Patents by Inventor Naoki Unou

Naoki Unou 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: 7816986
    Abstract: A PWM signal drives a pair of output transistors connected in series between a supply line and ground so that a push-pull current is output toward a speaker via a coil from a point connecting both output transistors. A current limiting resistor has one end connected to the supply line and between the other end and ground is provided a control transistor. Furthermore, a comparator compares the supply line voltage and a reference voltage and turns on the control transistor when the supply line voltage is higher than the reference voltage in the comparison result thereof.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: October 19, 2010
    Assignees: Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.
    Inventor: Naoki Unou
  • Publication number: 20090238382
    Abstract: The audio reproduction system amplifies and reproduces both a digital audio signal and an analog audio signal. After delta sigma modulation by a ?? modulator, the digital audio signal is pulse width modulated by a first PWM converter and supplied to a selector. The analog audio signal is compared with a PWM carrier signal by a second PWM converter, converted to a PWM signal, and supplied to the selector. A signal selected by the selector is then amplified by a class D amplifier.
    Type: Application
    Filed: March 19, 2009
    Publication date: September 24, 2009
    Applicants: SANYO ELECTRIC CO., LTD., SANYO SEMICONDUCTOR CO., LTD.
    Inventors: Naoki UNOU, Kazuhiko KONDO
  • Publication number: 20090237159
    Abstract: A PWM signal drives a pair of output transistors connected in series between a supply line and ground so that a push-pull current is output toward a speaker via a coil from a point connecting both output transistors. A current limiting resistor has one end connected to the supply line and between the other end and ground is provided a control transistor. Furthermore, a comparator compares the supply line voltage and a reference voltage and turns on the control transistor when the supply line voltage is higher than the reference voltage in the comparison result thereof.
    Type: Application
    Filed: March 19, 2009
    Publication date: September 24, 2009
    Applicants: SANYO ELECTRIC CO., LTD., SANYO SEMICONDUCTOR CO., LTD.
    Inventor: Naoki UNOU