Patents by Inventor Akinobu Sawada

Akinobu Sawada 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).

  • Publication number: 20200158766
    Abstract: A zero-crossing detection circuit includes a zero-crossing detection unit arranged to compare a first monitoring target signal and a second monitoring target signal respectively input through diodes from a first node and a second node between which an AC signal is applied, so as to generate a first comparison signal, and a logic unit arranged to estimate a zero cross of the AC signal from the first comparison signal so as to generate a zero-crossing detection signal. The zero-crossing detection circuit preferably includes a monitoring unit arranged to adjust the first monitoring target signal and the second monitoring target signal to be suitable for input to the zero-crossing detection unit. The logic unit preferably counts a period of the first comparison signal and estimates a zero cross of the AC signal using a count value thereof.
    Type: Application
    Filed: July 25, 2018
    Publication date: May 21, 2020
    Applicant: Rohm Co., Ltd.
    Inventors: Satoru Nate, Akinobu Sawada, Natsuki Yamamoto
  • Publication number: 20190319527
    Abstract: There is provided a configuration of a switching control circuit for use with a switching power supply which generates an output voltage from an input voltage, the switching control circuit having an intermittent operation mode where an operation period in which a switching element of the switching power supply is switched and a pause period in which the switching element is not switched are repeated. The switching control circuit includes a prohibition part configured to prohibit starting a next operation period until a predetermined period of time elapses from a time that a current operation period starts, in the intermittent operation mode.
    Type: Application
    Filed: March 18, 2019
    Publication date: October 17, 2019
    Applicant: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Patent number: 9844108
    Abstract: A dimming circuit (A11) incorporated in a light-emitting-load driving device includes a pre-comparator (CMP21) arranged to compare a dimming signal (S20) with a threshold voltage (VthCMP) lower than an input buffer (A113x) of a dimming microcomputer (A113) so as to generate a comparison signal (S20y), and to transmit the comparison signal (S20y) instead of the dimming signal (S20) to the dimming microcomputer (A113).
    Type: Grant
    Filed: March 12, 2015
    Date of Patent: December 12, 2017
    Assignee: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Publication number: 20170215240
    Abstract: A dimming circuit (A11) incorporated in a light-emitting-load driving device includes a pre-comparator (CMP21) arranged to compare a dimming signal (S20) with a threshold voltage (VthCMP) lower than an input buffer (A113x) of a dimming microcomputer (A113) so as to generate a comparison signal (S20y), and to transmit the comparison signal (S20y) instead of the dimming signal (S20) to the dimming microcomputer (A113).
    Type: Application
    Filed: March 12, 2015
    Publication date: July 27, 2017
    Applicant: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Patent number: 9581655
    Abstract: A lighting apparatus of the present invention includes: a light source; a power source unit arranged to power the light source; a detector unit arranged to detect the deterioration of ability of the power source unit to power the light source; and a determination unit arranged to determine the life of the power source unit in response to the detector unit.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: February 28, 2017
    Assignee: Rohm Co., Ltd.
    Inventors: Masahide Tanaka, Mitsunori Nagashima, Akinobu Sawada
  • Patent number: 9553480
    Abstract: Disclosed is an electric power system including a first unit (for example, a unit 201) equipped with a first power source (for example, a solar panel (201b)), a first rechargeable battery (for example, a unit storage battery (201c)) to which an output of the first power source is input, and a first power consuming portion (not shown) to which an output of the first rechargeable battery is input; a second rechargeable battery (for example, a shared storage battery (202)); and an electric power line (for example, a shared electric power line (203)) for sharing electric power between the first rechargeable battery and the second rechargeable battery.
    Type: Grant
    Filed: December 16, 2010
    Date of Patent: January 24, 2017
    Assignee: Rohm Co., Ltd.
    Inventors: Akinobu Sawada, Kenichi Niiyama, Masahide Tanaka
  • Patent number: 9420659
    Abstract: An LED power supply device disclosed in the present specification includes a DC dimmer circuit that performs dimming control of an LED such that the higher a reference voltage variably controlled according to a dimmer signal is, the smaller a current flowing in the LED is. This configuration makes it possible to achieve fine dimming control.
    Type: Grant
    Filed: January 19, 2016
    Date of Patent: August 16, 2016
    Assignee: Rohm Co., Ltd.
