusuke Minakuchi, Yoshiki Takagi
  • Publication number: 20060232327
    Abstract: A constant voltage circuit which is capable of quickly responding to a sudden change of an output voltage includes an output transistor, and first and second error amplifiers. The output transistor outputs a power with an output voltage and an output current to a load. The first error amplifier is configured to increase a response speed with respect to changes of the output voltage in accordance with an increase of the output current so as to control operations of the output transistor. The second error amplifier has a response speed faster than the first error amplifier with respect to changes of the output voltage, and is configured to decrease a gain thereof in response to a drain current of the output transistor.
    Type: Application
    Filed: April 3, 2006
    Publication date: October 19, 2006
    Inventors: Yoshiki Takagi, Yusuke Minakuchi
  • Publication number: 20050231180
    Abstract: A constant voltage circuit that is capable of realizing high speed response with respect to an abrupt change in an input voltage or a load current is disclosed. The constant voltage circuit includes a first error amplifier with a high direct current gain and a second error amplifier with high speed responsiveness with respect to a change in an output voltage. The constant voltage circuit uses the first and second error amplifiers to conduct operation control of an output voltage control transistor in response to a change in the output voltage.
    Type: Application
    Filed: March 28, 2005
    Publication date: October 20, 2005
    Inventors: Toshihisa Nagata, Kohji Yoshii, Yusuke Minakuchi
  • Patent number: 4675593
    Abstract: A constant power voltage circuit includes a first transistor for generating a collector current, a second transistor for generating a collector current, a third transistor, the collector of which is connected to the collector of the first transistor, a fourth transistor, the collector of which is connected to the collector of the second transistor, an emitter-grounded amplifier circuit including a fifth transistor for providing a feedback loop, with a fifth transistor, the collector which is connected to a constant current circuit and the base current of the third and the fourth transistors, being outputted from the constant current circuit upon the application of a power source.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: June 23, 1987
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yusuke Minakuchi