Patents by Inventor Masato Aoki

Masato Aoki 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: 9647170
    Abstract: The present techniques provide a method for producing a Group III nitride semiconductor light-emitting device, with suppression of an increase in polarity inversion defect density. The production method includes an n-type semiconductor layer formation step, a light-emitting layer formation step, and a p-type semiconductor layer formation step. The p-type semiconductor layer formation step includes a p-type cladding layer formation step. The p-type cladding layer formation step includes a first p-type semiconductor layer formation step for forming a p-type AlGaN layer, a first semiconductor layer growth intermission step after the first p-type semiconductor layer formation step, and a p-type InGaN layer formation step after the first semiconductor layer growth intermission step. In the first semiconductor layer growth intermission step, a mixture of nitrogen gas and hydrogen gas is supplied to the substrate.
    Type: Grant
    Filed: February 6, 2015
    Date of Patent: May 9, 2017
    Assignee: TOYODA GOSEI CO., LTD.
    Inventor: Masato Aoki
  • Patent number: 9584049
    Abstract: An H-bridge circuit controls a motor and includes a first series circuit of switching elements and a second series circuit of switching elements connected in parallel to the first series circuit. A motor driving control method includes a step of turning each of the switching elements Q2, Q3 off and turning-on or performing PWM control on the switching element Q1 and also turning the switching elements Q4 on; a step of performing PWM control on Q1; a step of turning off Q1; a step of repeating for a predetermined number of times a first kickback suppression period during which Q2 is turned on and Q4 is turned off and a second kickback suppression period during which Q2 is turned off and Q4 is turned on; and a step of turning Q2 on and turning on or performing PWM control on Q3.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: February 28, 2017
    Assignee: Minebea Co., Ltd.
    Inventor: Masato Aoki
  • Patent number: 9543866
    Abstract: A motor drive controller is for controlling a motor having multiple phases and includes: a comparison reference voltage generator that generates a predetermined constant voltage as a comparison reference voltage; a counter-electromotive voltage comparator that compares the comparison reference voltage with a counter-electromotive voltage of each phase of the motor; and a rotation state detector that detects a rotation state of the motor based on positive/negative polarities of counter-electromotive voltages of other phases with respect to the comparison reference voltage at the time of an occurrence of a zero cross between the counter-electromotive voltage of any one phase and the comparison reference voltage.
    Type: Grant
    Filed: November 25, 2015
    Date of Patent: January 10, 2017
    Assignee: Minebea Co., Ltd.
    Inventors: Hiroyuki Kaidu, Masato Aoki
  • Publication number: 20160368364
    Abstract: A vehicle structure includes a cooling device, an air guide member, and a horn. The cooling device is cooled with a flow of moving air which a vehicle receives while traveling. The air guide member guides the moving air into the cooling device. The air guide member has a single opening in a front of the vehicle. The horn is disposed at a side of the air guide member. The cooling device and the horn are arranged in a vehicle-width direction. The cooling device and the horn face the single opening viewed form the front of the vehicle.
    Type: Application
    Filed: June 3, 2016
    Publication date: December 22, 2016
    Applicant: HONDA MOTOR CO., LTD.
    Inventor: Masato AOKI
  • Publication number: 20160336894
    Abstract: A motor drive controller includes: a motor driver that applies a voltage to each phase of a motor to rotate; a rotational position detector that detects rotational position of the motor and generates rotational position information indicating the rotational position; and a controller that outputs, to the motor driver, driving control signals for repeatedly adjusting an advance angle and a lag angle at energization switching of the each phase of the motor in a prescribed pattern based on the rotational position information generated by the rotational position detector.
    Type: Application
    Filed: May 11, 2016
    Publication date: November 17, 2016
    Inventors: Hiroyuki KAIDU, Yuji OMURA, Kouji KEBUKAWA, Masato AOKI
  • Publication number: 20160156295
    Abstract: A motor drive controller is for controlling a motor having multiple phases and includes: a comparison reference voltage generator that generates a predetermined constant voltage as a comparison reference voltage; a counter-electromotive voltage comparator that compares the comparison reference voltage with a counter-electromotive voltage of each phase of the motor; and a rotation state detector that detects a rotation state of the motor based on positive/negative polarities of counter-electromotive voltages of other phases with respect to the comparison reference voltage at the time of an occurrence of a zero cross between the counter-electromotive voltage of any one phase and the comparison reference voltage.
    Type: Application
    Filed: November 25, 2015
    Publication date: June 2, 2016
    Inventors: Hiroyuki KAIDU, Masato AOKI
  • Publication number: 20160149526
    Abstract: A motor drive controller is provided with: a motor drive circuit that drives a motor and having a position detector that detects a position of a rotor of the motor and outputs a position detection signal; a motor control circuit that generates a rotation pulse signal based on the position detection signal output by the motor drive circuit; and a microcomputer that is provided with at least one timer and outputs a conversion signal that is obtained by multiplying the rotation pulse signal by n, where n is a natural number equal to or greater than two.