    Inventors: Kotaro Shibata, Akinobu Sawada
  • Patent number: 9374083
    Abstract: The switching current control circuit includes a switching pulse supply circuit, a comparator circuit, and analog circuit unit, a digital circuit unit, etc. The A/D converter (2) detects a load current in an ON period of a switching pulse as a detected current, and converts it into digital data. The arithmetic control circuit (3) calculates a lower limit of the detected current for providing a timing of switching from OFF to ON of the switching pulse, based on the converted data. Continuation/discontinuous modes are determined whether the lower limit is equal to or greater than 0.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: June 21, 2016
    Assignee: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Publication number: 20160150613
    Abstract: An LED power supply device disclosed in the present specification includes a DC dimmer circuit that performs dimming control of an LED such that the higher a reference voltage variably controlled according to a dimmer signal is, the smaller a current flowing in the LED is. This configuration makes it possible to achieve fine dimming control.
    Type: Application
    Filed: January 19, 2016
    Publication date: May 26, 2016
    Inventors: Kotaro Shibata, Akinobu Sawada
  • Patent number: 9271365
    Abstract: An LED power supply device disclosed in the present specification includes a DC dimmer circuit that performs dimming control of an LED such that the higher a reference voltage variably controlled according to a dimmer signal is, the smaller a current flowing in the LED is. This configuration makes it possible to achieve fine dimming control.
    Type: Grant
    Filed: September 29, 2014
    Date of Patent: February 23, 2016
    Assignee: Rohm Co., Ltd.
    Inventors: Kotaro Shibata, Akinobu Sawada
  • Patent number: 9101011
    Abstract: A lighting system has a solar power generation section, a control section which generates a control signal based on the output of the solar power generation section, a power conversion section which converts a direct-current electric power input thereto to output a direct-current electric power, and a lighting section which is driven by the direct-current electric power output from the power conversion section.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: August 4, 2015
    Assignee: Rohm Co., Ltd.
    Inventors: Akinobu Sawada, Koji Taniuchi
  • Patent number: 9101008
    Abstract: A light emitter driving device has a decoder portion which monitors a rectified voltage and generates a dimming signal, and a drive current control portion which controls a drive current to a light emitter according to the dimming signal. The decoder portion has a comparator which compares the rectified voltage with a predetermined threshold voltage to generate a comparison signal, a sampling counter which measures high-level and low-level periods of the comparison signal, a duty calculation portion which calculates the duty of the rectified voltage based on the output of the sampling counter, a filter calculation portion which excludes sporadic variation in duty by applying digital filtering to the output of the duty calculation portion, and a dimming signal generation portion which generates the dimming signal based on the output of the filter calculation portion.
    Type: Grant
    Filed: November 12, 2014
    Date of Patent: August 4, 2015
    Assignee: Rohm Co., Ltd.
    Inventors: Takeshi Sumitani, Akinobu Sawada
  • Patent number: 9066384
    Abstract: The light emitting device control circuit device 100 in accordance with the disclosure includes a power source V1, a transistor TR1, a light emitting unit EU1, switches S1 to S17, constant current sources CC1 to CC17, and a controller 110. A switching voltage Vs1 is supplied from the controller 110 to turn ON or turn OFF the transistor TR intermittently, a pulse voltage is supplied to a pulse voltage supplying line Y1 connected to a drain terminal D of the transistor TR1. The driving signals SP1 to SP17 are sequentially supplied to the switches S1 to S17 to turn ON or turn OFF them (i.e., time division drive). The light emitting devices A1 to A17 are driven sequentially by a pulse current (i.e., time division drive) when a high voltage is supplied to the pulse voltage supplying line Y1 and when the driving signals SP1 to SP17 are turned ON.
    Type: Grant
    Filed: October 2, 2013
    Date of Patent: June 23, 2015
    Assignee: Rohm Co., Ltd.
    Inventors: Hidekazu Kikuchi, Akinobu Sawada
  • Publication number: 20150137687
    Abstract: An LED power supply device disclosed in the present specification includes a DC dimmer circuit that performs dimming control of an LED such that the higher a reference voltage variably controlled according to a dimmer signal is, the smaller a current flowing in the LED is. This configuration makes it possible to achieve fine dimming control.
