Patents by Inventor Daisuke Ozaki

Daisuke Ozaki 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: 20260123031
    Abstract: Provided is a semiconductor device in which one mesa portion of two mesa portions in contact with a gate trench portion is an active mesa portion in which an emitter region of a first conductivity type having a doping concentration higher than that of a drift region is arranged in contact with the gate trench portion, the other mesa portion of two mesa portions in contact with the gate trench portion is a dummy mesa portion having no emitter region, and a dummy contact resistance which is a resistance of the dummy mesa portion and an emitter electrode is 1000 times or more as high as an active contact resistance which is a resistance of the active mesa portion and the emitter electrode.
    Type: Application
    Filed: December 29, 2025
    Publication date: April 30, 2026
    Inventors: Yosuke SAKURAI, Akio YAMANO, Seiji NOGUCHI, Ryutaro HAMASAKI, Takuya YAMADA, Daisuke OZAKI
  • Patent number: 12575149
    Abstract: Provided is a semiconductor device comprising a semiconductor substrate, the semiconductor substrate comprising an active portion, a second conductivity type circumferential well region surrounding the active portion in a top view, and a trench portion provided in the active portion on an upper surface of the semiconductor substrate, wherein the active portion includes a center portion including a first conductivity type emitter region, and a circumferential portion surrounding the center portion, wherein the center portion includes a second conductivity type active side bottom region provided across bottoms of at least two of the trench portion, the circumferential portion includes a second conductivity type circumferential side bottom region electrically connected to the circumferential well region, facing the active side bottom region, and provided at the bottom of the trench portion, and the active side bottom region and the circumferential side bottom region are provided apart from each other.
    Type: Grant
    Filed: December 19, 2022
    Date of Patent: March 10, 2026
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Daisuke Ozaki, Seiji Noguchi, Yosuke Sakurai, Ryutaro Hamasaki, Takuya Yamada, Yoshihiro Ikura
  • Patent number: 12527016
    Abstract: Provided is a semiconductor device including: a first trench contact portion provided to an inside of a contact region; a second trench contact portion provided to an inside of an emitter region; a first plug portion of a second conductivity type, which is provided in contact with a lower end of the first trench contact portion and has a higher concentration than a base region; and a second plug portion of a second conductivity type, which is provided in contact with a lower end of the second trench contact portion, is provided to a position closer to a lower surface than the first plug portion, and has a higher concentration than the base region.
    Type: Grant
    Filed: April 21, 2023
    Date of Patent: January 13, 2026
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Seiji Noguchi, Ryutaro Hamasaki, Daisuke Ozaki, Yosuke Sakurai, Takuya Yamada
  • Patent number: 12520570
    Abstract: Provided is a semiconductor device in which one mesa portion of two mesa portions in contact with a gate trench portion is an active mesa portion in which an emitter region of a first conductivity type having a doping concentration higher than that of a drift region is arranged in contact with the gate trench portion, the other mesa portion of two mesa portions in contact with the gate trench portion is a dummy mesa portion having no emitter region, and a dummy contact resistance which is a resistance of the dummy mesa portion and an emitter electrode is 1000 times or more as high as an active contact resistance which is a resistance of the active mesa portion and the emitter electrode.
    Type: Grant
    Filed: December 20, 2022
    Date of Patent: January 6, 2026
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Yosuke Sakurai, Akio Yamano, Seiji Noguchi, Ryutaro Hamasaki, Takuya Yamada, Daisuke Ozaki
  • Patent number: 12471303
    Abstract: Provided is a semiconductor device which includes a semiconductor substrate including a transistor portion and a diode portion. The transistor portion includes an injection suppression region that suppresses injection of a carrier of a second conductivity type at an end portion on the diode portion side in a top view of the semiconductor substrate. Both the transistor portion and the diode portion include a base region of a second conductivity type on a front surface of the semiconductor substrate, the transistor portion further includes an emitter region of a first conductivity type and an extraction region of a second conductivity type having a higher doping concentration than the base region on the front surface of the semiconductor substrate, and the injection suppression region is not provided with the emitter region and the extraction region.