    Type: Application
    Filed: November 12, 2015
    Publication date: May 26, 2016
    Inventors: Hiroyuki KAIDU, Masato AOKI
  • Patent number: 9263639
    Abstract: The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved emission output. The light-emitting device comprises an n-type contact layer on which an n-electrode is formed, a light-emitting layer, an n-type cladding layer formed between the light-emitting layer and the n-type contact layer. The n-type cladding layer has a structure of at least two layers including a first n-type cladding layer closer to the light-emitting layer and a second n-type cladding layer farther from the light-emitting layer than the first n-type cladding layer. The first n-type cladding layer has a Si concentration higher than that of the second n-type cladding layer, and the first n-type cladding layer has a thickness smaller than that of the second n-type cladding layer.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: February 16, 2016
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Masato Aoki, Yoshiki Saito
  • Patent number: 9219436
    Abstract: A driving control device of a motor includes: a motor driving unit, which drives a motor in response to a driving control signal; and a control unit, which determines an energization pattern applied to an armature coil based on a detected rotational position of the rotor, wherein the control unit starts rotation control by a preset first energization pattern when activating of the motor, wherein when a predetermined time period has elapsed, the control unit adjusts energizing timing to be a timing, at which a short of each phase is not caused at switching of the energization pattern, and then outputs the driving control signal to the motor driving unit so that the rotation control is switched to rotation control of a second energization pattern, which has a predetermined advanced angle amount with respect to the first energization pattern.
    Type: Grant
    Filed: September 11, 2013
    Date of Patent: December 22, 2015
    Assignee: Minebea Co., Ltd.
    Inventor: Masato Aoki
  • Publication number: 20150349678
    Abstract: An H-bridge circuit controls a motor and includes a first series circuit of switching elements and a second series circuit of switching elements connected in parallel to the first series circuit. A motor driving control method includes a step of turning each of the switching elements Q2, Q3 off and turning-on or performing PWM control on the switching element Q1 and also turning the switching elements Q4 on; a step of performing PWM control on Q1; a step of turning off Q1; a step of repeating for a predetermined number of times a first kickback suppression period during which Q2 is turned on and Q4 is turned off and a second kickback suppression period during which Q2 is turned off and Q4 is turned on; and a step of turning Q2 on and turning on or performing PWM control on Q3.
    Type: Application
    Filed: May 22, 2015
    Publication date: December 3, 2015
    Inventor: Masato AOKI
  • Publication number: 20150236193
    Abstract: The present techniques provide a method for producing a Group III nitride semiconductor light-emitting device, with suppression of an increase in polarity inversion defect density. The production method includes an n-type semiconductor layer formation step, a light-emitting layer formation step, and a p-type semiconductor layer formation step. The p-type semiconductor layer formation step includes a p-type cladding layer formation step. The p-type cladding layer formation step includes a first p-type semiconductor layer formation step for forming a p-type AlGaN layer, a first semiconductor layer growth intermission step after the first p-type semiconductor layer formation step, and a p-type InGaN layer formation step after the first semiconductor layer growth intermission step. In the first semiconductor layer growth intermission step, a mixture of nitrogen gas and hydrogen gas is supplied to the substrate.
    Type: Application
    Filed: February 6, 2015
    Publication date: August 20, 2015
    Inventor: Masato AOKI
  • Patent number: 9007011
    Abstract: A driving control device of a brushless motor includes an inverter circuit having: first arm-side switching elements that are connected between respective phases of respective armature coils of the brushless motor and one terminal of a power supply; and second arm-side switching elements that are connected between respective phases of the respective armature coils and the other terminal of the power supply, and a control unit, wherein, in a short-circuit braking according to a short-circuit braking signal, the control unit outputs a signal of turning off all the first arm-side switching element and outputs a signal of controlling the at least one of the second arm-side switching elements to perform a switching operation and turning on the other second arm-side switching elements.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: April 14, 2015
    Assignee: Minebea Co., Ltd.
    Inventor: Masato Aoki
  • Patent number: 9000705
    Abstract: There is provided a power controller including a drive circuit connected to a DC power supply to apply a first voltage to the drive circuit and configured to supply power to an external load, a current detection circuit configured to detect a current flowing in the drive circuit by converting the current into a second voltage corresponding to the current, and a current-voltage control unit configured to generate a reference voltage corresponding to a limit value of the current flowing in the drive circuit when the first voltage is applied to the drive circuit, and configured to control the drive circuit to operate in a desired current according to the first voltage, based on a comparison result of the reference voltage and the second voltage.
    Type: Grant
    Filed: September 10, 2012
    Date of Patent: April 7, 2015
    Assignee: Minebea Co., Ltd.
