Patents by Inventor Keisuke Sakai

Keisuke Sakai 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: 12290967
    Abstract: An object of the invention is to provide a method for conditioning a surface of a molded article. The present invention relates to a combination of a mold used for curing a thermosetting resin and a release film placed between the thermosetting resin and the mold during the curing. The release film comprises a base layer formed of a thermoplastic resin and a surface layer formed of a particle-containing fluororesin and laminated to the face which is placed during the curing on the side of the thermosetting resin among the two faces of the base layer. The mold has an irregularity formed on the face brought into contact with the release film during the curing.
    Type: Grant
    Filed: September 24, 2019
    Date of Patent: May 6, 2025
    Assignee: KOBAYASHI & CO., LTD.
    Inventors: Keisuke Sakai, Nanae Tanaka, Kenji Miyashita, Go Kobayashi
  • Patent number: 12268039
    Abstract: A light emitting device has a substrate, a plurality of first light emitting elements, each of which is mounted on the substrate, has a first LED die, and emits light having a first wavelength, a first light transmitting layer arranged so as to cover the plurality of first light emitting elements, the first light transmitting layer transmitting light emitted from the plurality of first light emitting elements, a second light transmitting layer arranged so as to cover the first light transmitting layer, the second light transmitting layer transmitting light that has transmitted through the first light transmitting layer, and a reflector having an upwardly bulging curved surface at an upper portion of an inner wall that the first light transmitting layer and the second light transmitting layer contact, the reflector being arranged on the substrate so as to surround the plurality of first light emitting elements and reflecting light emitted from the first light emitting elements, wherein the thickness T between
    Type: Grant
    Filed: December 27, 2022
    Date of Patent: April 1, 2025
    Assignees: Citizen Electronics Co., Ltd., Citizen Watch Co., Ltd.
    Inventor: Keisuke Sakai
  • Publication number: 20240421274
    Abstract: A light emitting device has a substrate, a plurality of first light emitting elements, each of which is mounted on the substrate, has a first LED die, and emits light having a first wavelength, a first light transmitting layer arranged so as to cover the plurality of first light emitting elements, the first light transmitting layer transmitting light emitted from the plurality of first light emitting elements, a second light transmitting layer arranged so as to cover the first light transmitting layer, the second light transmitting layer transmitting light that has transmitted through the first light transmitting layer, and a reflector having an upwardly bulging curved surface at an upper portion of an inner wall that the first light transmitting layer and the second light transmitting layer contact, the reflector being arranged on the substrate so as to surround the plurality of first light emitting elements and reflecting light emitted from the first light emitting elements, wherein the thickness T between
    Type: Application
    Filed: December 27, 2022
    Publication date: December 19, 2024
    Inventor: Keisuke SAKAI
  • Patent number: 12112957
    Abstract: To provide a release film not to contaminate a mold or a molded article. The present invention provides a release film comprising a base layer formed of an easily moldable polyethylene terephthalate resin and surface layers laminated on two faces of the base layer and formed of a fluororesin. The present invention also provides a method of manufacturing a release film. The method comprises an applying step of applying a fluororesin composition onto two faces of a base layer formed of an easily moldable polyethylene terephthalate resin and, after the applying step, a curing step of curing the fluororesin composition. By molding with the release film, contamination of a mold or a molded article is prevented. The release film can be used in molding multiple times.
    Type: Grant
    Filed: April 8, 2019
    Date of Patent: October 8, 2024
    Assignee: KOBAYASHI & CO., LTD.
    Inventors: Keisuke Sakai, Norifumi Iwawaki, Nanae Tanaka, Satoshi Hiramatsu, Akane Kawafuchi
  • Patent number: 11919205
    Abstract: The objective of the present invention is to provide a mold-release film that docs not contaminate the mold or the formed body. This invention provides a mold-release film comprising a base material layer formed from a thermoplastic resin, and a surface layer formed from a resin composition layered on at least one surface of the base material layer. The mold-release film has a trouser tear strength, conforming to JIS K 7128-1, of 5 N/mm or stronger. The resin composition has a peel strength of 15 mN/30 mm or weaker, as measured at 175° C. in accordance with JIS Z0237. The resin composition has an elongation at break of 70% or greater, as measured at 175° C. in accordance with JIS K 7127.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: March 5, 2024
    Assignee: KOBAYASHI & CO., LTD.
