Patents by Inventor Hiroaki Asazu

Hiroaki Asazu 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).

  • PWM power supply apparatus having a controlled duty ratio without causing overall system oscillation
    Patent number: 7893667
    Abstract: A direct-current stabilized power supply apparatus according to the present invention includes offsetting means that keeps a slope voltage (Vslp) shifted from the ground potential to a higher potential by a predetermined offset voltage ?V so that the lower limit level of the slope voltage (Vslp) is higher than that of an error voltage (Verr). With this configuration, it is possible to provide a direct-current stabilized power supply apparatus that can appropriately control a duty ratio without causing oscillation or the like in the overall system, and also to provide an electrical device incorporating such a power supply apparatus.
    Type: Grant
    Filed: August 2, 2006
    Date of Patent: February 22, 2011
    Assignee: Rohm Co., Ltd.
    Inventors: Atsushi Kitagawa, Hiroaki Asazu
  • Power supply apparatus
    Patent number: 7679351
    Abstract: A voltage generation unit generates a driving voltage for driving an LED. A first feedback path feeds back a voltage according to a voltage at one end of the LED. A second feedback path feeds back a voltage according to a voltage at the other end of the LED. A current driving circuit is provided on a path on which the voltage generation unit drives the LED. A control circuit controls the voltage generation unit so that one of first and second feedback voltages fed back by the first and second feedback paths, respectively is closer to a predetermined reference voltage.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: March 16, 2010
    Assignee: Rohm Co., Ltd.
    Inventors: Hiroaki Asazu, Kunihiro Komiya
  • POWER SUPPLY APPARATUS AND ELECTRICAL DEVICE THEREWITH
    Publication number: 20090284237
    Abstract: A direct-current stabilized power supply apparatus according to the present invention includes offsetting means that keeps a slope voltage (Vslp) shifted from the ground potential to a higher potential by a predetermined offset voltage ?V so that the lower limit level of the slope voltage (Vslp) is higher than that of an error voltage (Verr). With this configuration, it is possible to provide a direct-current stabilized power supply apparatus that can appropriately control a duty ratio without causing oscillation or the like in the overall system, and also to provide an electrical device incorporating such a power supply apparatus.
    Type: Application
    Filed: August 2, 2006
    Publication date: November 19, 2009
    Inventors: Atsushi Kitagawa, Hiroaki Asazu
  • Power supply apparatus
    Publication number: 20080007322
    Abstract: A voltage generation unit generates a driving voltage for driving an LED. A first feedback path feeds back a voltage according to a voltage at one end of the LED. A second feedback path feeds back a voltage according to a voltage at the other end of the LED. A current driving circuit is provided on a path on which the voltage generation unit drives the LED. A control circuit controls the voltage generation unit so that one of first and second feedback voltages fed back by the first and second feedback paths, respectively is closer to a predetermined reference voltage.
    Type: Application
    Filed: June 7, 2007
    Publication date: January 10, 2008
    Inventors: Hiroaki Asazu, Kunihiro Komiya