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).
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Patent number: 7570034Abstract: 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: GrantFiled: January 25, 2008Date of Patent: August 4, 2009Assignee: Ricoh Company, Ltd.Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
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Patent number: 7468599Abstract: 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: GrantFiled: October 3, 2006Date of Patent: December 23, 2008Assignee: Ricoh Company, Ltd.Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
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Publication number: 20080211474Abstract: 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: ApplicationFiled: January 25, 2008Publication date: September 4, 2008Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
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Patent number: 7391189Abstract: 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: GrantFiled: April 22, 2004Date of Patent: June 24, 2008Assignee: Ricoh Company, Ltd.Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
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Patent number: 7199568Abstract: 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: GrantFiled: September 1, 2004Date of Patent: April 3, 2007Assignee: Ricoh Company, Ltd.Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
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Publication number: 20070024260Abstract: 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: ApplicationFiled: October 3, 2006Publication date: February 1, 2007Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
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Publication number: 20060208718Abstract: 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: ApplicationFiled: April 22, 2004Publication date: September 21, 2006Inventors: Shohichi Nitta, Masahiro Matsuo, Ritsuko Nomura
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Publication number: 20050052887Abstract: 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: ApplicationFiled: September 1, 2004Publication date: March 10, 2005Inventors: Masahiro Matsuo, Shohichi Nitta, Tomonari Katoh
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Patent number: 6713992Abstract: 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: GrantFiled: February 15, 2002Date of Patent: March 30, 2004Assignee: Ricoh Company, Ltd.Inventors: Masahiro Matsuo, Shohichi Nitta
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Publication number: 20020121882Abstract: 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: ApplicationFiled: February 15, 2002Publication date: September 5, 2002Inventors: Masahiro Matsuo, Shohichi Nitta
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Patent number: RE41304Abstract: 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: GrantFiled: March 28, 2006Date of Patent: May 4, 2010Assignee: Ricoh Company, Ltd.Inventors: Masahiro Matsuo, Shohichi Nitta