    Inventors: Keisuke Sakai, Nanae Tanaka
  • Patent number: 11920012
    Abstract: To provide a release film not to contaminate a mold or a molded article. The present invention provides a release film comprising, an oligomer bleeding prevention layer formed of an acrylic resin or a siloxane resin and laminated on a first face of a base layer that is formed of a polyethylene terephthalate resin; a surface layer formed of a fluororesin and laminated on the oligomer bleeding prevention layer; and a surface layer formed of a fluororesin and laminated on a second face of the base layer, or an oligomer bleeding prevention layer formed of an acrylic resin or a siloxane resin and laminated on a second face of the base layer, and a surface layer formed of a fluororesin and laminated on the oligomer bleeding prevention layer that is laminated on the second face.
    Type: Grant
    Filed: April 8, 2019
    Date of Patent: March 5, 2024
    Assignee: KOBAYASHI & CO., LTD.
    Inventors: Keisuke Sakai, Norifumi Iwawaki, Nanae Tanaka, Satoshi Hiramatsu, Akane Kawafuchi
  • Patent number: 11817530
    Abstract: A light emitting device includes a substrate, a plurality of first light emitting elements mounted on the substrate, including first LED dies, and emitting light having a first wavelength, and a light guide layer arranged so as to cover the plurality of first light emitting elements, and guiding the light from the plurality of first light emitting elements, wherein when LG1 is a distance between the first LED dies, and ?c is a critical angle of the light emitted from the light guide layer to the air, and a thickness T between the upper surfaces of the first light emitting elements and the upper surface of the light guide layer is equal to or longer than T1 indicated by T1=LG1/(2tan ?c).
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: November 14, 2023
    Assignees: Citizen Electronics Co., Ltd., Citizen Watch Co., Ltd.
    Inventor: Keisuke Sakai
  • Publication number: 20230231082
    Abstract: A light emitting device includes a substrate, a plurality of first light emitting elements mounted on the substrate, including first LED dies, and emitting light having a first wavelength, and a light guide layer arranged so as to cover the plurality of first light emitting elements, and guiding the light from the plurality of first light emitting elements, wherein when LG1 is a distance between the first LED dies, and ?c is a critical angle of the light emitted from the light guide layer to the air, and a thickness T between the upper surfaces of the first light emitting elements and the upper surface of the light guide layer is equal to or longer than T1 indicated by T1=LG1/(2tan ?c).
    Type: Application
    Filed: June 28, 2021
    Publication date: July 20, 2023
    Inventor: Keisuke SAKAI
  • Publication number: 20230054528
    Abstract: The objective of the present invention is to provide a mold-release film that docs not contaminate the mold or the formed body. This invention provides a mold-release film comprising a base material layer formed from a thermoplastic resin, and a surface layer formed from a resin composition layered on at least one surface of the base material layer. The mold-release film has a trouser tear strength, conforming to JIS K 7128-1, of 5 N/mm or stronger. The resin composition has a peel strength of 15 mN/30 mm or weaker, as measured at 175° C. in accordance with JIS Z0237. The resin composition has an elongation at break of 70% or greater, as measured at 175° C. in accordance with JIS K 7127.
    Type: Application
    Filed: June 29, 2020
    Publication date: February 23, 2023
    Applicant: KOBAYASHI & CO.,LTD.
    Inventors: Keisuke SAKAI, Nanae TANAKA
  • Publication number: 20220396011
    Abstract: To provide a release film having an electrostatic dissipative property. The present invention provides a release film comprising a base layer formed of a polyester resin and a surface layer formed of a tetrafluoroethylene resin that comprises an electrically conductive filler, and the release film has a surface resistivity Rs of 1×1011? or less. Preferably, the electrically conductive filler comprises carbon black, and the tetrafluoroethylene resin further comprises particles having an average particle size of 1 ?m to 15 ?m determined by laser diffraction particle size analysis.
    Type: Application
    Filed: March 6, 2020
    Publication date: December 15, 2022
    Applicant: KOBAYASHI & CO., LTD.
