Patents by Inventor Shohichi Nitta

Shohichi Nitta 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: 7570034
    Abstract: A step-up/down DC-DC converter is disclosed that includes: a step-up/down part generating an output voltage by stepping up or down an input voltage; and a control part generating an error signal indicating an error between a voltage value obtained by dividing the output voltage and a predetermined reference voltage, and causing the step-up/down part to perform a step-up or step-down operation based on the comparison between the error signal and first and second triangle wave signals. The control part includes a first circuit generating the first triangle wave signal for step-down control and a second circuit generating the second triangle wave signal for step-up control. The first circuit generates a clock signal synchronized with the first triangle wave signal, and outputs the clock signal to the second circuit. The second circuit generates the second triangle wave signal synchronized with the first triangle wave signal based on the input clock signal.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: August 4, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
  • Patent number: 7468599
    Abstract: A DC power supply capable of obviating undue resetting and malfunction of CPU, immediately after starting the operation of a switching regulator, by inputting sleep signals input asynchronously during a switching cycle of the switching regulator. In the DC power supply adapted to apply a DC voltage to an output terminal by selectively switching between a first voltage from a switching regulator and a second voltage, the switching regulator includes a first switching element and a inductor serially connected between an input terminal for receiving an input voltage and an output terminal, and a second switching element for use in synchronous rectification between the first switching element and the ground, together with a first drive circuit for driving the first switching element, a second drive circuit for driving the second switching element, and a control circuit for controlling the first and second drive circuits.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: December 23, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
  • Publication number: 20080211474
    Abstract: A step-up/down DC-DC converter is disclosed that includes: a step-up/down part generating an output voltage by stepping up or down an input voltage; and a control part generating an error signal indicating an error between a voltage value obtained by dividing the output voltage and a predetermined reference voltage, and causing the step-up/down part to perform a step-up or step-down operation based on the comparison between the error signal and first and second triangle wave signals. The control part includes a first circuit generating the first triangle wave signal for step-down control and a second circuit generating the second triangle wave signal for step-up control. The first circuit generates a clock signal synchronized with the first triangle wave signal, and outputs the clock signal to the second circuit. The second circuit generates the second triangle wave signal synchronized with the first triangle wave signal based on the input clock signal.
    Type: Application
    Filed: January 25, 2008
    Publication date: September 4, 2008
    Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
  • Patent number: 7391189
    Abstract: A step-up/down DC-DC converter is disclosed that includes: a step-up/down part generating an output voltage by stepping up or down an input voltage; and a control part generating an error signal indicating an error between a voltage value obtained by dividing the output voltage and a predetermined reference voltage, and causing the step-up/down part to perform a step-up or step-down operation based on the comparison between the error signal and first and second triangle wave signals. The control part includes a first circuit generating the first triangle wave signal for step-down control and a second circuit generating the second triangle wave signal for step-up control. The first circuit generates a clock signal synchronized with the first triangle wave signal, and outputs the clock signal to the second circuit. The second circuit generates the second triangle wave signal synchronized with the first triangle wave signal based on the input clock signal.
    Type: Grant
    Filed: April 22, 2004
    Date of Patent: June 24, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
  • Patent number: 7199568
    Abstract: A DC power supply capable of obviating undue resetting and malfunction of CPU, immediately after starting the operation of a switching regulator, by inputting sleep signals input asynchronously during a switching cycle of the switching regulator. In the DC power supply adapted to apply a DC voltage to an output terminal by selectively switching between a first voltage from a switching regulator and a second voltage, the switching regulator includes a first switching element and a inductor serially connected between an input terminal for receiving an input voltage and an output terminal, and a second switching element for use in synchronous rectification between the first switching element and the ground, together with a first drive circuit for driving the first switching element, a second drive circuit for driving the second switching element, and a control circuit for controlling the first and second drive circuits.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: April 3, 2007
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
  • Publication number: 20070024260
    Abstract: A DC power supply capable of obviating undue resetting and malfunction of CPU, immediately after starting the operation of a switching regulator, by inputting sleep signals input asynchronously during a switching cycle of the switching regulator. In the DC power supply adapted to apply a DC voltage to an output terminal by selectively switching between a first voltage from a switching regulator and a second voltage, the switching regulator includes a first switching element and a inductor serially connected between an input terminal for receiving an input voltage and an output terminal, and a second switching element for use in synchronous rectification between the first switching element and the ground, together with a first drive circuit for driving the first switching element, a second drive circuit for driving the second switching element, and a control circuit for controlling the first and second drive circuits.