    Type: Grant
    Filed: December 27, 2021
    Date of Patent: November 11, 2025
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Tohru Shirakawa, Daisuke Ozaki, Yasunori Agata
  • Patent number: 12286542
    Abstract: An ink discharging device contains an ink containing an organic solvent with an SP value of from 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature Tg of 0 degrees C. or lower, and water, and an ink discharging unit including a nozzle plate including a liquid repellent layer containing a silicone resin, the ink discharging unit for discharging the ink, wherein the proportion of the organic solvent to the entire of the ink is from 0.5 to 2.5 percent by mass and the proportion of the white pigment to the entire of the ink is from 6 to 15 percent by mass.
    Type: Grant
    Filed: March 16, 2023
    Date of Patent: April 29, 2025
    Assignee: Ricoh Company, Ltd.
    Inventors: Daisuke Ozaki, Toshiyuki Kobashi, Hiroshi Gotou, Ayaka Tanaka, Juichi Furukawa
  • Patent number: 12221549
    Abstract: A set of inkjet inks used for forming an image by application of an ink on a cloth is provided. The set includes an ink and a pre-processing fluid. The pre-processing fluid contains water, a compound that flocculates an anionic compound, and at least one emulsified sizing agent.
    Type: Grant
    Filed: October 27, 2022
    Date of Patent: February 11, 2025
    Assignee: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Toshiyuki Kobashi, Daisuke Ozaki, Juichi Furukawa
  • Publication number: 20250003104
    Abstract: A resin-metal composite body is provided that includes a resin base material having a surface roughness Sq of 1.5 ?m or more and a surface roughness Sku of 4.5 ?m or less, and a metal plating on the resin base material.
    Type: Application
    Filed: June 26, 2024
    Publication date: January 2, 2025
    Applicant: Ricoh Company, Ltd.
    Inventors: Akira Saito, Daisuke Ozaki
  • Patent number: 12183789
    Abstract: Provided is a semiconductor device which includes a semiconductor substrate including a transistor portion and a diode portion. The transistor portion includes an injection suppression region that suppresses injection of a carrier of a second conductivity type at an end portion on the diode portion side in a top view of the semiconductor substrate. The diode portion includes a lifetime control region including a lifetime killer. Both the transistor portion and the diode portion include a base region of a second conductivity type on a surface of the semiconductor substrate, the transistor portion further includes an emitter region of a first conductivity type and an extraction region of a second conductivity type having a higher doping concentration than the base region on the surface of the semiconductor substrate, and the injection suppression region is not provided with the emitter region and the extraction region.
    Type: Grant
    Filed: December 26, 2021
    Date of Patent: December 31, 2024
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Daisuke Ozaki, Tohru Shirakawa, Yasunori Agata
  • Publication number: 20240120412
    Abstract: Provided is a semiconductor device comprising a semiconductor substrate provided with a drift region of a first conductivity type, wherein the substrate includes: an active portion; and a trench portion provided in the active portion at an upper surface of the substrate, the active portion includes: a first region in which trench portions including the trench portion are arrayed at a first trench interval in an array direction; and a second region in which trench portions including the trench portion are arrayed at a second trench interval greater than the first trench interval in the array direction, the first region includes a first bottom region of a second conductivity type provided over bottoms of at least two trench portions of the trench portions, and the second region includes a second bottom region of the second conductivity type provided at a bottom of one trench portion of the trench portions.