    Inventors: Hiroyuki Kaidu, Masato Aoki
  • Publication number: 20150030046
    Abstract: The present invention provides a Group III nitride semiconductor light-emitting device exhibiting improved emission output. The light-emitting device comprises an n-type contact layer on which an n-electrode is formed, a light-emitting layer, an n-type cladding layer formed between the light-emitting layer and the n-type contact layer. The n-type cladding layer has a structure of at least two layers including a first n-type cladding layer closer to the light-emitting layer and a second n-type cladding layer farther from the light-emitting layer than the first n-type cladding layer. The first n-type cladding layer has a Si concentration higher than that of the second n-type cladding layer, and the first n-type cladding layer has a thickness smaller than that of the second n-type cladding layer.
    Type: Application
    Filed: July 11, 2014
    Publication date: January 29, 2015
    Inventors: Masato Aoki, Yoshiki Saito
  • Patent number: 8928001
    Abstract: A group III nitride compound semiconductor light emitting device that inhibits occurrence of dislocation in a strain relaxation layer in forming a group III nitride compound semiconductor layer on a thin GaN substrate, and a method for producing the same are provided. A light emitting device 100 comprises a support substrate 10, a GaN substrate 20, an n-type contact layer 30, a strain relaxation layer 40 (n-type InGaN layer), a light emitting layer 50, a p-type clad layer 60, and a p-type contact layer 70. The GaN substrate 20 has a thickness in a range of from 10 nm to 10 ?m. The strain relaxation layer 40 (n-type InGaN layer) has an In composition ratio X in a range of from larger than 0 to 3%.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: January 6, 2015
    Assignee: Toyoda Gosei Co., Ltd.
    Inventors: Yoshiki Saito, Yasuhisa Ushida, Masato Aoki
  • Patent number: 8889449
    Abstract: A method for producing a group III nitride semiconductor light-emitting device, by which a non-light-emitting region is easily formed, is disclosed. Mg is activated to convert a p-type layer into p-type, and a p-electrode is then formed on the p-type layer. An Ag paste is applied to a region on the p-electrode and overlapping an n-electrode formed in a subsequent step. Heat treatment is conducted to solidify the Ag paste, thereby forming an Ag paste solidified body. By this, a region overlapping the Ag paste solidified body in a planar view, of the p-type layer converts into a region having high resistance, and a high resistance region is formed. As a result, a region overlapping the high resistance region in a planar view, of a light-emitting layer becomes a non-light-emitting region.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: November 18, 2014
    Assignee: Toyoda Gosei Co., Ltd
    Inventors: Masato Aoki, Koichi Goshonoo, Satoshi Wada
  • Publication number: 20140139153
    Abstract: A driving control device of a motor includes: a motor driving unit, which drives a motor in response to a driving control signal; and a control unit, which determines an energization pattern applied to an armature coil based on a detected rotational position of the rotor, wherein the control unit starts rotation control by a preset first energization pattern when activating of the motor, wherein when a predetermined time period has elapsed, the control unit adjusts energizing timing to be a timing, at which a short of each phase is not caused at switching of the energization pattern, and then outputs the driving control signal to the motor driving unit so that the rotation control is switched to rotation control of a second energization pattern, which has a predetermined advanced angle amount with respect to the first energization pattern.
    Type: Application
    Filed: September 11, 2013
    Publication date: May 22, 2014
    Applicant: Minebea Co., Ltd.
    Inventor: Masato AOKI
  • Publication number: 20130330264
    Abstract: A crystal growth method, comprising the steps of: a) bringing a nitrogen material into a reaction vessel in which a mixed molten liquid comprising an alkaline metal and a group-III metal; and b) growing a crystal of a group-III nitride using the mixed molten liquid and the nitrogen material brought in by the step a) in the reaction vessel, wherein a provision is made such as to prevent a vapor of the alkaline metal from dispersing out of the reaction vessel.
    Type: Application
    Filed: August 14, 2013
    Publication date: December 12, 2013
    Applicant: Ricoh Company, Ltd.
    Inventors: Seiji SARAYAMA, Massahiko Shimada, Hisanori Yamane, Masato Aoki
  • Patent number: 8562737
    Abstract: A crystal growth method, comprising the steps of: a) bringing a nitrogen material into a reaction vessel in which a mixed molten liquid comprising an alkaline metal and a group-III metal; and b) growing a crystal of a group-III nitride using the mixed molten liquid and the nitrogen material brought in by the step a) in the reaction vessel, wherein a provision is made such as to prevent a vapor of the alkaline metal from dispersing out of the reaction vessel.
    Type: Grant
    Filed: June 13, 2008
    Date of Patent: October 22, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Seiji Sarayama, Masahiko Shimada, Hisanori Yamane, Masato Aoki
  • Patent number: D734432
    Type: Grant
    Filed: September 11, 2014
    Date of Patent: July 14, 2015
    Assignee: SMC Corporation
    Inventors: Hideharu Sato, Yoshitada Doi, Masato Aoki