    Inventors: Keisuke SAKAI, Nanae TANAKA
  • Publication number: 20220162479
    Abstract: An object of the invention is to provide a film having excellent weatherability. The present invention provides a film comprising: a base layer formed of a thermoplastic resin, and a fluororesin layer laminated to one face of the base layer, wherein the fluororesin layer contains a tetrafluoroethylene resin and a photostabilizer. The present invention also provides a method of manufacturing a fluororesin composition suitable for manufacturing the film. The method of manufacturing comprises a dissolving step in which a photostabilizer is dissolved in ester-based, ketone-based, or aromatic solvent to obtain a solution and a mixing step in which the solution is mixed with a fluororesin comprising tetrafluoroethylene resin.
    Type: Application
    Filed: March 6, 2020
    Publication date: May 26, 2022
    Applicant: KOBAYASHI & CO.,LTD.
    Inventors: Keisuke SAKAI, Nanae TANAKA
  • Publication number: 20220152882
    Abstract: An object of the invention is to provide a method for conditioning a surface of a molded article. The present invention relates to a combination of a mold used for curing a thermosetting resin and a release film placed between the thermosetting resin and the mold during the curing. The release film comprises a base layer formed of a thermoplastic resin and a surface layer formed of a particle-containing fluororesin and laminated to the face which is placed during the curing on the side of the thermosetting resin among the two faces of the base layer. The mold has an irregularity formed on the face brought into contact with the release film during the curing.
    Type: Application
    Filed: September 24, 2019
    Publication date: May 19, 2022
    Applicant: KOBAYASHI & CO.,LTD.
    Inventors: Keisuke SAKAI, Nanae TANAKA, Kenji MIYASHITA, Go KOBAYASHI
  • Patent number: 11149818
    Abstract: A rotary device includes two rotatable rotors and two stopper mechanisms. The first and second stopper mechanisms restrict relative rotation between the rotors. The first stopper mechanism includes a first protruding member and a first contact surface. The first protruding member includes an elastic outer peripheral part. The first contact surface is disposed at an interval from the first protruding member. The first protruding member contacts the first contact surface when a torsion angle between the rotors reaches a first angle. The second stopper mechanism includes a second protruding member and a second contact surface. The second protruding member includes an outer peripheral part having higher stifffiess than that of the first protruding member. The second contact surface is disposed at an interval from the second protruding member. The second protruding member contacts the second contact surface when the torsion angle reaches a second angle greater than the first angle.
    Type: Grant
    Filed: December 26, 2019
    Date of Patent: October 19, 2021
    Assignee: EXEDY CORPORATION
    Inventors: Yusuke Tomita, Keisuke Sakai
  • Publication number: 20210257228
    Abstract: To provide a release film not to contaminate a mold or a molded article. The present invention provides a release film comprising a base layer formed of an easily moldable polyethylene terephthalate resin and surface layers laminated on two faces of the base layer and formed of a fluororesin. The present invention also provides a method of manufacturing a release film. The method comprises an applying step of applying a fluororesin composition onto two faces of a base layer formed of an easily moldable polyethylene terephthalate resin and, after the applying step, a curing step of curing the fluororesin composition. By molding with the release film, contamination of a mold or a molded article is prevented. The release film can be used in molding multiple times.
    Type: Application
    Filed: April 8, 2019
    Publication date: August 19, 2021
    Applicant: KOBAYASHI & CO.,LTD.
    Inventors: Keisuke SAKAI, Norifumi IWAWAKI, Nanae TANAKA, Satoshi HIRAMATSU, Akane KAWAFUCHI
  • Publication number: 20210253815
    Abstract: To provide a release film not to contaminate a mold or a molded article. The present invention provides a release film comprising, an oligomer bleeding prevention layer formed of an acrylic resin or a siloxane resin and laminated on a first face of a base layer that is formed of a polyethylene terephthalate resin; a surface layer formed of a fluororesin and laminated on the oligomer bleeding prevention layer; and a surface layer formed of a fluororesin and laminated on a second face of the base layer, or an oligomer bleeding prevention layer formed of an acrylic resin or a siloxane resin and laminated on a second face of the base layer, and a surface layer formed of a fluororesin and laminated on the oligomer bleeding prevention layer that is laminated on the second face.