    Type: Application
    Filed: December 18, 2023
    Publication date: April 11, 2024
    Inventors: Seiji NOGUCHI, Yosuke SAKURAI, Yoshihiro IKURA, Ryutaro HAMASAKI, Daisuke OZAKI
  • Publication number: 20240006519
    Abstract: Provided is a semiconductor device comprising: a semiconductor substrate including a drift region of a first conductivity type; a base region of a second conductivity type provided between the drift region and the upper surface of the semiconductor substrate; a plurality of trench portions provided from the upper surface of the semiconductor substrate to below the base region; a lower end region of the second conductivity type provided in contact with lower ends of two or more trench portions; a well region of the second conductivity type which is provided from the upper surface of the semiconductor substrate to below the base region, and has a higher doping concentration than the base region; and a high resistance region of the second conductivity type which is arranged between the lower end region and the well region in the top view and has a lower doping concentration than the lower end region.
    Type: Application
    Filed: September 18, 2023
    Publication date: January 4, 2024
    Inventors: Yosuke SAKURAI, Seiji NOGUCHI, Daisuke OZAKI, Ryutaro HAMASAKI, Takuya YAMADA, Yoshihiro IKURA
  • Publication number: 20230395706
    Abstract: Provided is an insulated gate bipolar transistor including: a base region which is provided between an emitter region and a drift region; an accumulation region which is provided between a base region and a drift region, and which has a doping concentration higher than that of the drift region; a gate trench portion which is provided from an upper surface of a semiconductor substrate to a portion below the accumulation region; and a lower end region which is provide to be in contact with a lower end of the gate trench portion; wherein the accumulation region has a first concentration peak in which the doping concentration indicates a maximum value in a depth direction, and a distance between the first concentration peak and the lower end region in a depth direction is less than a distance between the first concentration peak and the base region in the depth direction.
    Type: Application
    Filed: August 18, 2023
    Publication date: December 7, 2023
    Inventors: Takuya YAMADA, Seiji NOGUCHI, Yosuke SAKURAI, Ryutaro HAMASAKI, Daisuke OZAKI
  • Publication number: 20230303869
    Abstract: An ink discharging device contains an ink containing an organic solvent with an SP value of from 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature Tg of 0 degrees C. or lower, and water, and an ink discharging unit including a nozzle plate including a liquid repellent layer containing a silicone resin, the ink discharging unit for discharging the ink, wherein the proportion of the organic solvent to the entire of the ink is from 0.5 to 2.5 percent by mass and the proportion of the white pigment to the entire of the ink is from 6 to 15 percent by mass.
    Type: Application
    Filed: March 16, 2023
    Publication date: September 28, 2023
    Applicant: Ricoh Cpmpany, Ltd.
    Inventors: Daisuke Ozaki, Toshiyuki Kobashi, Hiroshi Gotou, Ayaka Tanaka, Juichi Furukawa
  • Publication number: 20230303872
    Abstract: An ink contains a coloring material, an organic solvent comprising an organic solvent A and a compound represented by the following Chemical Formula I and a resin, wherein the proportion of the entire of the coloring material and the solid content of the resin to the entire of the ink is 15 percent by mass or greater, wherein the organic solvent A contains a polyol with a boiling point of 180 degrees C. or higher and with an equilibrium moisture content of 36 percent by mass or greater at 23 degrees C. and 80 percent RH.
    Type: Application
    Filed: March 22, 2023
    Publication date: September 28, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroshi GOTOU, Toshiyuki Kobashi, Daisuke Ozaki
  • Publication number: 20230261097
    Abstract: Provided is a semiconductor device including: a first trench contact portion provided to an inside of a contact region; a second trench contact portion provided to an inside of an emitter region; a first plug portion of a second conductivity type, which is provided in contact with a lower end of the first trench contact portion and has a higher concentration than a base region; and a second plug portion of a second conductivity type, which is provided in contact with a lower end of the second trench contact portion, is provided to a position closer to a lower surface than the first plug portion, and has a higher concentration than the base region.