    Type: Application
    Filed: September 29, 2014
    Publication date: May 21, 2015
    Inventors: Kotaro Shibata, Akinobu Sawada
  • Publication number: 20150069929
    Abstract: A light emitter driving device has a decoder portion which monitors a rectified voltage and generates a dimming signal, and a drive current control portion which controls a drive current to a light emitter according to the dimming signal. The decoder portion has a comparator which compares the rectified voltage with a predetermined threshold voltage to generate a comparison signal, a sampling counter which measures high-level and low-level periods of the comparison signal, a duty calculation portion which calculates the duty of the rectified voltage based on the output of the sampling counter, a filter calculation portion which excludes sporadic variation in duty by applying digital filtering to the output of the duty calculation portion, and a dimming signal generation portion which generates the dimming signal based on the output of the filter calculation portion.
    Type: Application
    Filed: November 12, 2014
    Publication date: March 12, 2015
    Inventors: Takeshi Sumitani, Akinobu Sawada
  • Patent number: 8922137
    Abstract: A lighting apparatus includes an illuminance sensor, a dimming control device and a light source. The lighting apparatus calculates a light output characteristic of the light source based on an illuminance measurement value when the light source is turned off and an illuminance measurement value when the light source is lit with a predetermined output, and calculates an ambient illuminance based on the light output characteristic. The illuminance measurement by the illuminance sensor is performed every predetermined period, and dimming control is performed on the light source based on the calculated ambient illuminance.
    Type: Grant
    Filed: August 10, 2010
    Date of Patent: December 30, 2014
    Assignee: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Patent number: 8922135
    Abstract: A light emitter driving device has a decoder portion which monitors a rectified voltage and generates a dimming signal, and a drive current control portion which controls a drive current to a light emitter according to the dimming signal. The decoder portion has a comparator which compares the rectified voltage with a predetermined threshold voltage to generate a comparison signal, a sampling counter which measures high-level and low-level periods of the comparison signal, a duty calculation portion which calculates the duty of the rectified voltage based on the output of the sampling counter, a filter calculation portion which excludes sporadic variation in duty by applying digital filtering to the output of the duty calculation portion, and a dimming signal generation portion which generates the dimming signal based on the output of the filter calculation portion.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: December 30, 2014
    Assignee: Rohm Co., Ltd.
    Inventors: Takeshi Sumitani, Akinobu Sawada
  • Patent number: 8890441
    Abstract: A load driving device has a switch N1, a driver that performs on/off control of the switch in accordance with SWON, a comparator that compares Vdet1 with Vth, and based on a result of the comparison, generates IPEAKDET, an ADC that converts Vdet1 into ADCOUT, a DAC that converts IPEAKSET into Vth, and a logic portion that, upon receiving inputs of IPEAKDET and ADCOUT, outputs SWON and IPEAKSET. The logic portion includes a computation circuit that calculates Y1 by using a computation equation expressed by Y1=AVE×?+?×Ton/2 (where Y1: a signal value of IPEAKSET; AVE: an average current set value of an output current; ?: an adjustment coefficient for AVE; Ton: an on period; ?: a change rate of AVCOUT). The computation circuit determines ? in accordance with computation mode setting signals ISO and PFC.
    Type: Grant
    Filed: September 12, 2013
    Date of Patent: November 18, 2014
    Assignee: Rohm Co., Ltd.
    Inventor: Akinobu Sawada
  • Publication number: 20140197840
    Abstract: A lighting apparatus of the present invention includes: a light source; a power source unit arranged to power the light source; a detector unit arranged to detect the deterioration of ability of the power source unit to power the light source; and a determination unit arranged to determine the life of the power source unit in response to the detector unit.
    Type: Application
    Filed: March 18, 2014
    Publication date: July 17, 2014
    Applicant: Rohm Co., Ltd.
    Inventors: Masahide Tanaka, Mitsunori Nagashima, Akinobu Sawada
  • Patent number: 8710995
    Abstract: A lighting apparatus of the present invention includes: a light source; a power source unit arranged to power the light source; a detector unit arranged to detect the deterioration of ability of the power source unit to power the light source; and a determination unit arranged to determine the life of the power source unit in response to the detector unit.
    Type: Grant
    Filed: May 19, 2011
    Date of Patent: April 29, 2014
    Assignee: Rohm Co., Ltd.
    Inventors: Masahide Tanaka, Mitsunori Nagashima, Akinobu Sawada