    Type: Application
    Filed: April 8, 2019
    Publication date: August 19, 2021
    Applicant: KOBAYASHI & CO.,LTD.
    Inventors: Keisuke SAKAI, Norifumi IWAWAKI, Nanae TANAKA, Satoshi HIRAMATSU, Akane KAWAFUCHI
  • Publication number: 20200271189
    Abstract: A rotary device includes two rotatable rotors and two stopper mechanisms. The first and second stopper mechanisms restrict relative rotation between the rotors. The first stopper mechanism includes a first protruding member and a first contact surface. The first protruding member includes an elastic outer peripheral part. The first contact surface is disposed at an interval from the first protruding member. The first protruding member contacts the first contact surface when a torsion angle between the rotors reaches a first angle. The second stopper mechanism includes a second protruding member and a second contact surface. The second protruding member includes an outer peripheral part having higher stifffiess than that of the first protruding member. The second contact surface is disposed at an interval from the second protruding member. The second protruding member contacts the second contact surface when the torsion angle reaches a second angle greater than the first angle.
    Type: Application
    Filed: December 26, 2019
    Publication date: August 27, 2020
    Inventors: Yusuke TOMITA, Keisuke SAKAI
  • Patent number: 10495178
    Abstract: A torque fluctuation inhibiting device includes a mass body. The mass body disposed to be rotatable with a rotor and be rotatable relatively to the rotor. Each of a plurality of centrifugal elements is radially movable by a centrifugal force that acts thereon in rotation of the rotor and the mass body. When a relative displacement is produced between the rotor and the mass body in a rotational direction while the centrifugal force is acting on the each of the plurality of centrifugal elements, each of a plurality of cam mechanisms converts the centrifugal force into a circumferential force directed to reduce the relative displacement. A plurality of restriction members allow the plurality of centrifugal elements to move in actuation of the plurality of cam mechanisms, and restrict the plurality of centrifugal elements from moving radially inward in non-actuation of the plurality of cam mechanisms.
    Type: Grant
    Filed: August 7, 2018
    Date of Patent: December 3, 2019
    Assignee: EXEDY CORPORATION
    Inventors: Yusuke Tomita, Keisuke Sakai
  • Patent number: 10433381
    Abstract: An LED drive circuit in which a bright change of an LED is suppressed even if the voltage of a full-wave rectified waveform fluctuates is provided. The LED drive circuit includes a bridge rectifier circuit, an LED string made up by a plurality of LEDs being connected in series and supplied with a current from the bridge rectifier circuit, and a current limiting circuit that has a current input terminal and a current output terminal connected onto a path that starts from the bridge rectifier circuit and returns to the bridge rectifier circuit via the LED string, which limits a current that flows through the LED string to an upper limit current value or smaller, and further, which decreases the upper limit current value in accordance with the amount of rise in the voltage when the voltage at the current input terminal viewed from the current output terminal rises.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: October 1, 2019
    Assignees: CITIZEN WATCH CO., LTD., CITIZEN ELECTRONICS CO., LTD.
    Inventors: Keisuke Sakai, Takashi Akiyama
  • Publication number: 20190063549
    Abstract: A torque fluctuation inhibiting device includes a mass body. The mass body disposed to be rotatable with a rotor and be rotatable relatively to the rotor. Each of a plurality of centrifugal elements is radially movable by a centrifugal force that acts thereon in rotation of the rotor and the mass body. When a relative displacement is produced between the rotor and the mass body in a rotational direction while the centrifugal force is acting on the each of the plurality of centrifugal elements, each of a plurality of cam mechanisms converts the centrifugal force into a circumferential force directed to reduce the relative displacement. A plurality of restriction members allow the plurality of centrifugal elements to move in actuation of the plurality of cam mechanisms, and restrict the plurality of centrifugal elements from moving radially inward in non-actuation of the plurality of cam mechanisms.
    Type: Application
    Filed: August 7, 2018
    Publication date: February 28, 2019
    Inventors: Yusuke TOMITA, Keisuke SAKAI
  • Patent number: D929899
    Type: Grant
    Filed: November 1, 2019
    Date of Patent: September 7, 2021
    Inventors: Shigeo Hirata, Keisuke Sakai, Hikaru Iwasaki, Kuniaki Toyooka, Naoki Nagatsu