    Type: Application
    Filed: April 21, 2023
    Publication date: August 17, 2023
    Inventors: Seiji NOGUCHI, Ryutaro HAMASAKI, Daisuke OZAKI, Yosuke SAKURAI, Takuya YAMADA
  • Publication number: 20230260991
    Abstract: Provided is a semiconductor device in which one mesa portion of two mesa portions in contact with a gate trench portion is an active mesa portion in which an emitter region of a first conductivity type having a doping concentration higher than that of a drift region is arranged in contact with the gate trench portion, the other mesa portion of two mesa portions in contact with the gate trench portion is a dummy mesa portion having no emitter region, and a dummy contact resistance which is a resistance of the dummy mesa portion and an emitter electrode is 1000 times or more as high as an active contact resistance which is a resistance of the active mesa portion and the emitter electrode.
    Type: Application
    Filed: December 20, 2022
    Publication date: August 17, 2023
    Inventors: Yosuke SAKURAI, Akio YAMANO, Seiji NOGUCHI, Ryutaro HAMASAKI, Takuya YAMADA, Daisuke OZAKI
  • Publication number: 20230132661
    Abstract: A set of inkjet inks used for forming an image by application of an ink on a cloth is provided. The set includes an ink and a pre-processing fluid. The pre-processing fluid contains water, a compound that flocculates an anionic compound, and at least one emulsified sizing agent.
    Type: Application
    Filed: October 27, 2022
    Publication date: May 4, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Toshiyuki Kobashi, Daisuke Ozaki, Juichi Furukawa
  • Publication number: 20230124922
    Abstract: Provided is a semiconductor device comprising a semiconductor substrate, the semiconductor substrate comprising an active portion, a second conductivity type circumferential well region surrounding the active portion in a top view, and a trench portion provided in the active portion on an upper surface of the semiconductor substrate, wherein the active portion includes a center portion including a first conductivity type emitter region, and a circumferential portion surrounding the center portion, wherein the center portion includes a second conductivity type active side bottom region provided across bottoms of at least two of the trench portion, the circumferential portion includes a second conductivity type circumferential side bottom region electrically connected to the circumferential well region, facing the active side bottom region, and provided at the bottom of the trench portion, and the active side bottom region and the circumferential side bottom region are provided apart from each other.
    Type: Application
    Filed: December 19, 2022
    Publication date: April 20, 2023
    Inventors: Daisuke OZAKI, Seiji NOGUCHI, Yosuke SAKURAI, Ryutaro HAMASAKI, Takuya YAMADA, Yoshihiro IKURA
  • Publication number: 20230120554
    Abstract: An ink set includes a white ink and a color ink. The white ink and the color ink each independently include water-dispersible resin particles, and a blocked isocyanate compound. A resin of the water-dispersible resin particles includes a crosslinkable functional group. The blocked isocyanate compound includes a functional group that can crosslink with the resin of the water-dispersible resin particles. An absolute value of a difference in static surface tension between the white ink and the color ink at 25° C. is 1.0 mN/m or less. Absolute values of differences in dynamic surface tension between the white ink and the color ink at 25° C. with bubble lifetime of 15 msec, a bubble lifetime of 150 msec, and a bubble lifetime of 1,500 msec are each independently 1.0 mN/m or less. The bubble lifetime is measured according to the maximum bubble pressure method.
    Type: Application
    Filed: September 14, 2022
    Publication date: April 20, 2023
    Applicant: Ricoh Company, Ltd.
    Inventors: Hiroshi Gotou, Toshiyuki Kobashi, Tomohiro Hirade, Daisuke Ozaki
  • Patent number: 11498351
    Abstract: A method for producing a laminated body including a first curable liquid composition and a second curable liquid composition, the method including: forming a first liquid layer formed of the first curable liquid composition; impacting the second curable liquid composition onto the first liquid layer, to form a second liquid droplet layer formed of the second curable liquid composition inside the first liquid layer or at a lower part of the first liquid layer in a direction in which second liquid droplets for the second liquid droplet layer are impacted onto the first liquid layer; and curing the first liquid layer and the second liquid droplet layer.
    Type: Grant
    Filed: November 10, 2020
    Date of Patent: November 15, 2022
    Assignee: Ricoh Company, Ltd.
    Inventors: Manabu Arita, Daisuke Ozaki