    Type: Application
    Filed: October 3, 2006
    Publication date: February 1, 2007
    Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
  • Publication number: 20060208718
    Abstract: A step-up/down DC-DC converter is disclosed that includes: a step-up/down part generating an output voltage by stepping up or down an input voltage; and a control part generating an error signal indicating an error between a voltage value obtained by dividing the output voltage and a predetermined reference voltage, and causing the step-up/down part to perform a step-up or step-down operation based on the comparison between the error signal and first and second triangle wave signals. The control part includes a first circuit generating the first triangle wave signal for step-down control and a second circuit generating the second triangle wave signal for step-up control. The first circuit generates a clock signal synchronized with the first triangle wave signal, and outputs the clock signal to the second circuit. The second circuit generates the second triangle wave signal synchronized with the first triangle wave signal based on the input clock signal.
    Type: Application
    Filed: April 22, 2004
    Publication date: September 21, 2006
    Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
  • Publication number: 20050052887
    Abstract: A DC power supply capable of obviating undue resetting and malfunction of CPU, immediately after starting the operation of a switching regulator, by inputting sleep signals input asynchronously during a switching cycle of the switching regulator. In the DC power supply adapted to apply a DC voltage to an output terminal by selectively switching between a first voltage from a switching regulator and a second voltage, the switching regulator includes a first switching element and a inductor serially connected between an input terminal for receiving an input voltage and an output terminal, and a second switching element for use in synchronous rectification between the first switching element and the ground, together with a first drive circuit for driving the first switching element, a second drive circuit for driving the second switching element, and a control circuit for controlling the first and second drive circuits.
    Type: Application
    Filed: September 1, 2004
    Publication date: March 10, 2005
    Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
  • Patent number: 6713992
    Abstract: A power supply apparatus includes a DC-to-DC converter performing a voltage conversion converting a voltage of a source power supplied from a direct current power source to a first predetermined voltage lower than the voltage of the source power and a voltage regulator carrying out a voltage regulation for regulating the first predetermined voltage of the source power output from the DC-to-DC converter to at least a second predetermined voltage lower than the first predetermined voltage.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: March 30, 2004
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Matsuo, Shohichi Nitta
  • Publication number: 20020121882
    Abstract: A power supply apparatus includes a DC-to-DC converter performing a voltage conversion converting a voltage of a source power supplied from a direct current power source to a first predetermined voltage lower than the voltage of the source power and a voltage regulator carrying out a voltage regulation for regulating the first predetermined voltage of the source power output from the DC-to-DC converter to at least a second predetermined voltage lower than the first predetermined voltage.
    Type: Application
    Filed: February 15, 2002
    Publication date: September 5, 2002
    Inventors: Masahiro Matsuo, Shohichi Nitta
  • Patent number: RE41304
    Abstract: A power supply apparatus includes a DC-to-DC converter performing a voltage conversion converting a voltage of a source power supplied from a direct current power source to a first predetermined voltage lower than the voltage of the source power and a voltage regulator carrying out a voltage regulation for regulating the first predetermined voltage of the source power output from the DC-to-DC converter to at least a second predetermined voltage lower than the first predetermined voltage.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: May 4, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Masahiro Matsuo, Shohichi Nitta